NSURLConnection的异步请求方式

iOS5.0 SDK NSURLConnection类新增的sendAsynchronousRequest:queue:completionHandler:方法

sendAsynchronousRequest可以很容易地使用NSURLRequest接收回调，完成http通信。

1. post数据

- (void)httpAsynchronousRequest{

    NSURL *url = [NSURL URLWithString:@"http://url"];
    
    NSString *post=@"postData";
    
    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setHTTPMethod:@"POST"];
    [request setHTTPBody:postData];
    [request setTimeoutInterval:10.0];
    
    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    [NSURLConnection sendAsynchronousRequest:request
                                       queue:queue
                           completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
                               if (error) {
                                   NSLog(@"Httperror:%@%d", error.localizedDescription,error.code);
                               }else{
                                   
                                   NSInteger responseCode = [(NSHTTPURLResponse *)response statusCode];
                                   
                                   NSString *responseString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
                                   
                                   NSLog(@"HttpResponseCode:%d", responseCode);
                                   NSLog(@"HttpResponseBody %@",responseString);
                               }
                           }];

    
}

2. 拉取图片

        [NSURLConnection sendAsynchronousRequest:
         [NSMutableURLRequest requestWithURL:[NSURL URLWithString:imageStr]]
                                       queue:[NSOperationQueue mainQueue]
                           completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
        {
                           NSInteger responseCode = [(NSHTTPURLResponse *)response statusCode];
                           if (!error && responseCode == 200) {
                              
                               UIImage *_img = [[UIImage alloc] initWithData:data];
                               
                           }else{
                               // placeHolder image  
                           }
        }];