- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo NS_DEPRECATED_IOS(2_0, 3_0);


说明方法在2.0时代引入，3.0时代过时

#if __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_5_0
    if([picker respondsToSelector:@selector(dismissModalViewControllerAnimated:)]){
        [picker dismissModalViewControllerAnimated:YES completion:nil];
    }
#else{
     [picker dismissViewControllerAnimated:YES completion:nil];
}
#endif

if([picker respondsToSelector:@selector(imagePickerController:didFinishPickingMediaWithInfo:)]){
    [picker dismissViewControllerAnimated:YES completion:nil];
}else{
    [picker dismissModalViewControllerAnimated:YES];
}

if ([[[UIDevice currentDevice]systemVersion] floatValue] >= 9) {
    if (!self.centralManager.isScanning) {
        [self.centralManager scanForPeripheralsWithServices:nil options:nil];
    }
} else {
    [self.centralManager scanForPeripheralsWithServices:nil options:nil];
}

//指定当前点为 current point，Quartz会跟踪current point一般执行完一个相关函数后，current point都会相应的改变。
CGContextMoveToPoint (
    CGContextRef c,
    CGFloat x,
    CGFloat y
);

Lines：线
//从当前点 画到点,current point 会变化
void CGContextAddLineToPoint (
    CGContextRef c,
    CGFloat x,
    CGFloat y
);

//添加多个路径
void CGContextAddLines (
CGContextRef c,
const CGPoint points[],
size_t count
);

void CGContextAddArc (
    CGContextRef c,    
    CGFloat x,             //圆心的x坐标
    CGFloat y,    //圆心的y坐标
    CGFloat radius,   //圆的半径 
    CGFloat startAngle,    //开始弧度
    CGFloat endAngle,   //结束弧度
    int clockwise          //0表示顺时针，1表示逆时针
 );

void CGContextAddArcToPoint(
    CGContextRef c, 
    CGFloat x1,  //端点1的x坐标
    CGFloat y1,  //端点1的y坐标
    CGFloat x2,  //端点2的x坐标
    CGFloat y2,  //端点2的y坐标
    CGFloat radius //半径
)；

Curves 
 三次曲线函数
 void CGContextAddCurveToPoint (
    CGContextRef c,
    CGFloat cp1x, //控制点1 x坐标
    CGFloat cp1y, //控制点1 y坐标
    CGFloat cp2x, //控制点2 x坐标
    CGFloat cp2y, //控制点2 y坐标
    CGFloat x,  //直线的终点 x坐标
    CGFloat y  //直线的终点 y坐标
 );

 二次曲线函数
 void CGContextAddQuadCurveToPoint (
    CGContextRef c,
    CGFloat cpx,  //控制点 x坐标
    CGFloat cpy,  //控制点 y坐标
    CGFloat x,  //直线的终点 x坐标
    CGFloat y  //直线的终点 y坐标
 );

void CGContextAddEllipseInRect (
    CGContextRef context,
    CGRect rect  //一矩形
);

void CGContextAddRect (
    CGContextRef c,
    CGRect rect
); 

CGContextMoveToPoint设置起点
CGContextClosePath 连接起点和当前点
CGPathCreateMutable 类似于 CGContextBeginPath
CGPathMoveToPoint 类似于 CGContextMoveToPoint
CGPathAddLineToPoint 类似于 CGContextAddLineToPoint
CGPathAddCurveToPoint 类似于 CGContextAddCurveToPoint
CGPathAddEllipseInRect 类似于 CGContextAddEllipseInRect
CGPathAddArc 类似于 CGContextAddArc
CGPathAddRect 类似于 CGContextAddRect
CGPathCloseSubpath 类似于 CGContextClosePath
CGContextAddPath函数把一个路径添加到graphics 

路径填充和描边：
Stroking ：画出路径
Filling ：填充路径的封闭区域

路径和填充的效果
 
//配置样式
//笔触颜色
CGContextSetStrokeColorWithColor(context, [UIColor greenColor].CGColor);
//笔触宽度
CGContextSetLineWidth(context, 20);
//join 拐点样式
//    enum CGLineJoin {
//        kCGLineJoinMiter, //尖的，斜接
//        kCGLineJoinRound, //圆
//        kCGLineJoinBevel //斜面
//    };
CGContextSetLineJoin(context, kCGLineJoinRound);

//Line cap 线的两端的样式
//    enum CGLineCap {
//        kCGLineCapButt,
//        kCGLineCapRound,
//        kCGLineCapSquare
//    };
CGContextSetLineCap(context, kCGLineCapSquare);

//虚线线条样式
CGFloat lengths[] = {10,10};
CGContextSetLineDash(context, 0, lengths, 2);



//路径填充

CGContextStrokePath(ctx); //描出路径
CGContextFillPath(ctx)  使用非零绕数规则填充当前路径
CGContextDrawPath    两个参数决定填充规则，kCGPathFill表示用非零绕数规则，kCGPathEOFill表示用奇偶规则，kCGPathFillStroke表示填充，kCGPathEOFillStroke表示描线，不是填充
CGContextEOFillPath  使用奇偶规则填充当前路径
CGContextFillRect    填充指定的矩形
CGContextFillRects   填充指定的一些矩形
CGContextFillEllipseInRect   填充指定矩形中的椭圆

/*
 *使用performSelector 的多线程
 *优点：简单
 *缺点：没有串行并线队列，不能实现高级线程调度
 */
 
-(void)performSelectorFunction{
    
    NSLog(@"performSelectorFunction start");

    //同步方式执行
    //[self performSelector:@selector(function1)];
    
    //延迟两秒执行,主线程阻塞
    //[self performSelector:@selector(function1) withObject:nil afterDelay:2];

    //主线程上执行，主线程阻塞，waitUntilDone:YES：等待执行完成顺序执行，waitUntilDone:NO 先执行后面语句
    //[self performSelectorOnMainThread:@selector(function1) withObject:nil waitUntilDone:NO];
    
    //子线程上执行
    [self performSelectorInBackground:@selector(function1) withObject:nil];
    
    NSLog(@"performSelectorFunction end");
}

/*
 *使用NSThread 的多线程
 *优点：简单
 *缺点：没有串行并线队列，不能实现高级线程调度,和performSelector是一样的。
 */

-(void)NSThreadFunction{
    
    NSLog(@"NSThreadFunction start");
    
    //线程暂停 2秒
    //[NSThread sleepForTimeInterval:2];
    
    //显示创建的方式执行
    //NSThread *myThread = [[NSThread alloc]initWithTarget:self selector:@selector(function1) object:nil];
    //[myThread start];
    
    //静态方法执行线程
    //[NSThread detachNewThreadSelector:@selector(function1) toTarget:self withObject:nil];
    
    NSLog(@"NSThreadFunction end");
    
}

/*
 *使反面教材，他不是多线程，他只是定时执行任务
 */

-(void)NSTimerFunction{
    
    NSLog(@"NSTimerFunction start");
    
    //定时执行任务，可以重复和不重复
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(function1) userInfo:nil repeats:NO];
    
    //暂时停止定时器
    //[timer setFireDate:[NSDate distantFuture]];
    //重新开启定时器
    //[timer setFireDate:[NSDate distantPast]];
    //永久通知定时器
    //[timer invalidate];
    //timer = nil;
    
    NSLog(@"NSTimerFunction end");
    
}

// dispatch_sync 同步方式执行：
 dispatch_sync(dispatch_get_global_queue(0, 0), ^{
      // something
 });


// dispatch_async 异步执行：
 dispatch_async(dispatch_get_global_queue(0, 0), ^{
      // something
 });

 // dispatch_async：主线程执行：
 dispatch_async(dispatch_get_main_queue(), ^{
      // something
 });

 // dispatch_once：一次性执行：
 static dispatch_once_t onceToken;
 dispatch_once(&onceToken, ^{
     // code to be executed once
 });

 //dispatch_time_t ：延迟2秒执行：
 double delayInSeconds = 2.0;
 dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
 dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
     // code to be executed on the main queue after delay
 });

 //dispatch_group_t： 合并汇总结果
 dispatch_group_t group = dispatch_group_create();
 dispatch_group_async(group, dispatch_get_global_queue(0,0), ^{
      // 并行执行的线程一
 });
 dispatch_group_async(group, dispatch_get_global_queue(0,0), ^{
      // 并行执行的线程二
 });
 dispatch_group_notify(group, dispatch_get_global_queue(0,0), ^{
      // 汇总结果
 });


 //dispatch_barrier_async :作用是在并行队列中，等待前面的队列执行完成后再继续往下执行
dispatch_queue_t concurrentQueue = dispatch_queue_create("my.concurrent.queue", DISPATCH_QUEUE_CONCURRENT);
dispatch_async(concurrentQueue, ^(){
    NSLog(@"dispatch-1");
});
dispatch_async(concurrentQueue, ^(){
    NSLog(@"dispatch-2");
});
dispatch_barrier_async(concurrentQueue, ^(){
    NSLog(@"dispatch-barrier"); 
});
dispatch_async(concurrentQueue, ^(){
    NSLog(@"dispatch-3");
});
dispatch_async(concurrentQueue, ^(){
    NSLog(@"dispatch-4");
});

//dispatch_apply：将一个指定的block执行指定的次数，常用语block数组。在一般方法中虽然block中的方法并不是顺序执行，但是由于apply是线程同步的，
//所以print(dispatch_apply done);一定最后执行。常常可以这样用：
let globalQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
dispatch_async(globalQueue, { () -> Void in
    dispatch_apply(10, globalQueue) { (index) -> Void in
        print(index)
    }
    print("completed")
})
print("在dispatch_apply之前") 


//dispatch_suspend / dispatch_resume
//暂停
dispatch_suspend(globalQueue)
//恢复
dispatch_resume(globalQueue)

//Dispatch Semaphore 这个是线程的信号量，比较复杂

-(BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection{
    return true;
}
- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge{
    NSLog(@"didReceiveAuthenticationChallenge %@ %zd", [[challenge protectionSpace] authenticationMethod], (ssize_t) [challenge previousFailureCount]);
    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]){
        [[challenge sender]  useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
        [[challenge sender]  continueWithoutCredentialForAuthenticationChallenge: challenge];
    }
}

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace{
       return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<NSURLConnectionDataDelegate>

@end

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //string 转 url编码
    NSString *urlString = @"https://api.github.com/users/coolnameismy";
    NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]];

    
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
    NSURLConnectionDataDelegate *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
    
    [connection start];
}

//请求失败
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
    NSLog(@"=================didFailWithError=================");
    NSLog(@"error:%@",error);
}

//重定向
- (nullable NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(nullable NSURLResponse *)response{
    NSLog(@"=================request redirectResponse=================");
    NSLog(@"request:%@",request);
    return request;
}

//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
    NSLog(@"=================didReceiveResponse=================");
    NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;
    NSLog(@"response:%@",resp);
}

//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
    NSLog(@"=================didReceiveData=================");
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
    NSLog(@"data:%@",dic);
}

//- (nullable NSInputStream *)connection:(NSURLConnection *)connection needNewBodyStream:(NSURLRequest *)request{
//    
//}

//上传数据委托，用于显示上传进度
- (void)connection:(NSURLConnection *)connection   didSendBodyData:(NSInteger)bytesWritten
 totalBytesWritten:(NSInteger)totalBytesWritten
totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite{
    NSLog(@"=================totalBytesWritten=================");
}

//- (nullable NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse{
//    
//}

//完成请求
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
    NSLog(@"=================connectionDidFinishLoading=================");
}


#pragma mark -https认证
-(BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection{
    return true;
}
- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge{
    NSLog(@"didReceiveAuthenticationChallenge %@ %zd", [[challenge protectionSpace] authenticationMethod], (ssize_t) [challenge previousFailureCount]);
    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]){
        [[challenge sender]  useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
        [[challenge sender]  continueWithoutCredentialForAuthenticationChallenge: challenge];
    }
}

- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace{
       return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

//获取cookie
NSDictionary *headers = [((NSHTTPURLResponse *)resp) allHeaderFields];
NSLog(@"headers:%@",headers);
NSDictionary *cookies = [NSHTTPCookie cookiesWithResponseHeaderFields:headers forURL:[NSURL URLWithString:@"http://localhost/"]];

for (NSHTTPCookie *cookie in cookies) {
    NSLog(@"cookie:%@",cookie);
    if ([[cookie name] isEqualToString:@"JSESSIONID"]) {
        NSLog(@"session id is %@",[cookie value]);
    }
}

//获取本地cookie
NSHTTPCookieStorage *httpCookiesStorage =  [NSHTTPCookieStorage sharedHTTPCookieStorage];
NSDictionary *cookies = [httpCookiesStorage cookiesForURL:[NSURL URLWithString:@"http://localhost/"]];
for (NSHTTPCookie *cookie in cookies) {
    NSLog(@"cookie:%@",cookie);
}

//客户端设置cookie
-(void)clientSetCookie{
    
    NSDictionary *prop1 = [NSDictionary dictionaryWithObjectsAndKeys:
                           @"a",NSHTTPCookieName,
                           @"aaa",NSHTTPCookieValue,
                           @"/",NSHTTPCookiePath,
                           [NSURL URLWithString:@"http://localhost/"],NSHTTPCookieOriginURL,
                           [NSDate dateWithTimeIntervalSinceNow:60],NSHTTPCookieExpires,
                           nil];
    NSDictionary *prop2 = [NSDictionary dictionaryWithObjectsAndKeys:
                           @"b",NSHTTPCookieName,
                           @"bbb",NSHTTPCookieValue,
                           @"/",NSHTTPCookiePath,
                           [NSURL URLWithString:@"http://localhost/"],NSHTTPCookieOriginURL,
                           [NSDate dateWithTimeIntervalSinceNow:60],NSHTTPCookieExpires,
                           nil];
    
    NSHTTPCookie *cookie1 = [NSHTTPCookie cookieWithProperties:prop1];
    NSHTTPCookie *cookie2 = [NSHTTPCookie cookieWithProperties:prop2];

    //单个设置
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie:cookie1];
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie:cookie2];
    
    //批量设置
//    NSArray *cookies = @[cookie1,cookie2,cookie3];
//    [[NSHTTPCookieStorage sharedHTTPCookieStorage]setCookies:cookies forURL:[NSURL URLWithString:@"http://localhost/"] mainDocumentURL:nil];
    
    //设置cookie本地缓存策略
    //NSHTTPCookieAcceptPolicyAlways:保存所有cookie，这个是默认值
    //NSHTTPCookieAcceptPolicyNever:不保存任何响应头中的cookie
    //NSHTTPCookieAcceptPolicyOnlyFromMainDocumentDomain:只保存域请求匹配的cookie

    [[NSHTTPCookieStorage sharedHTTPCookieStorage]setCookieAcceptPolicy:NSHTTPCookieAcceptPolicyAlways];

    NSLog(@"设置完成");
}

#pragma mark -客户端删除cookie
//根据url和name删除cookie
-(void)deleteCookie:(NSString *)cookieName url:(NSURL *)url{
    //根据url找到所属的cookie集合
    NSArray *cookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage]cookiesForURL:url];
    for (NSHTTPCookie *cookie in cookies) {
        if([cookie.name isEqualToString:cookieName]){
            [[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie];
            NSLog(@"删除cookie:%@",cookieName);
        }
    }
}
//删除全部cookies
-(void)deleteCookies{
    for (NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage]cookies]) {
        [[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie];
    }
    NSLog(@"删除完成");
}

//设置cookie本地缓存策略
//NSHTTPCookieAcceptPolicyAlways:保存所有cookie，这个是默认值
//NSHTTPCookieAcceptPolicyNever:不保存任何响应头中的cookie
//NSHTTPCookieAcceptPolicyOnlyFromMainDocumentDomain:只保存域请求匹配的cookie

#import "Roommate.h"
@interface Roommate (Roommate_Say)
-(void) introduceSelf;
//-(void)hello:(NSString *) str;
@end

#import "Roommate+Roommate_Say.h"
@implementation Roommate (Roommate_Say)
-(void) introduceSelf{   
    NSLog(@"my name is liuyanwei");
}
@end

#import <Foundation/Foundation.h>
@protocol RoommateDelegate<NSObject>
@optional
-(void)showMessage:(NSString *)msg;
@required
-(void)mustShowMessage:(NSString *)msg;
@end

--1基本用法
 void(^myblock)(NSString *msg) = ^(NSString *msg){
        NSLog(@"%@",msg);
    };    
    myblock(@"hello");

--2先定义在类方法中后使用
//方法定义
-(void)showMessageWithBlock:(NSString *) msg block:(void (^)(NSString *msg))block
{
    block(msg);
}

//方法定义的简写
typedef void (^ShowMessageBlock)(NSString *msg);
-(void)showMessageWithBlock1:(NSString *) msg block:(ShowMessageBlock)block{
    block(msg);
}
//方法的使用
[roommate showMessageWithBlock:@"hello" block:^(NSString *msg) {
        NSLog(@"%@",msg);
}];

--3 注意点
若想在block中修改本地变量，需要声明变量类型： __block NSString *localmsg = @"local string";

/*NSRange表示一个范围*/
void test1(){
    NSRange rg={3,5};//第一参数是起始位置第二个参数是长度
    //NSRange rg;
    //rg.location=3;
    //rg.length=5;
    //NSRange rg={.location=3,.length=5};
    //常用下面的方式定义 NSRange rg2=NSMakeRange(3,5);//使用NSMakeRange定义一个NSRange 
    //打印NSRange可以使用Foundation中方法 NSLog(@"rg2 is %@", NSStringFromRange(rg2));//注意不能直接NSLog(@"rg2 is %@", rg2)，因为rg2不是对象（准确的说%@是指针）而是结构体
}
/*NSPoint表示一个点*/
void test2(){
    NSPoint p=NSMakePoint(10, 15);//NSPoint其实就是CGPoint
    //这种方式比较常见 NSPoint p2=CGPointMake(10, 15);
    NSLog(NSStringFromPoint(p2));
}
/*NSSize表示大小*/
void test3(){
    NSSize s=NSMakeSize(10, 15);//NSSize其实就是CGSize
    //这种方式比较常见 CGSize s2=CGSizeMake(10, 15);
    NSLog(NSStringFromSize(s2));
}
/*NSRect表示一个矩形*/
void test4(){
    NSRect r=NSMakeRect(10, 5, 100, 200);//NSRect其实就是CGRect
    //这种方式比较常见 NSRect r2=CGRectMake(10, 5, 100, 200);
    NSLog(NSStringFromRect(r2));
}

    NSDate *date1=[NSDate date];//获得当前日期
    NSLog(@"%@",date1); //结果：2014-07-16 07:25:28 +0000
    
    NSDate *date2=[NSDate dateWithTimeIntervalSinceNow:100];//在当前日期的基础上加上100秒，注意在ObjC中多数时间单位都是秒
    NSLog(@"%@",date2); //结果：2014-07-16 07:27:08 +0000
    
    NSDate *date3=[NSDate distantFuture];//随机获取一个将来的日期
    NSLog(@"%@",date3); //结果：4001-01-01 00:00:00 +0000
    
    NSTimeInterval time=[date2 timeIntervalSinceDate:date1];//日期之差,返回单位为秒
    NSLog(@"%f",time); //结果：100.008833
    
    NSDate *date5=[date1 earlierDate:date3];//返回比较早的日期
    NSLog(@"%@",date5); //结果：2014-07-16 07:25:28 +0000
    
    //日期格式化
    NSDateFormatter *formater1=[[NSDateFormatter alloc]init];
    formater1.dateFormat=@"yy-MM-dd HH:mm:ss";
    NSString *datestr1=[formater1 stringFromDate:date1];
    NSLog(@"%@",datestr1); //结果：14-07-16 15:25:28
    //字符串转化为日期
    NSDate *date6=[formater1 dateFromString:@"14-02-14 11:07:16"];
    NSLog(@"%@",date6); //结果：2014-02-14 03:07:16 +0000


````objc


##  字符串

````objc

/**字符串操作*/
void test1(){
    char *str1="C string";//这是C语言创建的字符串
    NSString *str2=@"OC string";//ObjC字符串需要加@，并且这种方式创建的对象不需要自己释放内存

    //下面的创建方法都应该释放内存
    NSString *str3=[[NSString alloc] init];
    str3=@"OC string";
    NSString *str4=[[NSString alloc] initWithString:@"Objective-C string"];
    NSString *str5=[[NSString alloc] initWithFormat:@"age is %i,name is %.2f",19,1.72f];
    NSString *str6=[[NSString alloc] initWithUTF8String:"C string"];//C语言的字符串转换为ObjC字符串

    //以上方法都有对应静态方法（一般以string开头）,不需要管理内存（系统静态方法一般都是自动释放）
    NSString *str7=[NSString stringWithString:@"Objective-C string"];
}
void test2(){
    NSLog(@"\"Hello world!\" to upper is %@",[@"Hello world!" uppercaseString]);
    //结果："Hello world!" to upper is HELLO WORLD!
    NSLog(@"\"Hello world!\" to lowwer is %@",[@"Hello world!" lowercaseString]);
    //结果："Hello world!" to lowwer is hello world!
     
    //首字母大写，其他字母小写
    NSLog(@"\"Hello world!\" to capitalize is %@",[@"Hello world!" capitalizedString]);
    //结果："Hello world!" to capitalize is Hello World!
     
    BOOL result= [@"abc" isEqualToString:@"aBc"];
    NSLog(@"%i",result);
    //结果：0
    NSComparisonResult result2= [@"abc" compare:@"aBc"];//如果是[@"abc" caseInsensitiveCompare:@"aBc"]则忽略大小写比较
    if(result2==NSOrderedAscending){
        NSLog(@"left<right.");
    }else if(result2==NSOrderedDescending){
        NSLog(@"left>right.");
    }else if(result2==NSOrderedSame){
        NSLog(@"left=right.");
    }
    //结果：left>right.
}
void test3(){
    NSLog(@"has prefix ab? %i",[@"abcdef" hasPrefix:@"ab"]);
    //结果：has prefix ab? 1
    NSLog(@"has suffix ab? %i",[@"abcdef" hasSuffix:@"ef"]);
    //结果：has suffix ab? 1
    NSRange range=[@"abcdefabcdef" rangeOfString:@"cde"];//注意如果遇到cde则不再往后面搜索,如果从后面搜索或其他搜索方式可以设置第二个options参数
    if(range.location==NSNotFound){
        NSLog(@"not found.");
    }else{
        NSLog(@"range is %@",NSStringFromRange(range));
    }
    //结果：range is {2, 3}
}
//字符串分割
void test4(){
    NSLog(@"%@",[@"abcdef" substringFromIndex:3]);//从第三个索引开始（包括第三个索引对应的字符）截取到最后一位
    //结果：def
    NSLog(@"%@",[@"abcdef" substringToIndex:3]);////从0开始截取到第三个索引（不包括第三个索引对应的字符）
    //结果：abc
    NSLog(@"%@",[@"abcdef" substringWithRange:NSMakeRange(2, 3)]);
    //结果：cde
    NSString *str1=@"12.abcd.3a";
    NSArray *array1=[str1 componentsSeparatedByString:@"."];//字符串分割
    NSLog(@"%@",array1);
     /*结果：
      (
         12,
         abcd,
         3a
      )
      */
 
}
//其他操作
void test5(){
    NSLog(@"%i",[@"12" intValue]);//类型转换
    //结果：12
    NSLog(@"%zi",[@"hello world,世界你好！" length]);//字符串长度注意不是字节数
    //结果：17
    NSLog(@"%c",[@"abc" characterAtIndex:0]);//取出制定位置的字符
    //结果：a
    const char *s=[@"abc" UTF8String];//转换为C语言字符串
    NSLog(@"%s",s);
    //结果：abc
}

int main(int argc, const char * argv[]) {
    test1();
    test2();
    test3();
    test4();
    test5();
    return 0;
}
/*可变字符串，注意NSMutableString是NSString子类*/
    //注意虽然initWithCapacity分配字符串大小，但是不是绝对的不可以超过此范围，声明此变量对性能有好处
    NSMutableString *str1= [[NSMutableString alloc] initWithCapacity:10];
    [str1 setString:@"hello"];//设置字符串
    NSLog(@"%@",str1);
    //结果：hello

    [str1 appendString:@",world!"];//追加字符串
    NSLog(@"%@",str1);
    //结果：hello,world!

    [str1 appendFormat:@"我的年龄是%i。dear,I love you.",18];
    NSLog(@"%@",str1);
    //结果：hello,world!我的年龄是18。dear,I love you.
    
    //替换字符串
    NSRange range=[str1 rangeOfString:@"dear"];
    [str1 replaceCharactersInRange:range withString:@"Honey"];
    NSLog(@"%@",str1);
    //结果：hello,world!我的年龄是18。Honey,I love you.
    
    //插入字符串
    [str1 insertString:@"My name is Kenshin." atIndex:12];
    NSLog(@"%@",str1);
    //结果：hello,world!My name is Kenshin.我的年龄是18。Honey,I love you.
    
    //删除指定字符串
    [str1 deleteCharactersInRange:[str1 rangeOfString:@"My name is Kenshin."]];//删除指定范围的字符串
    NSLog(@"%@",str1);
    //结果：hello,world!我的年龄是18。Honey,I love you.
  

````  
    
## 数组

````objc

//NSArray长度不可变所以初始化的时候就赋值，并且最后以nil结尾
    //此外需要注意NSArray不能存放C语言的基础类型
    NSObject *obj=[[NSObject alloc]init];
    //NSArray *array1=[[NSArray alloc] initWithObjects:@"abc",obj,@"cde",@"opq", nil];
    NSArray *array1=[NSArray arrayWithObjects:@"abc",obj,@"cde",@"opq",@25, nil];
    NSLog(@"%zi",array1.count);//数组长度,结果：5
    NSLog(@"%i",[array1 containsObject:@"cde"]);//是否包含某个对象，结果：1
    NSLog(@"%@",[array1 lastObject]);//最后一个对象，结果：25
    NSLog(@"%zi",[array1 indexOfObject:@"abc"]);//对象所在的位置：0
    
    Person *person1=[Person personWithName:@"Kenshin"];
    Person *person2=[Person personWithName:@"Kaoru"];
    Person *person3=[Person personWithName:@"Rosa"];
    NSArray *array2=[[NSArray alloc]initWithObjects:person1,person2,person3, nil];
    [array2 makeObjectsPerformSelector:@selector(showMessage:) withObject:@"Hello,world!"];//执行所有元素的showMessage方法,后面的参数最多只能有一个
    /*结果：
     My name is Kenshin,the infomation is "Hello,world!".
     My name is Kaoru,the infomation is "Hello,world!".
     My name is Rosa,the infomation is "Hello,world!".
     */
}
//数组的遍历
void test2(){
    NSObject *obj=[[NSObject alloc]init];
    NSArray *array=[[NSArray alloc] initWithObjects:@"abc",obj,@"cde",@"opq",@25, nil];
    //方法1
    for(int i=0,len=array.count;i<len;++i){
        NSLog(@"method1:index %i is %@",i,[array objectAtIndex:i]);
    }
    /*结果：
     method1:index 0 is abc
     method1:index 1 is <NSObject: 0x100106de0>
     method1:index 2 is cde
     method1:index 3 is opq
     method1:index 4 is 25
     */
    
    
    //方法2
    for(id obj in array){
        NSLog(@"method2:index %zi is %@",[array indexOfObject:obj],obj);
    }
    /*结果：
     method2:index 0 is abc
     method2:index 1 is <NSObject: 0x100602f00>
     method2:index 2 is cde
     method2:index 3 is opq
     method2:index 4 is 25
     */
    
    
    //方法3,利用代码块方法
    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        NSLog(@"method3:index %zi is %@",idx,obj);
        if(idx==2){//当idx=2时设置*stop为YES停止遍历
            *stop=YES;
        }
    }];
    /*结果：
     method3:index 0 is abc
     method3:index 1 is <NSObject: 0x100106de0>
     method3:index 2 is cde
     */
    
    
    //方法4，利用迭代器
    //NSEnumerator *enumerator= [array objectEnumerator];//获得一个迭代器
    NSEnumerator *enumerator=[array reverseObjectEnumerator];//获取一个反向迭代器
    //NSLog(@"all:%@",[enumerator allObjects]);//获取所有迭代对象，注意调用完此方法迭代器就遍历完了，下面的nextObject就没有值了
    id obj2=nil;
    while (obj2=[enumerator nextObject]) {
        NSLog(@"method4:%@",obj2);
    }
    /*结果：
     method4:25
     method4:opq
     method4:cde
     method4:<NSObject: 0x100106de0>
     method4:abc
     */
}
//数组派生出新的数组
void test3(){
    NSArray *array=[NSArray arrayWithObjects:@"1",@"2",@"3", nil];
    NSArray *array2=[array arrayByAddingObject:@"4"];//注意此时array并没有变
    NSLog(@"%@",array2);
    /*结果：
     (
         1,
         2,
         3,
         4
     )
     */
    
    
    NSLog(@"%@",[array2 arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"5",@"6", nil]]);//追加形成新的数组
    /*结果：
     (
         1,
         2,
         3,
         4,
         5,
         6
     )
     */
    
    
    NSLog(@"%@",[array2 subarrayWithRange:NSMakeRange(1, 3)]);//根据一定范围取得生成一个新的数组
    /*结果：
     (
         2,
         3,
         4
     )
     */
    

    void test1(){
    NSDictionary *dic1=[NSDictionary dictionaryWithObject:@"1" forKey:@"a"];
    NSLog(@"%@",dic1);
    /*结果：
     {
        a = 1;
     }
     */
    
    //常用的方式
    NSDictionary *dic2=[NSDictionary dictionaryWithObjectsAndKeys:
                        @"1",@"a",
                        @"2",@"b",
                        @"3",@"c",
                        nil];
    NSLog(@"%@",dic2);
    /*结果：
     {
         a = 1;
         b = 2;
         c = 3;
     }
     */
    
    
    NSDictionary *dic3=[NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"1",@"2", nil] forKeys:[NSArray arrayWithObjects:@"a",@"b", nil]];
    NSLog(@"%@",dic3);
    /*结果：
     {
         a = 1;
         b = 2;
     }
     */
    
    
    //更简单的方式
    NSDictionary *dic4=@{@"1":@"a",@"2":@"b",@"3":@"c"};
    NSLog(@"%@",dic4);
    /*结果：
     {
         1 = a;
         2 = b;
         3 = c;
     }
     */
}
  //遍历1
    for (id key in dic1) {//注意对于字典for遍历循环的是key
        NSLog(@"%@=%@",key,[dic1 objectForKey:key]);
    }
    /*结果：
     d=2
     b=2
     c=3
     a=1
     */
    
    //遍历2
    NSEnumerator *enumerator=[dic1 keyEnumerator];//还有值的迭代器[dic1 objectEnumerator]
    id key=nil;
    while (key=[enumerator nextObject]) {
        NSLog(@"%@=%@",key,[dic1 objectForKey:key]);
        
    }
    /*结果：
     d=2
     b=2
     c=3
     a=1
     */
    
    //遍历3
    [dic1 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        NSLog(@"%@=%@",key,obj);
    }];
    /*结果：
     d=2
     b=2
     c=3
     a=1
     */

+(NSNumber *)numberWithChar:(char)value;

+(NSNumber *)numberWithInt:(int)value;

+(NSNumber *)numberWithFloat:(float)value;

+(NSNumber *)numberWithDouble:(double)value;

+(NSNumber *)numberWithBool:(BOOL)value;

+(NSNumber *)numberWithInteger:(NSInteger)value;

拆箱的过程就更加简单了，可以调用如下方法：

-(char)charValue;

-(int)intValue;

-(float)floatValue;

-(double)doubleValue;

-(BOOL)boolValue;

+(NSValue *)valueWithPoint:(NSPoint)point;

+(NSValue *)valueWithSize:(NSSize)size;

+(NSValue *)valueWithRect:(NSRect)rect;

对应的拆箱方法：

-(NSPoint)pointValue;

-(NSSize)sizeValue;

-(NSRect)rectValue;

+(NSValue *)valueWithBytes:(const void *)value objCType:(const char *)type;
示例
typedef struct {
    int year;
    int month;
    int day;
} Date;

##使用:

##  选项 NS_OPTIONS
 
//NS_OPTIONS，定义选项
typedef NS_OPTIONS(NSUInteger, MyOption) {
MyOptionNone = 0, //二进制0000,十进制0
MyOption1 = 1 << 0,//0001,1
MyOption2 = 1 << 1,//0010,2
MyOption3 = 1 << 2,//0100,4
MyOption4 = 1 << 3,//1000,8
};

//声明定义枚举变量
MyOption option = MyOption1 | MyOption2;//0001 | 0010 = 0011,3

//检查是否包含某选型
if ( option & MyOption3 ){ //0011 & 0100 = 0000
     //包含MyOption3
}else{
     //不包含MyOption3
}

```

//增加选项:
option = option | MyOption4;//0011 | 1000 = 1011, 11
//减少选项
option = option & (~MyOption4);//1011 & (~1000) = 1011 & 0111 = 0011, 3

//NSNumber是NSValue的子类，而NSValue可以包装任何类型，包括结构体
void test1(){
    //如果我们自己定义的结构体包装
    Date date={2014,2,28};
    char *type=@encode(Date);
    NSValue *value=[NSValue value:&date withObjCType:type];//第一参数传递结构体地址，第二个参数传递类型字符串
    NSArray *array=[NSArray arrayWithObject:value];
    NSLog(@"%@",array2);
    /*结果：
     (
        "<de070000 02000000 1c000000>"
     )
     */
    
    Date date2;
    [value getValue:&date];//取出对应的结构体，注意没有返回值
    //[value3 objCType]//取出包装内容的类型
    NSLog(@"%i,%i,%i",date2.year,date2.month,date2.day); //结果：2014,2,28
    
}

NSLog(@"%i",[person1 isKindOfClass:[NSObject class]]); //判断一个对象是否为某种类型（如果是父类也返回YES），结果：1
NSLog(@"%i",[person1 isMemberOfClass:[NSObject class]]); //判断一个对象是否是某个类的实例化对象，结果：0
NSLog(@"%i",[person1 isMemberOfClass:[Person class]]); //结果：1
NSLog(@"%i",[person1 conformsToProtocol:@protocol(NSCopying)]);//是否实现了某个协议，结果：0
NSLog(@"%i",[person1 respondsToSelector:@selector(showMessage:)]);//是否存在某个方法，结果：1
//直接调用一个方法
[person1 showMessage:@"Hello,world!"];
//动态调用一个方法，注意如果有参数那么参数类型只能为ObjC对象，并且最多只能有两个参数
[person1 performSelector:@selector(showMessage:) withObject:@"Hello,world!"];
  

Class myClass=NSClassFromString(@"Person");//根据类名生成类

/*目录操作*/
void test1(){
    //文件管理器是专门用于文件管理的类
    NSFileManager *manager=[NSFileManager defaultManager];
    
    //获得当前程序所在目录(当然可以改变)
    NSString *currentPath=[manager currentDirectoryPath];
    NSLog(@"current path is :%@",currentPath);
    //结果：/Users/kenshincui/Library/Developer/Xcode/DerivedData/FoundationFramework-awxjohcpgsqcpsanqofqogwbqgbx/Build/Products/Debug
    
    //创建目录
    NSString *myPath=@"/Users/kenshincui/Desktop/myDocument";
    BOOL result= [manager createDirectoryAtPath:myPath withIntermediateDirectories:YES attributes:nil error:nil];
    if(result==NO){
        NSLog(@"Couldn't create directory!");
    }
    
    //目录重命名，如果需要删除目录只要调用removeItemAtPath:<#(NSString *)#> error:<#(NSError **)#>
    NSError *error;
    NSString *newPath=@"/Users/kenshincui/Desktop/myNewDocument";
    if([manager moveItemAtPath:myPath toPath:newPath error:&error]==NO){
        NSLog(@"Rename directory failed!Error infomation is:%@",error);
    }
    
    //改变当前目录
    if([manager changeCurrentDirectoryPath:newPath]==NO){
        NSLog(@"Change current directory failed!");
    }
    NSLog(@"current path is :%@",[manager currentDirectoryPath]);
    //结果：current path is :/Users/kenshincui/Desktop/myNewDocument
    
    //遍历整个目录
    NSString *path;
    NSDirectoryEnumerator *directoryEnumerator= [manager enumeratorAtPath:newPath];
    while (path=[directoryEnumerator nextObject]) {
        NSLog(@"%@",path);
    }
    /*结果：
     documents
     est.txt
    */
    
    //或者这样遍历
    NSArray *paths= [manager contentsOfDirectoryAtPath:newPath error:nil];
    NSObject *p;
    for (p in paths) {
        NSLog(@"%@",p);
    }
    /*结果：
     documents
     est.txt
     */
}

/*文件操作*/
void test2(){
    NSFileManager *manager=[NSFileManager defaultManager];
    NSString *filePath=@"/Users/kenshincui/Desktop/myNewDocument/test.txt";
    NSString *filePath2=@"/Users/kenshincui/Desktop/test.txt";
    NSString *newPath=@"/Users/kenshincui/Desktop/myNewDocument/test2.txt";
    
    //判断文件是否存在，这个方法也可以判断目录是否存在，这要后面的参数设置位YES
    if ([manager fileExistsAtPath:filePath isDirectory:NO]) {
        NSLog(@"File exists！");
    }
    
    //文件是否可读
    if([manager isReadableFileAtPath:filePath]){
        NSLog(@"File is readable!");
    }
    
    //判断两个文件内容是否相等
    if ([manager contentsEqualAtPath:filePath andPath:filePath2]) {
        NSLog(@"file1 equals file2");
    }
    
    //文件重命名，方法类似于目录重命名
    if (![manager moveItemAtPath:filePath toPath:newPath error:nil]) {
        NSLog(@"Rename file1 failed!");
    }
    
    //文件拷贝
    NSString *filePath3=@"/Users/kenshincui/Desktop/test3.txt";
    if(![manager copyItemAtPath:newPath toPath:filePath3 error:nil]){
        NSLog(@"Copy failed!");
    }
    
    //读取文件属性
    NSDictionary *attributes;
    if ((attributes=[manager attributesOfItemAtPath:newPath error:nil])==nil) {
        NSLog(@"Read attributes failed!");
    }
    for (NSObject *key in attributes) {
        NSLog(@"%@=%@",key,attributes[key]);
    }
    /*结果：
         NSFileOwnerAccountID=501
         NSFileHFSTypeCode=0
         NSFileSystemFileNumber=1781953
         NSFileExtensionHidden=0
         NSFileSystemNumber=16777218
         NSFileSize=27
         NSFileGroupOwnerAccountID=20
         NSFileOwnerAccountName=kenshincui
         NSFileCreationDate=2014-07-28 11:47:58 +0000
         NSFilePosixPermissions=420
         NSFileHFSCreatorCode=0
         NSFileType=NSFileTypeRegular
         NSFileExtendedAttributes={
         "com.apple.TextEncoding" = <7574662d 383b3133 34323137 393834>;
         }
         NSFileGroupOwnerAccountName=staff
         NSFileReferenceCount=1
         NSFileModificationDate=2014-07-28 11:47:58 +0000
     */
    
    //删除文件
    [manager removeItemAtPath:newPath error:nil];
    
}
//文件操作--文件内容操作（NSData，非结构化字节流对象，有缓冲区管理机制，可用于网络传输）
void test3(){
    NSFileManager *manager=[NSFileManager defaultManager];
    NSString *filePath=@"/Users/kenshincui/Desktop/myNewDocument/test2.txt";
    NSData *data=[manager contentsAtPath:filePath];
    NSLog(@"%@",data);//存储的是二进制字节流
    //结果:<68656c6c 6f20776f 726c642c e4b896e7 958ce4bd a0e5a5bd efbc81>
    
    //NSData转化成字符串
    NSString *str1=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"%@",str1);
    //结果：hello world,世界你好！
    
    //字符串转化成NSData
    NSString *str2=@"Kenshin";
    NSData *data2=[str2 dataUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"%@",data2);
    
    //当然一般如果仅仅是简单读取文件内容，直接用户NSString方法即可
    NSString *content=[NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"%@",content);
    //结果：hello world,世界你好！
    
}
//文件操作--细粒度控制文件,文件操作柄
void test4(){
    NSFileManager *manager=[NSFileManager defaultManager];
    NSString *filePath=@"/Users/kenshincui/Desktop/myNewDocument/test2.txt";
    
    //以只读方式打开文件
    NSFileHandle *fileHandle=[NSFileHandle fileHandleForReadingAtPath:filePath];//注意这个方法返回类型为instancetype，也就是说对于上面的NSFileHandle它的返回类型也是NSFileHandle
    NSData *data= [fileHandle readDataToEndOfFile];//完整读取文件
    NSString *newPath=@"/Users/kenshincui/Desktop/test4.txt";
    [manager createFileAtPath:newPath contents:nil attributes:nil];
    NSFileHandle *fileHandle2=[NSFileHandle fileHandleForWritingAtPath:newPath];//以可写方式打开文件
    [fileHandle2 writeData:data];//写入文件内容
    
    [fileHandle2 closeFile];//关闭文件

    
    //定位到指定位置,默认在文件开头
    [fileHandle seekToFileOffset:12];
    NSData *data2= [fileHandle readDataToEndOfFile];
    NSLog(@"data2=%@",[[NSString alloc]initWithData:data2 encoding:NSUTF8StringEncoding]);
    //结果：data2=世界你好！
    
    [fileHandle seekToFileOffset:6];
    NSData *data3=[fileHandle readDataOfLength:5];
    NSLog(@"data3=%@",[[NSString alloc]initWithData:data3 encoding:NSUTF8StringEncoding]);
    //结果：data3=world
    
    [fileHandle closeFile];
    
}

//文件路径
void test5(){
    NSString *filePath=@"/Users/kenshincui/Desktop/myDocument";
    NSString *filePath2=@"/Users/kenshincui/Desktop/test.txt";

    //临时文件所在目录
    NSString *path=NSTemporaryDirectory();
    NSLog(@"temporary directory is :%@",path);
    //结果：/var/folders/h6/lss6gncs509c2pgzgty3wd_40000gn/T/

    NSString *lastComponent= [filePath lastPathComponent];
    NSLog(@"%@",lastComponent); //结果：myDocument
    
    NSLog(@"%@",[filePath stringByDeletingLastPathComponent]);
    //结果：/Users/kenshincui/Desktop
    NSLog(@"%@",[filePath stringByAppendingPathComponent:@"Pictrues"]);
    //结果：/Users/kenshincui/Desktop/myDocument/Pictrues
    NSLog(@"%@",[filePath2 pathExtension]);
    //结果：txt
    
    [[filePath pathComponents] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        NSLog(@"%i=%@",idx,obj);
    }];
    /*结果：
     0=/
     1=Users
     2=kenshincui
     3=Desktop
     4=myDocument
     */
    
    
}

//文件操作--NSURL
void test6(){
    NSURL *url=[NSURL URLWithString:@"http://developer.apple.com"];
    NSString *str1=[NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"%@",str1);
}

//文件操作--NSBundle，程序包，一般用于获取Resource中的资源（当然由于当前并非IOS应用没有程序包，只是表示当前程序运行路径）
//在ios中经常用于读取应用程序中的资源文件，如图片、声音、视频等
void test7(){
    //在程序包所在目录创建一个文件
    NSFileManager *manager=[NSFileManager defaultManager];
    NSString *currentPath=[manager currentDirectoryPath];
    NSLog(@"current path is :%@",currentPath);
    //结果：current path is :/Users/kenshincui/Library/Developer/Xcode/DerivedData/FoundationFramework-awxjohcpgsqcpsanqofqogwbqgbx/Build/Products/Debug
    NSString *filePath=[currentPath stringByAppendingPathComponent:@"test.txt"];
    [manager createFileAtPath:filePath contents:[@"Hello,world!" dataUsingEncoding:NSUTF8StringEncoding] attributes:nil];
    
    
    //利用NSBundle在程序包所在目录查找对应的文件
    NSBundle *bundle=[NSBundle mainBundle];//主要操作程序包所在目录
    //如果有test.txt则返回路径，否则返回nil
    NSString *path=[bundle pathForResource:@"test" ofType:@"txt"];//也可以写成：[bundle pathForResource:@"instructions.txt" ofType:nil];
    NSLog(@"%@",path);
    //结果：/Users/kenshincui/Library/Developer/Xcode/DerivedData/FoundationFramework-awxjohcpgsqcpsanqofqogwbqgbx/Build/Products/Debug/test.txt
    NSLog(@"%@",[NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil]);
    //结果：Hello,world!
    
    //假设我们在程序运行创建一个Resources目录，并且其中新建pic.jpg，那么用下面的方法获得这个文件完整路径
    NSString *path1= [bundle pathForResource:@"pic" ofType:@"jpg" inDirectory:@"Resources"];
    NSLog(@"%@",path1);
    //结果：/Users/kenshincui/Library/Developer/Xcode/DerivedData/FoundationFramework-awxjohcpgsqcpsanqofqogwbqgbx/Build/Products/Debug/Resources/pic.jpg
}

int main(int argc,char *argv[]){

    test1();
    test2();
    test3();
    test4();
    test5();
    test6();
    test7();
    
    return 0;
}