C＃ - 如何打印宽高比/整页

Question

我在点击按钮时打印CHART控件：

chart1.SaveImage(ms, ChartImageFormat.Bmp);
Bitmap bm = new Bitmap(ms);

PrintDocument doc = new PrintDocument();
doc.PrintPage += (s, ev) =>
{
    ev.Graphics.DrawImage(bm, Point.Empty); // adjust this to put the image elsewhere
    ev.HasMorePages = false;
};
doc.DefaultPageSettings.Landscape = true;

doc.Print();

如何强制它打印控件以使其适合页面大小（保留纵横比）？

Answer 1

至少有两种不同的方法， 包括缩放要打印的图像以适合所选打印机的页面大小 ：

1）使用.NET工具（我自己没有测试过，从这篇帖子中取消）：

    private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
    {
        Image i = pictureBox1.Image;

        float newWidth = i.Width * 100 / i.HorizontalResolution;
        float newHeight = i.Height * 100 / i.VerticalResolution;

        float widthFactor = newWidth / e.MarginBounds.Width;
        float heightFactor = newHeight / e.MarginBounds.Height;

        if(widthFactor>1 | heightFactor > 1)
        {
            if(widthFactor > heightFactor)
            {
                newWidth = newWidth / widthFactor;
                newHeight = newHeight / widthFactor;
            }
            else
            {
                newWidth = newWidth / heightFactor;
                newHeight = newHeight / heightFactor;
            }
        }
        e.Graphics.DrawImage(i, 0, 0, (int)newWidth, (int)newHeight);
    }
}

2） P /调用来自GDI和平面GDI的Windows API调用（这更复杂但更快，你可以传递位图文件的普通字节数组（读取文件为byte []），向我发送电子邮件如果需要这个代码）：

  private static extern bool ClosePrinter(IntPtr hPrinter);
  private static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);
  private static extern int SetJob(IntPtr hPrinter, int JobId, int Level, ref byte pJob, int Command_Renamed);
  private static extern int GdiplusStartup(out IntPtr token, ref StartupInput input, out StartupOutput output);
  private static extern int GdiplusShutdown(IntPtr token);
  internal static extern int GdipLoadImageFromStream([In, MarshalAs(UnmanagedType.Interface)]IStream stream, out IntPtr image);
  internal static extern int GdipDisposeImage(IntPtr image);
  static internal extern int GdipCreateFromHDC2(IntPtr hDC, IntPtr hDevice, out IntPtr graphics);
  static internal extern int GdipDeleteGraphics(IntPtr graphics);
  static internal extern int GdipReleaseDC(IntPtr graphics, IntPtr hdc);
  internal static extern int GdipGetImageDimension(IntPtr image, out float width, out float height);
  internal static extern int GdipGetDpiX(IntPtr graphics, out float dpi);
  internal static extern int GdipGetDpiY(IntPtr graphics, out float dpi);
  static internal extern int GdipDrawImageRectI(IntPtr graphics, IntPtr image, int x, int y, int width, int height);
  private static extern IntPtr CreateDC([MarshalAs(UnmanagedType.LPStr)] string lpszDriver, [MarshalAs(UnmanagedType.LPStr)] string lpszDevice, [MarshalAs(UnmanagedType.LPStr)] string lpszOutput, IntPtr lpInitData);
  private static extern bool DeleteDC(IntPtr hdc);
  private static extern int StartDoc(IntPtr hdc, DOCINFO lpdi);
  private static extern int EndDoc(IntPtr hdc);
  private static extern int StartPage(IntPtr hdc);
  private static extern int EndPage(IntPtr hdc);
  private static extern int GetDeviceCaps(IntPtr hdc, int nIndex);

Answer 2

这就是我为实现这一目标所做的工作。 令人讨厌的是图表控件只会将其内容绘制为与屏幕大小相同的大小。 我发现解决这个问题的唯一方法是手动调整它。 然后，因为它可能不喜欢在表单上调整大小时，这也涉及暂时将其从表单中删除。

所有这些，我最终得到这样的东西：

Chart ChartBox { get; private set; }

...

var oldParent = ChartBox.Parent;
var oldSize = ChartBox.Size;

ChartBox.Parent = null;
ChartBox.Size = new Size(width, height);

ChartBox.Printing.Print();

ChartBox.Parent = oldParent;
ChartBox.Size = oldSize;

根据您的表单，您可能还需要保存和恢复图表控件的其他属性。