[英]Completion Handler Error in Swift
我正在嘗試使用Swift中的完成處理程序來創建自己的方法:
func callURL(url: NSURL, username: String, password: String, completionHandler: (NSData?) -> ()?) {
let request = NSMutableURLRequest(URL: url)
let un = username
let pass = password
let loginString = NSString(format: "%@:%@", un, pass)
let loginData: NSData = loginString.dataUsingEncoding(NSUTF8StringEncoding)!
let base64LoginString = loginData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(0))
request.setValue("Basic \(base64LoginString)", forHTTPHeaderField: "Authorization")
completionHandler(NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue()) {(response, data, error) in
return data
})
}
但是在完成處理程序行上出現錯誤:
'Void' is not convertible to 'NSData'
您正在通過返回Void
的函數(NSURLConnection回調)中返回NSData
。
您應該像這樣在NSURLConnection回調中調用completionHandler:
func callURL(url: NSURL, username: String, password: String, completionHandler: ((NSData?) -> Void)?) {
let request = NSMutableURLRequest(URL: url)
let un = username
let pass = password
let loginString = NSString(format: "%@:%@", un, pass)
let loginData: NSData = loginString.dataUsingEncoding(NSUTF8StringEncoding)!
let base64LoginString = loginData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(0))
request.setValue("Basic \(base64LoginString)", forHTTPHeaderField: "Authorization")
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue()) {
response, data, error in
if let completion = completionHandler {
completion(data)
}
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.