How to determine if Form is obscured.

• Jul 29, 2009

• #2

HughLerwill

Programmer

Nov 22, 2004

1,818

GB

Could a call to GetForeGroundWindow be of help?

http://msdn.microsoft.com/en-us/library/ms633505(VS.85).aspx

 

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• Jul 29, 2009

• #3

HarleyQuinn

Programmer

Jan 15, 2003

4,769

GB

Is the Windows Form a form you've created in C#?

If so how are you creating the bitmap of the form (and I assume, it's controls)?

HarleyQuinn
---------------------------------
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• Jul 29, 2009

• #4

strongm

MIS

May 24, 2001

20,264

GB

>needs to create a bitmap image of a Windows Form

How are you doing that?

 

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• Jul 29, 2009

• Thread starter
• #5

ROGERDODGE

IS-IT--Management

Aug 13, 2003

40

GB

The form which I need to Capture is from another application, I have no control over it programmatically.

Essentially, I am trying to "scrape" information from the form to then do some look-ups in a database from predetermined areas (fields) on the form.

I have set up some code within a "dummy" form, so when I click a button, I call this code which then gets the handle of itself and then captures the screen from its position, this works fine.

Code:

[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);

[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
    public int Left;
    public int Top;
    public int Right;
    public int Bottom;
}

private void cmdOptions_Click(object sender, EventArgs e)
{
RECT rct;
HandleRef lcHnd = new HandleRef(this, this.Handle);
if (!GetWindowRect((IntPtr)lcHnd, out rct))
{
    MessageBox.Show("ERROR");
}
else
{
    int windowWidth = System.Math.Abs(rct.Right - rct.Left);
    int windowHeight = System.Math.Abs(rct.Bottom - rct.Top);
    System.Drawing.Bitmap currBMP = new Bitmap(windowWidth, windowHeight);
    currBMP = CaptureClip(rct.Left,rct.Top, windowWidth, windowHeight);
                currBMP.Save("C:\\OCRSDK\\CaptBMP.bmp");
}
}

The CaptureClip function just "grabs" the defined area from the screen.

I have been exploring the possibilities of using "WindowFromPoint" and "PtInRect" API functions to try to figure something out.

RogerDodge

 

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• Jul 29, 2009

• #6

Hypetia

Programmer

Feb 26, 2003

1,279

US

You might want to use the PrintWindow function which captures the window easily and works even if the window is obscured by other windows.

 

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• Jul 29, 2009

• #7

strongm

MIS

May 24, 2001

20,264

GB

>The CaptureClip function just "grabs" the defined area from the screen

It is how the grabbing is being done that I was asking about. Unfortunately what you have posted show this. And I am not familiar with the CaptureClip function. Is this something that you wrote? And if so, can we see it please?

 

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• Jul 29, 2009

• Thread starter
• #8

ROGERDODGE

IS-IT--Management

Aug 13, 2003

40

GB

I'll try the PrintWindow tomorrow when I'm back @ work - thanks.

strongm - here's the code (for clarity's sake)
(thanks to Danny Battison)

Code:

public static System.Drawing.Bitmap CaptureClip(int x, int y, int width, int height)
{
	System.Drawing.Bitmap BMP = new Bitmap(width, height, 
	                                       System.Drawing.Imaging.PixelFormat.Format32bppArgb);
	System.Drawing.Graphics GFX = System.Drawing.Graphics.FromImage(BMP);
	GFX.CopyFromScreen (x, y, 0, 0, new Size(width, height),
	                    System.Drawing.CopyPixelOperation.SourceCopy);
	
	return BMP;			
}

I'm sure I can tidy this code up a bit, but for the moment I just need the principles to work.

My main issue at the moment is to capture the hidden window (normally it wont be hidden but I cant be certain so I need to either trap it or not care - hopefully the PrintWindow will solve it.

 

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• Aug 8, 2009

• #9

Mike Gagnon

Programmer

Apr 6, 2002

8,067

CA

How does that relate to Foxpro?

Mike Gagnon

If you want to get the best response to a question, please check out FAQ184-2483 first.
ReFox XI (www.mcrgsoftware.com)

 

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• Aug 8, 2009

• Thread starter
• #10

ROGERDODGE

IS-IT--Management

Aug 13, 2003

40

GB

It doesn't specifically? Should it?

 

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• Aug 8, 2009

• Thread starter
• #11

ROGERDODGE

IS-IT--Management

Aug 13, 2003

40

GB

Mike - I think I may have misunderstood your question. Being more awake! and looking at the links under your post, it may be that we are looking at the same underlying issues.
The application(s) which I am trying to "screen scrape" have all (as far as I can make out) been developed with Foxpro9. As a consequence, it seems that I am unable to enumerate any objects on the child forms. In some applications, the relevant information which I am trying to obtain, ie client reference number, is present on the main window title text - I can then just use this information to do a lookup of the appropriate database record.
I will be interested to hear from you.

 

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• Aug 13, 2009

• #12

luckieluc

Programmer

Jul 29, 2009

50

BE

I should try to solve this problem on two ways:

Because your CaptureClip-function use the graphic handle of the console-screen (I actually more guess it then I known) I should make/force the window as Top-Level-Window during the capture period.

Or:

I would try to give a repaint-command of the window that you like to capture, but to the canvas of an bitmap instead of those of the Form.

 

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