Is it possible to get a screenshot of a window that is not on the top, i.e. if it is partially hidden by another window, without bringing it to the top?
Unfortunately, it's not trivial to take a screen-shot in C# at all, you can create a graphics object based on the current window or viewport and capture that, but its not what you're asking for.
This
Screenshot of Hidden Window
might help, but you'd have to do this with Interop code anyway.
I dare say that it's not a common thing that is supported as really, one program has no business knowing what's being displayed in another program; it's potentially a nasty exploit.
You dont need to take screenshot, if it is your application you can use Control.DrawToBitmap(Bitmap bitmap, Rectangle targetBounds); of the form object.
If it is other application window, you can try un-managed way to get the UI of window. I dont remember all the methods but I have tried and it was working. Probably GetWindow and SendMesage with WM_PRINT / WM_PRINTCLIENT
Related
I'm trying to make, essentially, a screen capture program, that captures the pixel values under the current window. (I'm working in C#, in Visual Studio 2015.) However, for various reasons, the window itself needs to be opaque (for filters and such). How can I best achieve this?
It is possible to find the window below yours and get a screenshot of it even if it is hidden with the method: PrintWindow (see PInvoke.net as well)
See Copying content from a hidden or clipped window in XP?
It is very simple to do in Winforms. Just set the form's Opacity value to 99%. Now Graphics.CopyFromScreen() will not see your window anymore.
Except when the window underneath yours is also a layered window, then it also won't be visible to CopyFromScreen() for the same reason. Then you have to set Opacity to 0, copy and set it back to 0.99. Very quick, probably good enough for what you want to do.
I used this code from the code project in order to display a .png image (with transparency). At line 87 I tried to add a label in which I succeeded but somehow It won't appear on the form. I tried Refresh, Invalidate but none of them worked. Maybe someone can point me into the right direction.
I think, since you're using UpdateLayeredWindow the "normal" painting mechanism is disabled, i.e. no WM_PAINT messages are sent to the window, and the WinForms library has no chance to render the Label Controls.
I found this article about using layered windows on MSDN stating:
Note that when using UpdateLayeredWindow the application doesn't need to respond to WM_PAINT or other painting messages, because it has already provided the visual representation for the window and the system will take care of storing that image, composing it, and rendering it on the screen. UpdateLayeredWindow is quite powerful, but it often requires modifying the way an existing Win32 application draws.
So I'm afraid that WinForms isn't able to work together with your approach. Even if it would, you would likely get unpleasant results since "real" transparency is not easily done with winforms (i.e. the labels wouldn't show up transparently but would be drawn the parent forms background color)
I have an design idea about the appearence of a small program , which is basically a windows form with a combo and one button.What i would like to do is the following.When i click on the .exe of the program to start it , i would like to have an non-standart start up of the window.To be more specific i will give you an example - i click on the .exe , upon which some dots appear in a random matter all over the screen , after those points appear they start moving in a spiral way so finally they merge into the standart square windows form shape.So my question is - is there a free API or anything similar with the help of which its easily doable or there would be a lot of work needed from myself to create those API's ?
Thanks in advance
This will be extremely difficult to do.
It will also be very annoying for the end-users.
In short I see two options:
Render your form to a bitmap and render peices of the bitmap to a full-screen layered window. You'll have to call UpdateLayeredWindow repeatedly to get the animation working but that should be a good lead. I could see getting 10-20 fps with this method.
Take a screenshot of the desktop, create a full screen borderless topmost window, render the screenshot, then render your animation on top. This will prevent any other windows from recieving input while the animation is playing.
Either way your users will hate you.
As SLaks has already said, that will be pretty annoying for the end-users.
If you ask whether it is doable, I would say yes, everything is doable in programming, it all depends on the effort you're ready to put into.
As a very simple algorithm, here are some steps I would go through for your achievement:
Create a System.Windows.Forms.Form;
Set Form.ShowInTaskBar= false;
Set the Form.TransparencyKey property;
Set the Form.ControlBox= false;
Set Form.TopMost= true;
Drop a PictureBox control on your Form;
On the Form.Load event, take a screenshot of the current desktop and set it as the image of your PictureBox.
Then, build an animated GIF, and superpose it to your form.
You will most likely appreciate, I guess, the following link which discusses about C# Winforms Animation.
Disclaimer: This is an arbitrary algorithm off the top of my head. Besides, I illustrated the steps I would go through in order to achieve such objective, though I have never ever performed WindowsForms animation.
Althouth this might be cool to program, users are conservatives and "always anxious" about program startups, so, as already mentioned, this might become pretty annoying for the end-users.
I hope this helps you through anyway!
I need to capture a screenshot of the scrolling window's client area, using .NET. My first priority is capturing web page screenshots. But this can be not the only one use case. For example it can be also a text area in the Notepad.
Some applications (FastStone Capture, PicPick) can emulate user behavior to reach hidden part of a scrollable area and capture it. I'm looking for something like this or recommendations for alternative way to get the same result.
You can get windows to redirect a WM_PAINT to an offscreen buffer with WM_PRINT and WM_PRINTCLIENT. This is better than screenscraping because it makes sure that obscured parts of a window(behind other windows) is painted anyway. If your target window scrolls by scrolling a child window position, WM_PRINT should apply. Just maybe it also helps your scenario.
I've continued my search and founded IECapt, — an open source tool which can take a web page screenshot using IE inside of it. It has С++ and .NET versions. Also there are Qt/WebKit-based analog from the same author: http://cutycapt.sourceforge.net.
This tools is not a direct answer for my question, but both of them solve the original problem by 90%.
Have you looked at Snagit? http://www.techsmith.com/download/accessories/default.asp
Also, here's a c# utility that seems to do what you're asking for: http://www.codeproject.com/KB/graphics/IECapture.aspx
I implemented something in Windows Forms similar to DragMove but with boundaries set to 10 units of the margins of the primary screen.
When switching over to WPF I found this thread to be useful in achieving the same result.
However, since this is a post-move event, what happens is that if my window is dragged beyond the boundaries I set, it "jumps" back. I would like to avoid this effect as it looks terrible.
Is there a simple way to avoid the window to be moved outside a given area without using the LocationChanged event? I basically want to restrict the movement of the window before it happens.
These this are very hard to achieve with WPF because it does not expose the base Win32 functions and events like WinForms did. I had a project where I needed to to resize a window and I had to use PInvoke SetWindowPos to do this in a normal manner.
AddHook may help you, but this will still be quite difficult. See http://www.wpfmentor.com/2009/01/how-to-get-hwnd-and-hook-into-wndproc.html and http://msdn.microsoft.com/en-us/library/system.windows.interop.hwndsource.addhook.aspx for more information.