小字节[]块导致图像损坏

我试图将文件复制到小块大小的web处理程序。当缓冲区相对较大时总是可以正常工作，并且总是处于图像大小的时候。但是我得到的图像块大小变形太小。小字节[]块导致图像损坏

为什么，当我“M重新把相同的字节重新走到一起变化？

OpenFileDialog o = new OpenFileDialog(); 
o.ShowDialog(); 

using (WebClient webClient = new WebClient()) 
{ 
    int index = 0; 
    var tmpName = Guid.NewGuid().ToString(); 
    const int chunkSize = 10*1024; 

    webClient.Headers.Add("Filename", ""); 

    using (var file = o.OpenFile()) 
    { 

     int bytesRead; 
     //Using ChunkSize will give image distortion. But file.length works. So does dividing by 10 to result in 10 chunks. Why? 
     byte[] buffer = new byte[file.Length/10]; 

     int position = 0; 
     while (position < file.Length) 
     { 
      if (position + buffer.Length > file.Length) 
      { 
       buffer = new byte[file.Length - position]; 
      } 
      bytesRead = file.Read(buffer, 0, buffer.Length); 

      position += bytesRead; 

      var fileName = string.Format("{0}.{1}.{2}", tmpName, index, o.SafeFileName); 
      webClient.Headers["Filename"] = fileName; 
      //webClient.Headers["blockSize"] = buffer.Length.ToString(); 
      webClient.UploadData("http://localhost:49815/FileUpload.ashx", buffer); 
      index++; 

     } 

    } 
    var values = new NameValueCollection(); 
    values.Add("Filename", string.Format("{0}.{1}", tmpName, o.SafeFileName)); 
    values.Add("Complete", "true"); 
    webClient.Headers.Clear(); 
    webClient.UploadValues("http://localhost:49815/FileUpload.ashx", values); 



}

我测试

如果我不传递给块到fileupload.ashx，并把这些块重新放回到客户端应用程序中，它工作正常。
文件大小与服务器端完全匹配

同样的问题发生时将分解的文件保存到相同的位置。所以HTTP与它无关。

private void CombineFiles(string filename) 
{ 
    var fileguid = filename.Substring(0, filename.IndexOf(".") + 1); 
    var shortFileName = filename.Replace(fileguid, ""); 

    var files = Directory.GetFiles(AppDomain.CurrentDomain.BaseDirectory + "images", fileguid + "*"); 
    using (var filestream = File.Create(AppDomain.CurrentDomain.BaseDirectory + "images/" + shortFileName)) 
    { 
     foreach (string file in files) 
     { 
      var fileBuffer = File.ReadAllBytes(file); 
      filestream.Write(fileBuffer, 0, fileBuffer.Length); 
      File.Delete(file); 

     } 
    } 
}

来源

2013-06-06 Jonathan Sheely

啊。愚蠢的问题。文件乱序，因为我的命名方案是1,2,3,4,5,6,7,8,9,10。因此，当它达到10的值是1,10,2,3,4 ...

var directory = new DirectoryInfo(AppDomain.CurrentDomain.BaseDirectory + "images"); 
var files = directory.GetFiles(fileguid + "*").OrderBy(x => x.CreationTime).ToArray();

愚蠢的错误。

来源

2013-06-06 16:10:55

小字节[]块导致图像损坏

回答

相关问题