jQuery ajax将jpg图像发布到.net webservice。图像结果已损坏

时间:2012-03-30 23:27:48

标签: jquery .net ajax rest cordova

我有一个phonegap jquery应用程序可以打开相机并拍照。

然后我把这张照片发布到.net网络服务,我编码了。

我不能使用phonegap FileTransfer,因为Bada os不支持这样做,这是一个要求。

我已成功从phonegap FileSystem API加载图像,我已将其附加到.ajax类型:post,我甚至从.net端收到它,但是当.net将图像保存到服务器中时,图像结果已损坏

- >>它是一个正确的Base64编码文件,但有这个标题“data:image / jpeg; base64,/ 9j / 4AAQ ..... =”

如何摆脱这个标题?我应该从.net还是从ajax修剪它?

任何帮助将不胜感激。

这是我的代码:

//PHONEGAP CAMERA ACCESS (summed up)
navigator.camera.getPicture(onGetPictureSuccess, onGetPictureFail, { quality: 50, destinationType:Camera.DestinationType.FILE_URI });
window.resolveLocalFileSystemURI(imageURI, onResolveFileSystemURISuccess, onResolveFileSystemURIError);
fileEntry.file(gotFileSuccess, gotFileError);
new FileReader().readAsDataURL(file);


//UPLOAD FILE
function onDataReadSuccess(evt) {
        var image_data = evt.target.result;
        var filename = unique_id();
        var filext = "jpg";

         $.ajax({
                type : 'POST',
                url : SERVICE_BASE_URL+"/fotos/"+filename+"?ext="+filext,   
                cache: false, 
                timeout: 100000, 
                processData: false, 
                data: image_data, 
                contentType: 'image/jpeg',
                success : function(data) {

                            console.log("Data Uploaded with success. Message: "+ data);
                            $.mobile.hidePageLoadingMsg();
                            $.mobile.changePage("ok.html");
                       }
                       });
            }

在我的.net Web服务上,这是被调用的方法:

public string FotoSave(string filename, string extension, Stream fileContent)
{
   string filePath = HttpContext.Current.Server.MapPath("~/foto_data/") + "\\" + filename;
   FileStream writeStream = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.Write);
   int Length = 256;
   Byte[] buffer = new Byte[Length];
   int bytesRead = readStream.Read(buffer, 0, Length);
   // write the required bytes
   while (bytesRead > 0)
   {
      writeStream.Write(buffer, 0, bytesRead);
      bytesRead = readStream.Read(buffer, 0, Length);
   }
   readStream.Close();
   writeStream.Close();
 }

1 个答案:

答案 0 :(得分:1)

好的,我明白了。问题是当我们使用$ .ajax()时,结果必须作为文本放入html中,所以例如你可以把它直接放到标签中

<textarea> background-image: data:data:image/jpeg;base64,/9j/4AAQ.....=</textarea>

但是当你尝试Convert.FromBase64String(thestring)时甚至.net告诉你“Base64字符串中的无效字符”。

总之,保留$ .ajax原样,我用这种方式修改了.net函数:

 //Convert input stream into string
 StreamReader postReader = new StreamReader(inputStreamFromWebService);
 string base64String = postReader.ReadToEnd();
 if (base64String.StartsWith("data:"))
 {
            //remove unwanted ajax header
            int indexOfBase64String = base64String.IndexOf(",") + 1;
            int lenghtOfBase64String = base64String.Length - indexOfBase64String;
            base64String = base64String.Substring(indexOfBase64String, lenghtOfBase64String);
  }

  //Convert from base64 string to byte[]
  byte[] byteFromString;
  byteFromString = Convert.FromBase64String(base64String);
  MemoryStream stream = new MemoryStream(byteFromString);

  System.IO.FileStream outFile;
  outFile = new System.IO.FileStream(filePath, System.IO.FileMode.Create, System.IO.FileAccess.Write);
  outFile.Write(byteFromString, 0, byteFromString.Length);
  outFile.Close();