如何替換被同一進程鎖定的文件？

Question

我正在嘗試調整圖像大小。首先，我讀的圖像轉換爲字節數組，調整它在內存中，並把它寫回同一個文件：

public static void CropAndResizeImage(EntryImage image, int left, int top, int right, int bottom) 
    { 
     Size newSize = new Size(); 
     string imagePathAndFilename = HttpContext.Current.Server.MapPath(image.URL); 

     //byte[] photoBytes = File.ReadAllBytes(imagePathAndFilename); 
     using (FileStream fs = new FileStream(imagePathAndFilename, FileMode.Open, FileAccess.ReadWrite)) 
     { 
      fs.Position = 0; 
      var photoBytes = new byte[fs.Length]; 
      int read = fs.Read(photoBytes, 0, photoBytes.Length); 

      // Process photo and resize 
      using (MemoryStream inStream = new MemoryStream(photoBytes)) 
      using (MemoryStream outStream = new MemoryStream()) 
      { 
       using (ImageFactory imageFactory = new ImageFactory(preserveExifData: true))// Initialize the ImageFactory using the overload to preserve EXIF metadata. 
       { 

        ISupportedImageFormat format = new JpegFormat { Quality = 75 }; // Format is automatically detected though can be changed. 
        Size maxSize = new Size(1024, 1024); 
        ResizeLayer layer = new ResizeLayer(maxSize, upscale: false, resizeMode: ResizeMode.Max); 
        layer.Upscale = false; 

        // Load, resize, set the format and quality and save an image. 
        imageFactory.Load(inStream) 
           .Crop(new CropLayer(left, top, right - left, bottom - top, CropMode.Pixels)) // Crop is relative to image edge, not absolute coords. 
           .Resize(layer) 
           .Format(format) 
           .Save(outStream); 

        newSize.Width = imageFactory.Image.Width; 
        newSize.Height = imageFactory.Image.Height; 
       } 

       // Write back to the same file 
       fs.Position = 0; 
       fs.SetLength(photoBytes.Length); 
       fs.Write(photoBytes, 0, photoBytes.Length); 
      } 
     } 
    } 

但是通常出現以下錯誤：

The process cannot access the file: 'C:\folder\image.jpg' because it is being used by another process.

這是爲什麼？我會假定File.ReadAllBytes（）會自動關閉文件？

Process Explorer中的文件沒有文件句柄或鎖（這看起來很奇怪）。

即使我在while循環增加一些延遲，循環永遠不會結束，這意味着該文件將被永久鎖定：

bool saved = false; 
while (!saved) 
{ 
    try 
    { 
     SaveImageToFile(imagePathAndFilename, outStream); 
     saved = true; 
    } 
    catch (IOException ex) 
    { 
     System.Threading.Thread.Sleep(1000); 
    } 
} 

編輯：更新，以顯示完整的代碼並納入技工的回答了我的代碼上面來展示我的實現。

Answer 1

而不是讀取所有字節你可以使用FileStream並保持文件上的保留？很抱歉，如果這個代碼是不準確的，你可能需要，如果你的文件長度縮短使用fs.SetLength功能

using (FileStream fs = new FileStream(imagePathAndFilename, FileMode.Open, FileAccess.ReadWrite)) 
{ 
    fs.Position = 0; 
    var buffer = new byte[fs.Length]; 
    int read = fs.Read(buffer, 0, buffer.Length); 

    // Manipulate bytes here 

    fs.Position = 0; 
    fs.SetLength(buffer.Length); 
    fs.Write(buffer, 0, buffer.Length); 
} 

編輯修剪訪問字節：增加了SetLength改變流大小