由网友(撸致呻@)分享简介：我收到此异常，有时运行时，我的Windows窗体应用程序很长一段时间：I am getting this exception sometimes while running my Windows Forms app for a long time:System.ComponentModel.Win32Excepti...

我收到此异常，有时运行时，我的Windows窗体应用程序很长一段时间：

I am getting this exception sometimes while running my Windows Forms app for a long time:

System.ComponentModel.Win32Exception: The operation completed successfully
   at System.Drawing.BufferedGraphicsContext.CreateCompatibleDIB(IntPtr hdc, IntPtr hpal, Int32 ulWidth, Int32 ulHeight, IntPtr& ppvBits)
   at System.Drawing.BufferedGraphicsContext.CreateBuffer(IntPtr src, Int32 offsetX, Int32 offsetY, Int32 width, Int32 height)
   at System.Drawing.BufferedGraphicsContext.AllocBuffer(Graphics targetGraphics, IntPtr targetDC, Rectangle targetRectangle)
   at System.Drawing.BufferedGraphicsContext.AllocBufferInTempManager(Graphics targetGraphics, IntPtr targetDC, Rectangle targetRectangle)
   at System.Drawing.BufferedGraphicsContext.Allocate(IntPtr targetDC, Rectangle targetRectangle)
   at System.Windows.Forms.Control.WmPaint(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.DataGridView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

可能是什么原因呢？

What could be the cause for this?

推荐答案

只是为了概括起来讲，自定义网格我写的，是基于.NET的DataGridView中，使用自定义code绘制细胞。在我的网格行可以跨多个可视页面。 （这是一个业务需求）

Just to sum it up, the custom grid I wrote, that is based on the .Net's DataGridView, uses custom code to draw cells. Rows in my grid can span multiple visual pages. (That was a business requirement)

的问题是，净$ P $对 - 分配存储缓冲器，用于控制与DoubleBuffering启用。对于DataGridViews网格上的缓冲区需要相当大，以适应电网可能较大的行。在极端的情况下，一排可以跨越高达32000像素（因为一个.NET限制）。网格宽度在项目通常是500和800像素之间。 因此，所产生的缓冲即可（32bpp的* 800 * 32000 =〜100MB）

The problem was that .Net pre-allocates a buffer of memory for controls with DoubleBuffering enabled. For DataGridViews grids the buffer needs to be rather large to accommodate possible large rows in the grid. In extreme cases a row can span up to 32000 pixels (because of a .net limitation). Grid widths in the project are usually between 500 and 800 pixels. So the resulting buffer can be (32bpp * 800 * 32000 = ~100MB)

因此​​，在短期中，系统不能创建兼容的图形对象，因为偶尔，它不能保留的缓冲器足够大，以适应所需的数据。

So in short, the system could not create compatible graphics objects, because occasionally, it could not reserve a buffer large enough to fit the required data.

要解决它，我已经向大家介绍了一系列的优化：

To fix it I had to introduce a series of optimizations:

在我的自定义网格允许1500像素的限制最大行高 更新缓冲区重新分配code到只执行时，新缓冲区大小大于现有的 确保了缓冲区不重新分配与每一个数据绑定和preallocated到一个合理的规模。 在审查了所有code和确信，非托管资源的正确不使用时，建议在这里设置，：http://nomagichere.blogspot.com/2008/03/systemcomponentmodelwin32exception-is.html