ios - 将 UIImage 编码为 Base64 字符串在传输到服务器时不起作用

Question

将 UIImage 编码为 Base64 字符串可以在设备上工作，但将字符串传输到服务器会以某种方式损坏字符串并阻止服务器成功解码图像。

对这个问题有什么建议吗？

        // Define params
        params["thumbnail_base64"] = imageToBase64(blockSet.thumbnailURL)
        ...

        // Convert params -> query string
        let postString = buildQueryString(params)

        // Define upload URL
        let uploadURL = NSURL(string: RootURL + UploadFilePath)!

        // Hit server
        let request = NSMutableURLRequest(URL: uploadURL)
        request.HTTPMethod = "POST"
        request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
        ...

private func buildQueryString(parameters: [String:String], omitQuestionMark: Bool = false) -> String {
    var urlVars = [String]()
    for (k, var v) in parameters {
        v = v.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!
        urlVars += [k + "=" + "\(v)"]
    }
    return ((urlVars.isEmpty || omitQuestionMark) ? "" : "?") + urlVars.joinWithSeparator("&")
}


private func imageToBase64(filename: String) -> String {
    // Get image path
    let imagePath = getFilePath(filename)

    // Convert image to base64 or return empty string
    if let imageData = NSData(contentsOfFile: imagePath) {
        let base64String = imageData.base64EncodedStringWithOptions(.EncodingEndLineWithLineFeed)
        return base64String
    } else {
        printError("Error converting image to Base64: missing image. Filename: \(filename)")
        return ""
    }
}

Answer 1

问题在于 queryString，base64 是包含许多字符的长文本，让 JSON 为您完成工作

使用下一个(带有 NodeJS 的一些示例)

  let params = NSMutableDictionary();
  //you can only set `serializable` values
  params.setValue(imageToBase64(),forKey:"base64")
  params.setValue(username,forKey:"username")
  params.setValue(["array","of","string"],forKey:"arr")

  let uploadURL = NSURL(string: theURL)!

  // Hit server
  let request = NSMutableURLRequest(URL: uploadURL)
  request.HTTPMethod = "POST"

  request.setValue("application/json", forHTTPHeaderField: "Content-Type")

  do {
      let jsonData = try NSJSONSerialization.dataWithJSONObject(params, options: NSJSONWritingOptions(rawValue: 0))
      request.HTTPBody = jsonData
      let session = NSURLSession.sharedSession()

      session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
          print("Response: \(response)")
      }).resume()


  } catch let error as NSError {
      print(error)
  }

节点:

var buffer = new Buffer(request.body["base64"], 'base64')
fs.writeFile('test.jpeg',buffer,"base64"); //Works
var username = request.body["username"];
var someStringsArr  = request.body["arr"]

顺便说一下...

您编写了函数buildQueryString，该函数已存在于Foundation中

let urlComponents = NSURLComponents(string: "http://myUrl.com/getApi/")!
urlComponents.queryItems = [NSURLQueryItem]()
urlComponents.queryItems!.append(NSURLQueryItem(name:"myKeyA",value:"myValueA"))
urlComponents.queryItems!.append(NSURLQueryItem(name:"myKeyB",value:"myValueB"))

print(urlComponents.URL!) //http://myUrl.com/getApi/?myKeyA=myValueA&myKeyB=myValueB

如果想通过URL发送GET参数，请使用url查询