如何提出jsonpost请求?

How to make json post request?

我必须使用以下请求参数进行 json post 请求,

{   
    "method":"login", 
    "data":{  
        "username":"korea", 
        "password":"123456" 
    } 
} 

我使用以下代码发出请求,

NSString *jsonRequest = [NSString stringWithFormat:@"{""\"\method:\"\login\"\"\,""\data:\"{\"\"username\":\"%@\",\"password\":\"%@\"}",username,password];
    NSLog(@"Request: %@", jsonRequest);

    NSURL *url = [NSURL URLWithString:@"http://myurl..."];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
    NSData *requestData = [NSData dataWithBytes:[jsonRequest UTF8String] length:[jsonRequest length]];

    [request setHTTPMethod:@"POST"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [request setValue:[NSString stringWithFormat:@"%d", [requestData length]] forHTTPHeaderField:@"Content-Length"];
    [request setHTTPBody: requestData];

    NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self];

我必须得到回应,但我无法得到回应

试试这个

    NSDictionary *objectDic = @{@"username" : username, @"password" : password};
    NSDictionary *dataDic = @{@"data" : objectDic};
    NSDictionary *methodDic = @{@"method" : @"login", @"data": dataDic};

    NSData *requestData = [NSJSONSerialization dataWithJSONObject:methodDic
                                               options:NSJSONWritingPrettyPrinted
                                                 error:nil];
    [request setHTTPBody: requestData];