C#對被遮擋的窗體進行截圖

最近在做的一個項目，用的地圖控件比較特殊，

在地圖上面自己繪制的東東沒辦法隨地圖一起導出成圖片

只能繞個彎,用截屏的方式了
一開始用的是這樣:

1. /// <summary>
2. /// 截圖
3. /// </summary>
4. /// <returns></returns>
5. private Image CaptureScreen()
6. {
7. Image MyImage = null;
9. //獲得當前地圖控件的大小
10. Graphics grapScreen = m_pFremework.Hook.CreateGraphics();
12. //Rectangle rect = new Rectangle();
13. //rect = Screen.GetWorkingArea(m_pFremework.Hook);//范圍不准確,直接使用控件的屬性
14. Rectangle rect = new Rectangle(0, 0, m_pFremework.Hook.Width, m_pFremework.Hook.Height);
15. MyImage = new Bitmap(rect.Width, rect.Height, grapScreen);
16. Graphics grapImage = Graphics.FromImage(MyImage);
17. IntPtr dc1 = grapScreen.GetHdc();
18. IntPtr dc2 = grapImage.GetHdc();
20. BitBlt(dc2, 0, 0, rect.Width, rect.Height, dc1, 0, 0, 13369376);
22. //釋放掉DC
23. grapScreen.ReleaseHdc(dc1);
24. grapImage.ReleaseHdc(dc2);
25. return MyImage;
26. }

這個函數在win7中沒有任何問題,但在xp中發現,任何遮擋到地圖控件的窗體都被截下來了
網上搜搜,發現了一個PrintWindow API可以解決這個問題,用下來發現這個只能截整個窗體,
無法單獨截取地圖控件,這個就簡單了,直接使用BitMap的Clone函數裁剪出來地圖控件部分就搞定了,
代碼是這個樣子:

1. private Image CaptureScreen2()
2. {
3. Image MyImage = null;
4. IntPtr hdc = GetWindowDC(m_pFremework.MdiForm.Handle);
5. LPPOINT lphook = new LPPOINT();
6. lphook.x = 0;
7. lphook.y = 0;
9. ClientToScreen(m_pFremework.Hook.Handle, ref lphook);
10. ScreenToClient(m_pFremework.MdiForm.Handle, ref lphook);
11. Rectangle rect = new Rectangle(lphook.x, lphook.y, m_pFremework.Hook.Width, m_pFremework.Hook.Height);
12. if (hdc != IntPtr.Zero)
13. {
14. IntPtr hdcMem = CreateCompatibleDC(hdc);
15. if (hdcMem != IntPtr.Zero)
16. {
17. IntPtr hbitmap = CreateCompatibleBitmap(hdc, m_pFremework.MdiForm.Width, m_pFremework.MdiForm.Height);
18. if (hbitmap != IntPtr.Zero)
19. {
20. IntPtr ip = SelectObject(hdcMem, hbitmap);
21. if (ip != IntPtr.Zero)
22. {
23. bool a = PrintWindow(m_pFremework.MdiForm.Handle, hdcMem, 1);
24. DeleteObject(hbitmap);
25. Image tempImg = Image.FromHbitmap(hbitmap);
26. Bitmap b = new Bitmap(tempImg);
27. MyImage = b.Clone(rect, b.PixelFormat);
28. }
29. }
30. }
31. }
33. return MyImage;
34. }