using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
class HTMLImageCap
{
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
//use win32 api
private class Gdi32
{
[DllImport("gdi32.dll")]
public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hObjectSource, int nXSrc, int nYSrc, int dwRop);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth, int nHeight);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
}
private static class User32
{
[DllImport("user32.dll")]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("user32.dll")]
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
}
//define constants
private const int SRCCOPY = 13369376;
private const int LOOPTIMES = 40;
private const int SLEEPTIME = 100;
private static int getXoffset(HtmlElement he)
{
//get element pos
int xPos = he.OffsetRectangle.Left;
//get the parents pos
HtmlElement tempEl = he.OffsetParent;
while (tempEl != null)
{
xPos += tempEl.OffsetRectangle.Left;
tempEl = tempEl.OffsetParent;
}
return xPos;
}
private static int getYoffset(HtmlElement he)
{
//get element pos
int yPos = he.OffsetRectangle.Top;
//get the parents pos
HtmlElement tempEl = he.OffsetParent;
while (tempEl != null)
{
yPos += tempEl.OffsetRectangle.Top;
tempEl = tempEl.OffsetParent;
}
return yPos;
}
private static Image captureWindow(IntPtr handle, int x, int y, int width, int height)
{
IntPtr hdcSrc = User32.GetWindowDC(handle);
RECT windowRect = new RECT();
User32.GetWindowRect(handle, ref windowRect);
IntPtr hdcDest = Gdi32.CreateCompatibleDC(hdcSrc);
IntPtr hBitmap = Gdi32.CreateCompatibleBitmap(hdcSrc, width, height);
IntPtr hOld = Gdi32.SelectObject(hdcDest, hBitmap);
Gdi32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, x, y, SRCCOPY);
Gdi32.SelectObject(hdcDest, hOld);
Gdi32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
Image img = Image.FromHbitmap(hBitmap);
Gdi32.DeleteObject(hBitmap);
return img;
}
public static Image getImage(WebBrowser wb, HtmlElement he)
{
//get original scroll position
int docY = wb.Document.GetElementsByTagName("HTML")[0].ScrollTop;
int docX = wb.Document.GetElementsByTagName("HTML")[0].ScrollLeft;
//scroll to view element
wb.Document.Window.ScrollTo(getXoffset(he), getYoffset(he));
int heY = getYoffset(he) - wb.Document.GetElementsByTagName("HTML")[0].ScrollTop;
int heX = getXoffset(he) - wb.Document.GetElementsByTagName("HTML")[0].ScrollLeft;
int heWidth = he.OffsetRectangle.Width;
int heHeight = he.OffsetRectangle.Height;
Image img = captureWindow(wb.Handle, heX, heY, heWidth, heHeight);
//scroll back tooriginal position
wb.Document.Window.ScrollTo(docX, docY);
return img;
}
}
Put this class in your project and use like this
string Url = "https://accounts.google.com/SignUp";
webBrowser1.Navigate(Url);
//Wait for few secs
HtmlElement sliderWrap = webBrowser1.Document.GetElementById("recaptcha_image");
Image i = HTMLImageCap.getImage(webBrowser1, sliderWrap);
i.Save(Application.StartupPath + "\\text.jpg");