Question

我正在尝试将文件复制到小块大小的Web处理程序中。它在缓冲区相对较大时工作正常，并且总是在图像大小时工作。但是我得到的块大小的图像失真太小了。

当我将相同的字节重新组合在一起时，为什么会改变？

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);



}

我测试了什么

如果我没有传递给fileupload.ashx的块，只是将这些块放回到客户端应用程序上就可以正常工作了。
文件大小与服务器端完全匹配。

将分解的文件保存到同一位置会出现同样的问题。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);

        }
    }
}

Answer 1

啊。愚蠢的问题。由于我的命名方案是1,2,3,4,5,6,7,8,9,10，因此文件出现故障。因此当它达到10时，值为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。

小字节[]块会导致图像损坏

1 个答案: