使用 OpenTK / OpenGL，我可以在 Winforms 上进行绘制。但是我如何在打印机上绘图？
我在甘特图上工作并使用这段代码进行打印，但我不确定如何让设备上下文进入 GLControl。
private void print_click(object sender, EventArgs e)
{
dialog.Document = new PrintDocument();
using (var dialog = new PrintDialog())
{
if (dialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
dialog.Document.BeginPrint += new System.Drawing.Printing.PrintEventHandler(Document_BeginPrint);
dialog.Document.EndPrint += new System.Drawing.Printing.PrintEventHandler(Document_EndPrint);
dialog.Document.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(Document_PrintPage);
dialog.Document.Print();
}
}
}
void Document_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
// This code does not work!
// something to do with e.Graphics.GetHdc() ???
var nullWindow = OpenTK.Platform.Utilities.CreateWindowsWindowInfo(IntPtr.Zero);
// Exception of type 'OpenTK.Graphics.GraphicsContextException' was thrown.
var printcontext = new OpenTK.Graphics.GraphicsContext(new ContextHandle(e.Graphics.GetHdc()), nullWindow);
printcontext.MakeCurrent(nullWindow);
// GL.Begin(...)
// ...
// GL.End()
// printcontext.SwapBuffers()? Should be single-buffered?
}
void Document_EndPrint(object sender, System.Drawing.Printing.PrintEventArgs e)
{
}
void Document_BeginPrint(object sender, System.Drawing.Printing.PrintEventArgs e)
{
}
我还注意到了OpenTK.Graphics.GraphicsContext (ContextHandle handle, IWindowInfo window)构造函数，但我不确定要为 IWindowInfo 放置什么。