致命错误error Domain=NSCocoaErrorDomain Code=3840“在swift中上载图像时，字符0周围的值无效

Question

我正在尝试将图像上载到服务器，它工作正常，但偶尔我会在下面的代码中收到try语句错误。这就是错误所说的

致命错误：“try！”表达式意外引发错误：错误域 = NSCocoa错误域代码 = 3840 “字符 0 周围的无效值”。用户信息={NSDebug 说明= 字符 0.} 周围的无效值：文件/库/缓存/com.apple.xbs/源/swiftlang_PONDEROSA/swiftlang_PONDEROSA-700.1.101.6/src/swift/stdlib/公共/核心/错误类型.swift，第 50 行

 func uploadImages(imageData: NSData, withParams requestDict:NSDictionary, callBack:(responseDict: NSDictionary?, error: NSError?) -> ())
    {

        print(requestDict)
        let boundary = generateBoundaryString()

        let url:NSURL = NSURL(string: String(format: "%@%@", BASE_URL, IMAGE_UPLOAD_API))!
        let request = NSMutableURLRequest(URL: url)
        request.HTTPMethod = "POST"
        request.timeoutInterval          = FLOAT_CONSTANT_60
        request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

        request.HTTPBody = createBodyWithParameters(requestDict as? [String : AnyObject], filePathKey: "image", imageData: imageData, boundary: boundary)

        print(requestDict)
        NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler:{ (response: NSURLResponse?, data: NSData?, error: NSError?) in
            do {
                let JSON = try! NSJSONSerialization.JSONObjectWithData(data!, options:NSJSONReadingOptions.AllowFragments)
                guard let JSONDictionary :NSDictionary = JSON as? NSDictionary else {
                    print("Not a Dictionary")
                    //get your JSONData here from dictionary.

                    return
                }
                callBack(responseDict: JSON as? NSDictionary, error: nil)
                print("JSONDictionary! \(JSONDictionary)")

            }
            catch let JSONError as NSError {
                print("\(JSONError)")
                callBack(responseDict: nil, error: JSONError)

            }

        })

     }

Answer 1

由于我使用的API返回的json数据前面的一些无效字符/填充，我遇到了类似的问题。为了修复它，我必须在试图反序列化它之前去掉前几个字符。

var parsedDictionary: NSDictionary? = nil;
do{
   let loginResult = result.subdataWithRange(NSMakeRange(5, result.length - 5))
 parsedDictionary = try! NSJSONSerialization.JSONObjectWithData(loginResult, options: .AllowFragments) as? NSDictionary;
}

希望这有所帮助。