C# winform 打印当前窗体

要打印当前窗体，可以使用C#的PrintDocument类和PrintPreviewDialog类来实现。以下是实现的步骤：

1. 创建一个PrintDocument类的实例，并设置它的PrintPage事件处理程序。

PrintDocument printDocument = new PrintDocument();
printDocument.PrintPage += new PrintPageEventHandler(PrintPage);

2. 在PrintPage事件处理程序中，使用Graphics类的DrawImage方法将当前窗体的内容绘制到打印页面上。

private void PrintPage(object sender, PrintPageEventArgs e)
{
    Bitmap bitmap = new Bitmap(this.Width, this.Height);
    this.DrawToBitmap(bitmap, new Rectangle(0, 0, this.Width, this.Height));
    e.Graphics.DrawImage(bitmap, e.MarginBounds);
}

3. 创建一个PrintPreviewDialog类的实例，并将前面创建的PrintDocument类实例赋给它的Document属性。

PrintPreviewDialog printPreviewDialog = new PrintPreviewDialog();
printPreviewDialog.Document = printDocument;

4. 调用PrintPreviewDialog类的ShowDialog方法来显示打印预览对话框。

printPreviewDialog.ShowDialog();

完整的代码示例：

private void buttonPrint_Click(object sender, EventArgs e)
{
    PrintDocument printDocument = new PrintDocument();
    printDocument.PrintPage += new PrintPageEventHandler(PrintPage);

    PrintPreviewDialog printPreviewDialog = new PrintPreviewDialog();
    printPreviewDialog.Document = printDocument;

    printPreviewDialog.ShowDialog();
}

private void PrintPage(object sender, PrintPageEventArgs e)
{
    Bitmap bitmap = new Bitmap(this.Width, this.Height);
    this.DrawToBitmap(bitmap, new Rectangle(0, 0, this.Width, this.Height));
    e.Graphics.DrawImage(bitmap, e.MarginBounds);
}