iOS 开发笔记-NSURLConnection的使用

//send a GET request to server with some params
-(void)httpGetWithParams{
    NSString *urlString = @"http://chaoyuan.sinaapp.com";
    urlString = [urlString stringByAppendingString:@"?p=1059"];
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];
    [urlRequest setTimeoutInterval:30.0f];
    [urlRequest setHTTPMethod:@"GET"];
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        if ([data length] > 0 && connectionError == nil) {
            NSString *html = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
            NSLog(@"HTML = %@",html);
        }else if([data length] == 0 && connectionError == nil){
            NSLog(@"nothing was download.");
        }else if(connectionError != nil){
            NSLog(@"Error happened = %@",connectionError);
        }
    }];
}

//send a POST request to a server with some params
-(void)httpPostWithParams{
    NSString *urlAsString = @"http://chaoyuan.sinaapp.com";
    urlAsString = [urlAsString stringByAppendingString:@"?param1=First"];
    urlAsString = [urlAsString stringByAppendingString:@"¶m2=Second"];
    NSURL *url = [NSURL URLWithString:urlAsString];
    NSString *body = @"bodyParam1=BodyValue1&bodyParam2=BodyValue2";
    NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];
    [urlRequest setTimeoutInterval:30.0f];
    [urlRequest setHTTPMethod:@"POST"];
    [urlRequest setHTTPBody:[body dataUsingEncoding:NSUTF8StringEncoding]];
    [urlRequest setValue:[NSString stringWithFormat:@"%lu", (unsigned long)[body length]] forHTTPHeaderField:@"Content-Length"];
    [urlRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [NSURLConnection
     sendAsynchronousRequest:urlRequest
     queue:queue completionHandler:^(NSURLResponse *response, NSData *data,
                                     NSError *error) {
         if ([data length] >0 &&
             error == nil){
             NSString *html = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]; NSLog(@"HTML = %@", html);
             // 显示到UIWebView
             //[self.bankWebView loadData:data MIMEType:@"text/html" textEncodingName:@"UTF-8" baseURL:nil];
         }
         else if ([data length] == 0 &&
                  error == nil){
             NSLog(@"Nothing was downloaded.");
         }
         else if (error != nil){
             NSLog(@"Error happened = %@", error);
         }
     }];
}