如何截取pictureBox1句柄窗口的截图？

Question

我正在使用这个类，但它会截取桌面句柄的截图。 我需要截取pictureBox1句柄的截图。

#region Class Imports 
using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using System.ComponentModel;
#endregion

namespace Test
{
    /// <summary>
    /// Class for taking a screen shot in code
    /// </summary>
    public class ScreenShot
    {
    /// <summary>
    /// Global variable declarations
    /// </summary>
    #region Global Variables
    private Bitmap _screenShot;
    protected static IntPtr newBMP;
    #endregion

    #region Constants
    public const int SRCCOPY = 13369376;
    public const int SCREEN_X = 0;
    public const int SCREEN_Y = 1;
    #endregion
    /// <summary>
    /// Hold the definition for the
    /// class properties
    /// </summary>
    #region Class Properties
    [Description("Gets the screenshot image")]
    public Bitmap ScreenImage
    {
        get { return _screenShot; }
    }
    #endregion

    #region Constructor
    /// <summary>
    /// Constructors for our class
    /// </summary>
    [Description("Empty constructor, instantiating _screenShot to nothing")]
    public ScreenShot()
    {
        _screenShot = null;
    }              
    #endregion

    #region Methods
    /// <summary>
    /// Method for creating an image of the current desktop
    /// </summary>
    /// <returns>A Bitmap image</returns>
    [Description("Creates an image of the current desktop")]
    public Bitmap GetScreen()
    {
        int xLoc;
        int yLoc;
        IntPtr dsk;
        IntPtr mem;
        Bitmap currentView;

        //get the handle of the desktop DC
        dsk = Win32API.GetDC(Win32API.GetDesktopWindow());

        //create memory DC
        mem = Win32API.CreateCompatibleDC(dsk);

        //get the X coordinates of the screen
        xLoc = Win32API.GetSystemMetrics(SCREEN_X);

        //get the Y coordinates of screen.
        yLoc = Win32API.GetSystemMetrics(SCREEN_Y);

        //create a compatible image the size of the desktop
        newBMP = Win32API.CreateCompatibleBitmap(dsk, xLoc, yLoc);

        //check against IntPtr (cant check IntPtr values against a null value)
        if (newBMP != IntPtr.Zero)
        {
            //select the image in memory
            IntPtr oldBmp = (IntPtr)Win32API.SelectObject(mem, newBMP);
            //copy the new bitmap into memory
            Win32API.BitBlt(mem, 0, 0, xLoc, yLoc, dsk, 0, 0, SRCCOPY);
            //select the old bitmap into memory
            Win32API.SelectObject(mem, oldBmp);
            //delete the memoryDC since we're through with it
            Win32API.DeleteDC(mem);
            //release dskTopDC to free up the resources
            Win32API.ReleaseDC(Win32API.GetDesktopWindow(), dsk);
            //create out BitMap
            currentView = Image.FromHbitmap(newBMP);
            //return the image
            return currentView;
        }
        else  //null value returned
        {
            return null;
        }    
    }
    #endregion

    #region Helpers
    [Description("Takes the information from GetScreen and creates a Bitmap image")]
    public void GetScreenShot(string folder, string name)
    {
        //check to see if the folder provided exists
       /* if (!Directory.Exists(Application.StartupPath + "\\" + folder))
        {
            //if it doesnt exist then we need to create it
            Directory.CreateDirectory(Application.StartupPath + "\\" + folder);
        }*/
        //set the ScreenImage Property to the
        //BitMap created in GetScreen()
        _screenShot = new Bitmap(GetScreen());
        //create a name based on the name passed in
        string ingName = folder + name + Elgato_Video_Capture.counter.ToString("D6") + ".bmp";
        //save the image
        _screenShot.Save(ingName);
        _screenShot.Dispose();
    }
    #endregion
    }

}

然后我就这样使用它：

    ScreenShot shot = new ScreenShot();
    public static int counter = 0;

    private void timer1_Tick(object sender, EventArgs e)
    {
        counter++;

        shot.GetScreenShot(@"e:\screenshots\", "screenshot");
        if (counter == 1200)
        {
            timer1.Stop();
        }
    }

我需要截取pictureBox1.Handle窗口的截图而不是pictureBox1.Image。 问题是ScreenShot类截取了桌面Handle的截图，我只想截取pictureBox1.Handle的截图