When I fix a Background to my winform, It is getting blink on form load. I have a table layout panel on my form and I kept all my controls on the table layout panel.
I set the backcolor of tablelayout panel to Transparent and Set the Image to the background. Why am I getting blink on my form load?
WinForms doesn't handle transparency very well (As I'm sure you may have noticed, not all WinForms controls even support it). The blink is caused because as your TableLayoutPanel is loaded, as well as all its items, the Form has to find the correct 'image' (Because the control doesn't support transparency in the same way as WPF or a game does, it instead uses an image of the controls behind it) to display. It must go through this process as each of your controls are loaded, hence the blinking. You can try enabling DoubleBuffering on your Form, however, if I recall correctly, this can cause issues with transparency.
If you find that you are using a lot of transparency and/or want to customise your Form a lot more, I suggest you take a look at WPF. It offers far greater control over your Form (Window in WPF) as well as supporting transparency on every single control.
Related
I have a problem with the opacity of some controls.
So I set the form opacity to 0.3, when the form is loaded, and the problem is that it makes the other controls as tranparent as the form. Here is the code.
private void Form1_Load(object sender, EventArgs e)
{
this.Opacity = 0.3;
}
By doing this, all my controls are as transparent as the form. Is there any way to have different opacity for the controls inside the form ? I don't want the other to be transparent at all.
My first recommandation would be to avoid that. Having a semi-transparent background with opaque controls will look somewhat weird. Instead, consider changing the opacity when the form is active say from 0.3 to 0.7 so that it is easier to read.
Also another problem if some controls are opaque and the background is almost transparent, then your UI might not work well on some background. For example, if the background is really dark, then dark text (control) will be hard to see. If the background is white, then white controls like edit box would be the same color as the background.
You can get a few idea from other people comments. Even though some comment are for WPF, you might be able to take some idea for WinForms. And if you don't get the expected result, you might also consider using WPF for that part of the UI.
Having said that, a possible workaround to get what you want is to create two top-level windows at the same position (and move/resize them as appropriate). That way, you can have one window with a transparency key and the desired background for opaque area that will be used to have opaque and semi-transparent area. The other window will use the opacity so that it would be semi-transparent. This is the window that will contain your UI controls (and the one that would be on the top).
I have used that technic in the past to have a semi-transparent client area with a fully opaque frame in one application where I want to be able to see through client area (adjustable opacity) so that I could "draw" in my window using the image in another application as a reference.
Another comment is that you might need actual control with windows handle and direct Win32 API access for some customization that are not available in WinForms and/or WPF. In my application, I was handling activation in a way that if I click on the bottom level windows, the top-level window still appears as the active one (caption bar color). If one has no standard caption bar (either the frame is custom or no frame at all), then you would not have that problem.
As suggested by some links in the comment section, it might also be possible to get what you want using a single top-level windows. I have not tried that. In fact, when I try the above solution, I think that my application was still supported on Windows XP and as such you are more limited in options and the behavior is somewhat different essentially because XP more or less write directly to screen while Vista and later use bitmaps (buffers) for each windows.
I have also used combined transparency key and opacity for splash screen (on a single window) and it works on most system but sometime I got black background instead of desired background on some system (probably some XP machine with specific configuration).
I'm making C# application design with images, but when I launch it, I see loading images (~1sec), so how to make simple loader, when images (background, logo, etc..) fully loads, to show my app? I know it's possible but I don't know how to. Thanks so much!
This sounds like standard behaviour. The controls get painted one by one in z-order and if one is slow the rest may appear to flicker.
You could try double buffering the whole form as shown here:
How to fix the flickering in User controls
Alternatively you could suspend the layout while everything is drawn and resume it afterwards:
How do I suspend painting for a control and its children?
I have a transparent Windows Forms Form with a few custom usercontrols on it.
These controls have some transparency themselves.
The problem is that these controls overlap each other a little. The overlapping part is transparent so that shouldn't be a problem. Unfortunately it isn't working like it should instead of the transparency to show the control below it cuts out that part of the control.
Does anyone know what could be the problem here and how to solve it?
In a WPF application I have a user control that hosts a win forms RichTextBox control using the WindowsFormsHost. The user control is used in a panel that is made visible at a certain time. The problem is that the forms control is displayed a few moments before the containing panel. I tried delaying the display of the RTB until the panel is shown, but then the UI freezes for 2-4 seconds when the forms control is loaded. Please help if you know a solution to make the control load faster. Thanks!
You should use a profiler to see where most of the time is consumed, have a look here: What Are Some Good .NET Profilers?
I managed to find a solution for this :) Actually, the WindowsFormsHost had a Transparent background set, and just removing the transparency solved the performance problem.
I have a form that contains a lot of runtime generated controls (image, button, panel,...), about 100 controls (I'm making a card matching game so there is a lot of controls in the form).
I place the generating code into the constructor and each time the app starts, it took about 3-5s to load all the controls completely.
If I bring another window on top and then back to my app, the controls will be redrawn again.
How can I prevent the controls from being redrawn? If you don't mind, please give me a simple example in C#.
Any help is appreciated!
I found this article that explains how to do this in .NET by calling the WIN API SET_MESSAGE function to set the WM_SETREDRAW flag for the control you do not want updated. Although you can stop certain controls from updating, are you sure you can't approach this issue by reducing the number of controls on the page? 100 Controls seems like a lot and may be an indication that you need to have multiple views.
Enjoy!
My suggestion is to use the form as a drawing surface and draw your card bitmaps directly onto the form. Its not hard to do.
You can add a handler to the form Paint event which will give you parameters with a Graphics object. Use graphics.DrawImageUnscaled to draw each card at the location you want.
This will make the app much much faster.
Preventing a control from redrawing is fairly pointless. You'll get a hole where a control was supposed to appear, your user won't have any use for that hole.
It redraws slowly simply because you have too many controls. You can only get it to redraw faster by using less controls. Or by using controls that can display multiple items in one window, like ListBox, ListView, TreeView, DataGridView.
Note that your specific issue is fixed in Vista and Windows 7. The Aero theme uses off-screen buffering for windows. Which means that windows don't need to repaint themselves anymore when they are obscured by another window. You will however still get slow redraws when the user minimizes the window and restores it.
You might want to consider using a single data table control. A ListView (or something like ObjectListView) may be a good option.
If your data isn't really a list/table, you should split the controls into separate tab pages, which would improve both performance and usability.