在 Swift 中执行 POST 请求

我正在尝试做这样的事情：

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://google.com"]];

request.HTTPMethod = @"POST";

NSString *stringData = @"some data";
NSData *requestBodyData = [stringData dataUsingEncoding:NSUTF8StringEncoding];
request.HTTPBody = requestBodyData;

NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];

这是我到目前为止所拥有的：

var url = NSURL(string: "some url")
var request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "POST"

var dataString = "some data"
var requestBodyData: NSData = dataString.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding) as NSData

request.HTTPBody = requestBodyData

var connection = NSURLConnection(request: request, delegate: self, startImmediately: false)

println("sending request...")

connection.start()

然而， var requestBodyData: 行抛出第一块石头“无法将表达式的 NSData 类型转换为 NSData 类型”

有人愿意来衡量一下吗？

stringByAddingPercentEscapesUsingEncoding返回一个字符串而不是 NSData 对象。根据this https://stackoverflow.com/questions/24039868/creating-nsdata-from-nsstring-in-swift答案，您需要使用它来转换为 NSData 实例：

let data = (anySwiftString as NSString).dataUsingEncoding(NSUTF8StringEncoding)