對圖元文件使用Graphic.DrawLines（Pen pen，Points points），當點數很大時圖片無法打開

我有一個GDI +圖元文件出現問題。我想通過圖形保存圖元文件。當點數爲10000並且保存的圖元文件可以打開時，它運行良好。但是，當點數很大（例如count = 10000000）時，mspaint.exe無法打開圖元文件。對圖元文件使用Graphic.DrawLines（Pen pen，Points points），當點數很大時圖片無法打開

有什麼我錯過了嗎？元文件記錄大小是否有限？順便說一句，drawrectangles也有這個問題。

這裏是我的代碼：

private void button1_Click(object sender, EventArgs e) 
{ 
    int width = 1489; 
    int height = 471; 

    Graphics offScreenBufferGraphics; 
    Metafile m; 
    using (MemoryStream stream = new MemoryStream()) 
    { 
     using (offScreenBufferGraphics = Graphics.FromHwndInternal(IntPtr.Zero)) 
     { 
      IntPtr deviceContextHandle = offScreenBufferGraphics.GetHdc(); 
      m = new Metafile(
      stream, 
      deviceContextHandle, 
      new RectangleF(0, 0, width, height), 
      MetafileFrameUnit.Pixel, 
      EmfType.EmfPlusOnly); 
      offScreenBufferGraphics.ReleaseHdc(); 
     } 
    } 

    using (Graphics g = Graphics.FromImage(m)) 
    { 
     // Set everything to high quality 
     g.SmoothingMode = SmoothingMode.HighQuality; 
     g.InterpolationMode = InterpolationMode.HighQualityBicubic; 
     g.PixelOffsetMode = PixelOffsetMode.HighQuality; 
     g.CompositingQuality = CompositingQuality.HighQuality; 

     MetafileHeader metafileHeader = m.GetMetafileHeader(); 
     g.ScaleTransform(
      metafileHeader.DpiX/g.DpiX, 
      metafileHeader.DpiY/g.DpiY); 

     g.PageUnit = GraphicsUnit.Pixel; 
     g.SetClip(new RectangleF(0, 0, width, height)); 

     // clears the image and colors the entire background 
     g.Clear(Color.White); 

     // draw lines 
     using (Pen pen = new Pen(Color.Black, 1f)) 
     { 
      Random rnd = new Random(DateTime.Now.Millisecond); 
      List<PointF> polyPoints = new List<PointF>(); 
      const int count = 10000; 
      for (int i = 1; i <= 10000000; i++) 
      { 
       polyPoints.Add(new PointF(rnd.Next(1000),rnd.Next(1000))); 
      } 
      g.DrawLines(pen, polyPoints.ToArray()); 
      // while 
     } // using 
    } // using 

    // Get a handle to the metafile 
    IntPtr iptrMetafileHandle = m.GetHenhmetafile(); 

    // Export metafile to an image file 
    CopyEnhMetaFile(iptrMetafileHandle, @"F:\CacheToDisk\test2.emf"); 

    // Delete the metafile from memory 
    DeleteEnhMetaFile(iptrMetafileHandle); 
} 

[DllImport("gdi32.dll")] 
static extern IntPtr CopyEnhMetaFile( // Copy EMF to file 
    IntPtr hemfSrc, // Handle to EMF 
    String lpszFile // File 
); 

[DllImport("gdi32.dll")] 
static extern int DeleteEnhMetaFile( // Delete EMF 
    IntPtr hemf // Handle to EMF 
);

來源

2014-02-17 user3251375

好像限制。如果我使用DrawPath而不是DrawLines，它工作正常。

來源

2014-04-02 13:11:19 user3251375

對圖元文件使用Graphic.DrawLines（Pen pen，Points points），當點數很大時圖片無法打開

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