trying to implement an xna game with a transparent window (showing the desktop or whatever behind it). Found a few people asking but no relevant answers.
I can get the form and set TransparencyKey
Form gameForm = (Form)Form.FromHandle(Window.Handle);
gameForm.TransparencyKey = System.Drawing.Color.FromArgb(255, 0, 0, 255);
then in the draw method i clear it to Red, and from my understanding Transparency key should remove anything red from being drawn, so the red background should go poof!
Does anyone know if I'm missing something or has more insight?
Related
Need a quick suggestion for styling a WinForm. I made it with rounded corners even when re-sized. Now trying to add a close button with a image (ControlBox=false), overlapping or clipped to top right corner. This is what I could end with.
But I wish to make it more like in this example image.
How could I achieve this in WinForm.
Here's the trick : your window doesn't just end with the white part. It extends a little bit further. The close button comes under the 'extra' part. The other sides where the window appears to not be there is actually transparent...or in the case of the image, semi-transparent.
The glow effect is provided by the window. Set the TransparencyKey property of the window to Color.Magenta (its a convention as Magenta is the color least likely to be used in a window). Then set the background image to a white background with a little bit of Magenta in the edges. The Magenta will appear transparent when set as the background image.
Fiddle around with TransparencyKey and you'll understand what I mean
Winforms itself cannot provide this for you without outside manipulation of the windows,
because it still uses win32 windows classes in the background.
If you want transparancy in windows: see articles like:
Cool, Semi-transparent and Shaped Dialogs with Standard Controls
And the method in Win32 to do it:
SetLayeredWindowAttributes
im developing a custom form and i want that the non-client area be transparent. im handling the non client area painting via message number "0x85" and this is what i have tried so far:
Paint using the color "Color.Transparent" -> the non-client area was painted black. If I had used an image of red or black or green, it works perfectly, but transparent = black
Created a transparent image of the size of the form and used the method "myGraphics.DrawImage("img.png")". the background remained black. If I had used an image of red or black or green, it works perfectly also...
Not paint anything (hoping that i just would stay transparent)... not worked
Getting parts of a window transparent requires hardware support, a video adapter feature called layering. Use the form's TransparencyKey property. Set it to an unusual color, like Color.Fuchsia. And draw with that color to get the video adapter to omit the pixels.
I think I must be missing something obvious, but I'm unable to find this after several hours of searching. Is there no way to use a PictureBox or other control to contain an image with partial transparent/alpha-blended pixels, and place that over another image and have the blending be based on the image under it?
For example, this produces the results I want:
Place a panel on a form.
Add an OnPaint handler.
In the OnPaint handler draw 1 PNG, then draw another PNG over it, using Graphics.DrawImage for both.
This does not:
Place a PictureBox on a form and set it to a PNG.
Place another PictureBox on the form and set it to a PNG.
Place the 2nd picture box over the first.
...even if the 2nd picture box is just empty and has a background color of Transparent, it still covers the picture below it.
I've read this stems from all winform controls being windows, so by nature they aren't transparent.
...but even the 15 year old platform I'm migrating from, Borland's VCL, had several windowless controls, so it's hard to imaging winforms doesn't at least have some easy solution?
My first example above is one answer, true, but that adds a lot of work when you can only use one big panel and draw all of your "controls" inside of it. Much nicer if you can have separate controls with separate mouse events/etc. Even if not an image control, and a control I have to draw myself, that would be fine, as long as I can just put one image in each control. In VCL they called this a "paint box", just a rectangle area you could place on a form and draw whatever you want on it. Has it's own mouse events, Bounds, etc. If you don't draw anything in it, it is like it's not even there (100% transparent) other than the fact it still gets mouse events, so can be used as a "hot spot" or "target" as well.
The PictureBox control supports transparency well, just set its BackColor property to Transparent. Which will make the pixels of its Parent visible as the background.
The rub is that the designer won't let you make the 2nd picture box a child of the 1st one. All you need is a wee bit of code in the constructor to re-parent it. And give it a new Location since that is relative from the parent. Like this:
public Form1() {
InitializeComponent();
pictureBox1.Controls.Add(pictureBox2);
pictureBox2.Location = new Point(0, 0);
pictureBox2.BackColor = Color.Transparent;
}
Don't hesitate to use OnPaint() btw.
Sorry, I just found this... once I decided to Google for "winforms transparent panel" instead of the searches I was doing before, the TransPictureBox example show seems to do exactly what I need:
Transparency Problem by Overlapped PictureBox's at C#
Looks like there are 2 parts to it:
Set WS_EX_TRANSPARENT for the window style
Override the "draw background" method (or optionally could probably make the control style Opaque).
I have to create a program that starts with a splash screen and a transparent image, but in windows form not working there always the white background, how can I do?
You need to set a transparency key. If you set it to white, it will make everything that's white on the form transparent (doesn't work well with the picturebox control though).
So for instance, you create a panel, and give it the background image you want to be displayed, then set the transparency key to whatever color should be made transparent ;p
I need to capture the entire screen with a transparent WPF window as the topmost window.
I tried 2 approaches:
using System.Windows.Drawing.Graphics.CopyFromScreen
using WINAPI GetDesktopWindow
Both methods yield the same result. I get the entire screen EXCEPT my topmost transparent WPF window.
The WPF window w is created with:
w.AllowsTransparency = true;
w.WindowStyle = System.Windows.WindowStyle.None;
w.Background = new SolidColorBrush( Color.FromArgb( 1, 0, 0, 0 ) );
w.Topmost = true;
plus some content of course. The window covers the entire screen surface.
Apparently, the WPF window draws on a surface that is not included in GetDesktopWindow.
Can anybody pls shed some light on this and share some ideas how to truly get the entire screen surface?
Just found the solution:
As far as I can tell there is no solution for the Graphics.CopyFromScreen approach because you'd need to OR CopyPixelOperation.CaptureBlt with CopyPixelOperation.SourceCopy but you can't. The usual M$ inconsistency madness...
However, the WINAPI approach works since you can combine SRCCOPY and CAPTUREBLT when using BitBlt. Without CAPTUREBLT transparent and layered windows will not be included.