So I have a fairly simple Winforms app. It has a panel with a bmp image that is being updated every second, via
Graphics.DrawImage
I want to be able to draw a rectangle over the updating images. There seems to be no way to do this in Winforms, however.
First, I tried drawing on the first panel, but there seems to be no way to set the z-index of Graphics elements, so every time the image gets updated, the rectangle is deleted.
Second, I tried making a second panel and drawing in it. Yet, it seems like there is no way to make a truly transparent panel in Winforms. I looked around for some workarounds, but it seems like all they do is essentially make the second panel part of the first, so the previous issue with the rectangle getting deleted arises again.
Is there anyway to do what I am trying to do? Without switching to WPF?
Related
I'm making a simple graphic editor in Windows Forms (C#), and I'm using a PictureBox for my canvas. I want to implement the "undo" functionality. I'm drawing using System.Drawing.Graphics. Here is my situation:
If I use picturebox.CreateGraphics(), then I will see the drawing, but it won't actually be made on the image (if afterwards I called pictureBox.Image.Save(...), the saved image would be blank).
If I use Graphics.FromImage(picturebox.Image), then the drawing will be actually made on the image, but I won't see anything.
How can I have both?
And how do I implement the undo functionality after that? I tried using Save() and Restore() on graphics, but it didn't work, maybe I misunderstood what these methods mean.
You should avoid using CreateGraphics since that is a temporary drawing that can get erased by minimizing the form or having another form overlap the graphic area, etc.
To update the PictureBox, just invalidate it after you have an update to the drawing:
pictureBox1.Invalidate();
The Undo-Redo is a different beast. That requires you to keep a list of things to draw and in order to undo something, you remove the item from the list and redraw the whole thing again from the active list.
i tried to search for this on google, but didnt seem to find anything related that could help me.
My problem is this, i have a panel in which i draw a cube, and i added a group box with 3 radio buttons and 4 normal buttons(these do the rotation of the cube)
For testing i have another button added on the panel but not in the group box.
The problem is this, when i push on any button it doesn't update the cube's rotation, only when i move the mouse on the test button(over it)
If i try to move the buttons outside the group box then all works well, but they don't work if they stay inside the group box.
Does anyone know how i can fix this?
May I suggest that instead of redrawing the panel you create a Bitmap for drawing your (rotated) cube and use a PictureBox to display it? The PictureBox could be inside the Panel together with the GroupBox.
The flickering comes because the panel redraws his background first and then raises the Paint event. To avoid this you must to create a custom control and do the drawing in OnPaintBackground protected method. This seems a overkill. Or you can write to a Bitmap and put it in the BackgroundImage property.
I'm trying to write a simple GUI that renders a number of images using the Graphics' object primitives. What I want to have is a series of areas that I can paint to in isolation of the other areas, so that each painting "canvas" has it's own origin within the global coordinate frame of the top-level form.
So far I have tried adding several panels to a FlowLayoutPanel. However, they seem to be getting placed one on top of the other, as only one onPaint method is being called. I can override the Form's onPaint to invalidate the other panels, which are then painted, but not displayed.
Besides setting the sizes, and initialising the FlowLayoutPanel, is there something I'm missing? Is there a better way of doing this?
Code: http://pastebin.com/30Uf9AGF
based on the names of your classes, it looks like you are designing a game ... maybe you want to take a look at Microsofts XNA framework?
however, the problem with the code you provided is, your layoutPanel is not sized correctly, therefore its child-controls are not visible on the main form... since painting is only done for visible items ... there is no painting for most of your FloorDrawPanels ...
try changing the size of your layoutPanel or setting its dock mode to fill
You don't set the size of the FlowLayoutPanel. It will default to 200 x 100 with a Margin of 3. You fill it with controls that are 100 x 100. Given the margin, only one of those controls can ever be visible at the same time. It is therefore no surprise that you only ever get one paint event, Windows only asks visible controls to paint themselves.
Not quite sure what was intended, start by making the FLP bigger. And set its AutoScroll property to true so that the user can scroll the other controls into view. Using the designer would have been a quick way to find this out btw.
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'm pasting an image from the game im building.
the matrix of empty cells you see are made of PictureBox[][].
I wan't whenever I drop a coin to one of the columns... I want it to go down but the purple stuff will hide the falling coin and the gray color you see wont hide it.
How do I make this effect?
please notice that in each PictureBox control I have set the BG Image as you can see
Don't do it like that.
Create custom control. In custom control, override Paint, and then draw COIN sprite first, then draw mask over it. Be sure that you use double-buffered painting here.
It will work like a charm, trust me!
And, since you are (I gueess) building 5-in-a-row game here, your custom control will be able to paint occupied slots as well.
By designing custom control, you'll be able to hide all the animation and graphics stuff away from your main form.
I don't think it is possible like that. Controls in WinForms cannot be transparent, that is the problem
I would think in three directions:
Forgetting about controls and
painting everything OnPaint event of
the form. It is not too complicated
(well it would be more complicated
to detect some mouse events like you
did now, as you wouldn't know which
graybox is hit, but rather just
mouse coordinates)
Experimenting with coin as a form
(forms can be transparent)
Possibly using WPF with same logic
you did, as controls can be
transparent there
Controls in Windows Forms can be transparent. You need to set the TransparencyKey of the Form to some color that you never plan on using (many people seem to love/hate Magenta for this), and then set the BackgroundColor of each PictureBox to the same color. The result should be a transparent PictureBox with its Image drawn over it. I'm pretty sure this won't work with the BackgroundImage property, mind you- just the Image property.
One potentially unwanted side effect of this method is that you'll be able to see whatever's behind your form (the desktop, other application windows, etc.) through the transparent places in the PictureBox.