post

   
    NSURL *url = [NSURL URLWithString:@"https://www.baidu.com"];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    request.HTTPMethod = @"POST";

　　// 请求参数
    NSString *bodyStr = [NSString stringWithFormat:@"username=%@&password=%@", username, password];

    request.HTTPBody = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];

    NSData *data =[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

    NSError *error = nil;

    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];

    NSLog(@"---------------%@", json);