I want to show a transparent panel on top of another panel, both the panels have child controls like labels, text boxes etc. Transparency works fine if the transparent panel is child control of the other panel but if not then the label and text box of the normal panel appears on top of the transparent panel. Transparency for rest of the area works fine.
Any ideas ???
I have tried bring the transparent panel to the front but did not help. Perhaps I need to specify the order in which the controls should be drawn ?? If yes how do I do that ?
Interestingly if I move the application below the task bar and bring it up. It achives the right result. ( Reprinting resolves the issue !! but why??). However when I minimize it and restore it does not fix it!
Thanks,
Transparency in Windows.Forms is implemented by relational hierarchy rather than visual hierarchy. When a transparent control is painted, .NET basically calls up the Parent tree asking each parent control to paint itself, then paints the actual control content itself.
Two siblings in the same control will paint over each other.
So to answer the question, the topmost panel/control needs to be a child of the control you want to paint on top of.
If you want a transparent control that won't obscure its siblings, according to Bob Powell you can do it by overriding the CreateParams method to add true transparency. Read the link for a full description.
If all your panels/labels/controls are part of a single UserControl then you are probably right that you just need to set the Z-order (the front-to-back order). You can do this using the Document Outline inside of Visual Studio's Designer under View > Other Windows > Document Outline.
If you're doing it programatically then you can play around with calling Control.BringToFront() or Control.SendToBack() to change their z-order. One possible way to do this is like (assuming ctl1 is intended to be at the back and ctl4 is intended to be front-mode.
SuspendLayout()
ctl1.BringToFront()
ctl2.BringToFront() ' Bring ctl2 in front of ctl1
ctl3.BringToFront() ' 3 in front of 2 (and in turn 1)
ctl4.BringToFront() ' 4 in front of the rest
ResumeLayout()
The Suspend/Resume Layout calls prevent the UI from updating while you rearrange things.
Related
So I am working on a program that has several screens which causes it to have overlapping controls (Buttons and lists).
I put the controls in panels which works great and then do show/hide for the panels.
This also works well.
I am having a problem now that I am up to several panels where when I move one panel up it gets absorbed by another and I need them to stay separate.
Example: When I move panel2 into place over panel1, panel2 becomes part of panel1. Then when I do panel1.Hide() and panel2.Show(), panel2 is still hidden because it is part of panel1. is there a way for me to ungroup these or move panel2 into place without it automatically becoming part of panel1? (I know I can show hide the controls inside of the panels, but this will add a lot of complexity because I have a ton of controls)
Perhaps there is a better solution than using panels?
You can use the View + Other Windows + Document Outline tool window to get these panels separated again. Drag the inner panel back to the parent. You'll then also have to edit the Location property to get it back in the right position.
This is annoying of course and good odds that you'll have to do this repeatedly. There's a better way to go about it, a TabControl has good design-time support and also has the same "overlapping panel" metaphor. You just need to hide the tabs at runtime. That's pretty easy to do, check the StackPanel control in this answer.
I have a SplitContainer on my form that has its Dock property set to Fill. It contains several child controls, many of which have event handlers attached to them. Later I decide to put a StatusStrip at the bottom of my form. Guess what, I can't set the StatusStrip to dock to the bottom of my form. The SplitContainer will continue to Fill the entire form. Even though the StatusStrip apparently gets docked to the bottom, it actually hides the bottom part of the SplitContainer behind it.
The only around it is to CUT the SplitContainer and then PASTE it back. Cutting the SplitContainer makes the StatusStrip the only control on my form and thus lets it capture the bottom docking. Afterwards, pasting the SplitContainer allows it to fill the remaining area. In short, docking uses First Come, First Serve method.
Now since my controls have lots of event handlers attached to them, cutting and pasting becomes a nightmare for me. Having my project in C# means I have to attach all those event handlers manually.
Is there a better work around?
This is a z-order issue between the splitter and the statusstrip. When you have a control you want to dock fill and one or more controls you want to dock top, left, right, or bottom, you have to have the fill control be the first in the z-order.
The better way is to open the Document Outline tool, select the SplitContainer and use the up or down buttons to change its z-order.
I should add that in Winforms the z-order is specified by the order in which you add controls to the Controls collection. That order determines the order the associated system controls are created, hence their z-order. Using the Document Outline tool to alter z-order simply causes the generated code to be re-ordered.
I need to create a custom control that has an expandable part as a panel and a textbox part. The expandable part is a panel, that will either be visible or invisible. But when the panel is visible/expanded directly under the textbox, I do not want the adjacent controls to shift down below the panel, but the panel should just overlay the controls that are there just under the custom control. How would I implement this in Winforms C# project?
I am open to using user control for this scenario.
Thanks
Sunil
I think your implementation of expanding and collapsing is not the best, because you are just overlaying the controls instead of hiding them.
One of the disadvantages is that the overlaid controls might by focussed by pressing tab and they might have a value which I think it is out of target.
I would suggest another implementation by creating two panels (one for the header and another one for the content) and when the collapse button is pressed then the content's panel will be hidden by sitting its Visible property to false and its Hight to 0.
I'm writing a form in C# and have several panels. I need to draw a line between two of the panels. I've found online several ways to go about this, the most promising appears to be to create a third panel, make it transparent, place it on top of my original panels and draw the line here.
I'm not able to get the panel to be transparent, even if I set its BackColor and ForeColor properties to transparent (in code or in design view of VS).
Any ideas on how to make the panel itself transparent (or not Visible) but have the line I draw on it still visible on top of everything else?
Thanks in advance.
No, it's transparent. See this by giving the form's BackgroundImage a value. You'll see it through the transparent panel. Of course, that's not the kind of transparency you want, you want stacking effects to work. There is no direct support for that.
If you want layers to work then don't use controls. Use the Paint event to draw. Now there's no problem, if you want transparency then just don't paint. Draw a line across an image simply by drawing the image first. This is also the rendering model of WPF.
You can actually do this pretty easily as your own UserControl. Here's a code example:
Drawing on top of controls inside a panel (C# WinForms)
This is similar to what you were originally attempting to do, only instead of drawing a line on top of a transparent panel, this code creates an irregularly-shaped user control (which happens to be in the irregular shape of a line).
I've a strange problem regarding auto sizing of a panel in a user control. This panel is anchored to all 4 sides of the user control.
But the anchoring not always works as it should:
If the user control is resized by resizing the form, the right and bottom anchors don't work. But if the control is resized by using a splitter which is in the form, it works correctly.
All other controls which are also affected by resizing work correctly, just this panel won't do.
I can't see the difference between resizing through a splitter and through a form.
Setting the size manually in the OnResize of the UserControl only works if the resizing is done by moving the splitter. If the resizing occurs by resizing the form, the heigth and the width of the panel won't change to the new values.
Edit: To make it more clear: The user control is added to a TabPage and set to Dock=DockType.Fill.
Edit2: To make it more complicated: This is the hierarchy the control is used:
The Form contains a splitter with 2 controls (A and B). (B) contains a user control (C) with a splitContainer. The split container->panel1 in (C) contains a tabcontrol (D). This tabcontrol (D) contains a user control (E) (in a tabpage) . This user control (E) has a splitcontainer (F) in which another usercontrol with a tabControl (G) is placed. This tabcontrol (G) has tabpages, and in this pages is the described user control (H) placed.
If I place the control (H) directly to the panel in the splitcontainer (C) everything works fine. Since all controls which are added to a splitcontainer or a tabpage are set to docktype=fill, I cannot see why the last control has this problems.
Is there any limitation in the Windows Forms framework which limits the amount of child controls?
Edit: I have uploaded a TestApplication with which you can reproduce this issue.
http://rapidshare.de/files/49092516/TestApplication.zip.html
It occurs only under Vista. Win XP and 7 work properly...
If you resize the form, the textBox with the "..." button won't resize, but if you resize via the vertical splitContainer, it works.
There is a bug with deep nesting where the kernel runs out of stack space causing resizing, docking and anchoring to fail silently.
See https://web.archive.org/web/20140818095718/http://support.microsoft.com/kb/953934
You have talked about both "anchor" and "dock", which can serve similar purposes but act differently. Your problem may be that you are trying to do both, and this is interfering with the behavior you want. If not, perhaps try switching from the one to the other.
It sounds like you've double checked the ansectery of the control, but did you examine it with: View->Other Windows->Document Outline (a very handy tool I only recently discovered)?
Finally, while it doesn't directly solve your problem, it sounds like you have a very complicated UI, and your users may benefit if you were to spend some time to consider if you could simplify the UI. Of course, I don't know your users or the purpose of the app, and what you have may be the best, but it sounds like it might be time to ask this question.
Good luck.
The problem is not the depth of nesting; controls can be nested arbitrarily deep. Anchoring and Docking generally do not play nicely with each other. I usually favor docking over anchoring, but, whichever solution you choose, you should probably avoid mixing them.