给窗体中控件绘图的几种方法

方法一：WINDOWS API画法

//获取要绘制的控件句柄

Image img = GetWindow(this.tabPage12.Handle);

//在母容器上创建图形对象

Graphics gOut = mOut.pnlOut.CreateGraphics();

//在指定位置按指定大小绘出image

gOut.DrawImage((Image)img, form1.pnlImage.DisplayRectangle, this.tabPage12.DisplayRectangle, GraphicsUnit.Pixel);

//释放图形对象所有资源

gOut.Dispose();

img.Dispose();

GC.Collect();

form1.pnlImage.BringToFront();

#region 截图函数

[DllImport("gdi32.dll")]

public static extern IntPtr CreateDC(

string lpszDriver, //
driver name驱动名

string lpszDevice, //
device name设备名

string lpszOutput, //
not used; should be NULL

IntPtr lpInitData //
optional printer data

);

[DllImport("gdi32.dll")]

public static extern int BitBlt(

IntPtr hdcDest, //
handle to destination DC目标设备的句柄

int nXDest, //
x-coord of destination upper-left corner目标对象的左上角的X坐标

int nYDest, //
y-coord of destination upper-left corner目标对象的左上角的Y坐标

int nWidth, //
width of destination rectangle目标对象的矩形宽度

int nHeight, //
height of destination rectangle目标对象的矩形长度

IntPtr hdcSrc, //
handle to source DC源设备的句柄

int nXSrc, //
x-coordinate of source upper-left corner源对象的左上角的X坐标

int nYSrc, //
y-coordinate of source upper-left corner源对象的左上角的Y坐标

UInt32 dwRop //
raster operation code光栅的操作值

);

[DllImport("gdi32.dll")]

public static extern IntPtr CreateCompatibleDC(

IntPtr hdc //
handle to DC

);

[DllImport("gdi32.dll")]

public static extern IntPtr CreateCompatibleBitmap(

IntPtr hdc, //
handle to DC

int nWidth, //
width of bitmap, in pixels

int nHeight //
height of bitmap, in pixels

);

[DllImport("gdi32.dll")]

public static extern IntPtr SelectObject(

IntPtr hdc, //
handle to DC

IntPtr hgdiobj //
handle to object

);

[DllImport("gdi32.dll")]

public static extern int DeleteDC(

IntPtr hdc //
handle to DC

);

[DllImport("user32.dll")]

public static extern bool PrintWindow(

IntPtr hwnd, //
Window to copy,Handle to the window that will be copied.

IntPtr hdcBlt, //
HDC to print into,Handle to the device context.

UInt32 nFlags //
Optional flags,Specifies the drawing options. It can be one of the following values.

);

[DllImport("user32.dll")]

public static extern IntPtr GetWindowDC(

IntPtr hwnd

);

public Bitmap GetWindow(IntPtr hWnd)

{

IntPtr hscrdc = GetWindowDC(hWnd);

Control control = Control.FromHandle(hWnd);

IntPtr hbitmap = CreateCompatibleBitmap(hscrdc, control.Width, control.Height);

IntPtr hmemdc = CreateCompatibleDC(hscrdc);

SelectObject(hmemdc, hbitmap);

PrintWindow(hWnd, hmemdc, 0);

Bitmap bmp = Bitmap.FromHbitmap(hbitmap);

DeleteDC(hscrdc);//删除用过的对象

DeleteDC(hmemdc);//删除用过的对象

return bmp;

}

#endregion

方法二、给background赋值

Bitmap bmp = new Bitmap(this.tabPage12.Width, this.tabPage12.Height);

//将控件区域显呈到指定位图

this.tabPage12.DrawToBitmap(bmp, this.tabPage12.DisplayRectangle);

form1.pnlImage.BackgroundImage = (Image)bmp;

/* 分屏显示座席 */

form1.pnlImage.BackColor = Color.White;

form1.pnlImage.BringToFront();

方法三、将某个屏幕位置拷贝到image

Image img = new Bitmap(tabPage13.Width, tabPage13.Height);

Graphics g = Graphics.FromImage(img);

g.CopyFromScreen(Obj.PointToScreen(Point.Empty), Point.Empty, tabPage13.Size);

IntPtr dc1 = g.GetHdc();

g.ReleaseHdc(dc1);

form1.pnlImage.BackgroundImage = img;

form1.pnlImage.BringToFront();