Spread 表格控件支持打印到 PDF 文件，通过 PrintInfo 类下的 PrintToPdf 方法可以实现打印 PDF 功能。
最近，有用户询问如何打印带有背景图的PDF文件。虽然，Spread 不内置该功能，但是我们可以同过自定义来实现。
实现方法很简单，设置 Spread 的背景色为透明色，此时Spread的背景图即可见。
详细请参考代码：
1: private void fpSpread1_PrintBackground(object sender, FarPoint.Win.Spread.PrintBackgroundEventArgs e)
2: {
3: System.Drawing.Drawing2D.GraphicsState saveState = e.Graphics.Save();
4: Rectangle rect = e.SheetRectangle;
5: rect.Width = (int)AdjustWorkaroundForPDFPrint((float)rect.Width);
6: rect.Height = (int)AdjustWorkaroundForPDFPrint((float)rect.Height);
7: e.Graphics.SetClip(rect);
8: e.Graphics.SetClip(rect);
9: e.Graphics.DrawImage(fpSpread1.BackgroundImage, rect);
10: e.Graphics.Restore(saveState);
11: }
12: private float AdjustWorkaroundForPDFPrint(float value)
13: {
14: float _ptperInch = 72;
15: //Points Per inch
16: float pixelPointFactor = (float)(_ptperInch / 96);
17: //pixel point factor base on graphic dpi
18: float displayPointFactor = (float)(_ptperInch / 100);
19: //point factor base on display graphic unit
20: return (float)(value * displayPointFactor / pixelPointFactor);
21: }
Demo 下载：VS2010 + C# + Spread Studio 7 + .NET 4.0: 点击下载
Demo 下载：VS2010 + VB.NET + Spread Studio 7 + .NET 4.0: 点击下载
