UI 网络请求（同步GET，同步POST，异步GET，异步POST）具体操作

本文链接：https://blog.youkuaiyun.com/u012225356/article/details/34950151
#import "MainViewController.h"

@interface MainViewController ()<NSURLConnectionDataDelegate>

@property (nonatomic, retain)UIImageView *imageView;

@property (nonatomic, retain)NSMutableData *data;// 可变数据 Data 用于拼接每次接受来的数据块
@end

@implementation MainViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 20, 280, 280)];
    self.imageView.backgroundColor = [UIColor redColor];
    [self.view addSubview:self.imageView];
    [self.imageView release];
    
    UIButton *button1 = [UIButton buttonWithType:UIButtonTypeSystem];
    button1.frame = CGRectMake(20, 320, 120, 40);
    button1.backgroundColor = [UIColor brownColor];
    [button1 setTitle:@"同步 GET" forState:UIControlStateNormal];
    [button1 addTarget:self action:@selector(buttonClicked1:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button1];
    
    
    UIButton *button2 = [UIButton buttonWithType:UIButtonTypeSystem];
    button2.frame = CGRectMake(180, 320, 120, 40);
    button2.backgroundColor = [UIColor brownColor];
    [button2 setTitle:@"同步 POST" forState:UIControlStateNormal];
    [button2 addTarget:self action:@selector(buttonClicked2:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button2];
    
    
    UIButton *button3 = [UIButton buttonWithType:UIButtonTypeSystem];
    button3.frame = CGRectMake(20, 400, 120, 40);
    button3.backgroundColor = [UIColor brownColor];
    [button3 setTitle:@"异步 GET" forState:UIControlStateNormal];
    [button3 addTarget:self action:@selector(buttonClicked3:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button3];
    
    
    UIButton *button4 = [UIButton buttonWithType:UIButtonTypeSystem];
    button4.frame = CGRectMake(180, 400, 120, 40);
    button4.backgroundColor = [UIColor brownColor];
    [button4 setTitle:@"异步 POST" forState:UIControlStateNormal];
    [button4 addTarget:self action:@selector(buttonClicked4:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button4];
    
}

- (void)buttonClicked1:(UIButton *)button
{
    // 同步GET
    // 1.拼接网络地址
    NSString *str  = @"http://cdn.gq.com.tw.s3-ap-northeast-1.amazonaws.com/userfiles/images_A1/6954/2011100658141857.jpg"
    ;
    // 2.将地址转化为URL对象
    NSURL *url = [NSURL URLWithString:str];
    
    // 3. 创建一个请求（request）
    // 参数1： 请求地址（NSURL）
    // 参数2：给请求选择一个缓存策略
    // 参数3: 请求超时时间
    NSMutableURLRequest *requset = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:30.0];
    // 4. 给请求设置 请求方式
    [requset setHTTPMethod:@"GET"];
    // 5. 将请求发送给服务器
    
    // 同步连接
    // 参数1：请求（request）
    // 参数2：响应信息
    // 参数3：错误信息
    // 同步连接的方法 会一直等待 数据完整接受之后才继续执行
    NSURLResponse *response = nil;
    NSError *error = nil;
    NSData *data = [NSURLConnection sendSynchronousRequest:requset returningResponse:&response error:&error];
    
    //在这里获得的是完整的 data数据
    NSLog(@"服务器响应信息：%@", response);
    
    // 使用NSData数据
    UIImage *image = [UIImage imageWithData:data];
    self.imageView.image = image;
    NSLog(@"%@", NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES));

}
-(void)dealloc
{
    [_data release];
    [_imageView release];
    [super dealloc];
}
- (void)buttonClicked2:(UIButton *)button
{
    // 同步POST
    NSString *str = @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx";
    NSURL *url = [NSURL URLWithString:str];
    
    // 创建请求
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    // 设置请求方式
    [request setHTTPMethod:@"POST"];
    
    // 产生一个body
    NSString *bodyStr = @"date=20131129&startRecord=1&len=30&udid=1234567890&terminalType=Iphone&cid=213";
    NSData *data = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];
    
    // 设置post请求 附带的数据
    [request setHTTPBody:data];
    
    // 同步连接 获取内容
    NSURLResponse *response = nil;
    NSData *dataBack = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSLog(@"%@", response);
    
    // 测试返回数据内容
    NSString *result = [[NSString alloc] initWithData:dataBack encoding:NSUTF8StringEncoding];
    NSLog(@"%@", result);

}

- (void)buttonClicked3:(UIButton *)button
{
    // 异步
    // 1. 产生请求
    NSString *str = @"http://pic13.nipic.com/20110313/2686941_211532129160_2.jpg";
    NSURL *url = [NSURL URLWithString:str];
    
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    
    [request setHTTPMethod:@"GET"];
    
    // 2.建立连接
    // 异步联接 不会卡死界面
    // 参数1:设定好的请求
    // 参数2：设定网络请求的代理人
    [NSURLConnection connectionWithRequest:request delegate:self];
    
    
}
// 当收到服务器的响应信息 的时候 调用
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    // 当每次需要接受新的数据的时候 初始化data属性
    NSLog(@"%s", __FUNCTION__);
    self.data = [NSMutableData data];
}
// 当收到服务器发送来的 data数据块 的时候 调用
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    NSLog(@"%s", __FUNCTION__);
    [self.data appendData:data];
}
// 当数据接受完毕 的时候 调用
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    // 调用这个方法 说明 self.data属性已经是一个完整的数据
    NSLog(@"%s", __FUNCTION__);
    UIImage *image = [UIImage imageWithData:self.data];
    self.imageView.image = image;
}
- (void)buttonClicked4:(UIButton *)button
{
    // 异步POST

    NSString *str = @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx";
    NSURL *url = [NSURL URLWithString:str];
    
    // 创建请求
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    // 设置请求方式
    [request setHTTPMethod:@"POST"];
    
    // 设置body
    NSString *bodyStr = @"date=20131129&startRecord=1&len=30&udid=1234567890&terminalType=Iphone&cid=213";
    NSData *data = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];
    
    // 设置post请求 附带的数据
    [request setHTTPBody:data];
    
    
    
    // 2. 连接
    // block 基础上的异步连接
    
    
    // 参数1：请求
    // 参数2：返回主线程
    // 参数3：
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        // 当异步联接完毕 而且 请求但完整的数据（参数data）之后 才执行这个块的内容
        
        // 在这个块中 写处理数据的代码 （解析/转化为image/音频/视频）
        NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
        NSLog(@"%@", dic);
    }];
    
}