iOS网络-NSURLConnection简单介绍

//1.确定请求路径
    //协议头+主机地址+接口名称+?+参数1&参数2&参数3
    NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=520it&pwd=520it&type=JSON"];    
    //2.创建请求对象|GET
    //默认已经包含了请求头|请求方法(GET)
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url];  
    //3.发送请求(GET)
    //同步请求,会阻塞线程
    /*
     第一个参数:请求对象
     第二个参数:响应头
     第三个参数:错误信息
     返回值:NSData类型,响应体信息
     */
    NSError *error = nil;
    NSURLResponse *response = nil;
    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];  
    //4.解析数据
    if (error == nil) {
        NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);
        NSLog(@"%@---%@",response,error);
    }

    //1.确定请求路径
    //协议头+主机地址+接口名称+?+参数1&参数2&参数3
    NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=888&pwd=520it&type=JSON"];   
    //2.创建请求对象|GET
    //默认已经包含了请求头|请求方法(GET)
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url];    
    //3.发送异步请求
    /*
     第一个参数:请求对象
     第二个参数:队列,决定block在哪个线程调用
     第三个参数:completionHandler 当请求结束(成功|失败)的时候执行
        response:响应头
        data:响应体信息
     connectionError:错误信息
     */
    [NSURLConnection sendAs
ynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {
        //4.解析数据
        NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);
    }];

//1.确定请求路径
    NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login?username=520it&pwd=520it&type=JSON"];
    
    //2.创建请求对象
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    
    //3.设置代理
    //第一种方式,该方法会自动发送网络请求
   //NSURLConnection *connect =  [[NSURLConnection alloc]initWithRequest:request delegate:self];
    
     //第二种方式,同上
    //[NSURLConnection connectionWithRequest:request delegate:self];
    
    //第三种方法
    /*
     第一个参数:请求对象
     第二个参数:谁成为代理
     第三个参数:startImmediately :是否立即开始发送网络请求
     */
    NSURLConnection *connect = [[NSURLConnection alloc]initWithRequest:request delegate:self startImmediately:NO];
    [connect start];
    //[connect cancel]; 取消
#pragma mark - NSURLConnectionDataDelegate
//1.当接受到服务器响应的时候会调用:response(响应头)
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    self.fileData = [NSMutableData data];
    
    NSLog(@"didReceiveResponse");
}

//2.当接受到服务器返回数据的时候调用(会调用多次)
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
   NSLog(@"didReceiveData---%zd",data.length);
    
    //拼接数据
    [self.fileData appendData:data];
}

//3.当请求失败的时候调用
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"didFailWithError");
}

//4.当请求结束(成功|失败)的时候调用
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"connectionDidFinishLoading");

    //解析数据
    NSLog(@"%@",[[NSString alloc]initWithData:self.fileData encoding:NSUTF8StringEncoding]);
}

    //1.确定请求路径
    NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/login"];
    //2.创建请求对象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    //2.1更改请求方法
    request.HTTPMethod = @"POST";
    //2.2设置请求体
    request.HTTPBody = [@"username=520it&pwd=520it" dataUsingEncoding:NSUTF8StringEncoding];
    //2.3请求超时
    request.timeoutInterval = 5;
    //2.4设置请求头
    [request setValue:@"ios 9.0" forHTTPHeaderField:@"User-Agent"];
    //3.发送请求
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * __nullable response, NSData * __nullable data, NSError * __nullable connectionError) {
    //4.解析服务器返回的数据
        if (connectionError) {
            NSLog(@"--请求失败-");
        }else
        {
            NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);
        }

    }];