I have a picturebox where I change the BackgroundImage frequently. I have a the BackgroundImageLayout set to Zoom.
The problem is that when an image does not have the same scale as the picturebox, the picture is drawn in the middle. That is, the top and the bottom padding of the picturebox is always the same.
I would like for the BackgroundImage to always be aligned at the top. What is the easiest and most performance efficient way of doing this?
I can add that I download the images from the internet. If you think that the best way to deal with this is to resize them at that point I can do that :)
By far the simplest solution is to just change the Size property of the picture box so that the image can be drawn without padding. Implementing your own Paint event handler is possible too, not exactly necessary here I presume.
Related
when I use an image to a URL in my picture box I have black in here
Image = http://prntscr.com/cx1nre
I am known it's because my panel is on Highlight but when I use " Transparent " it give me a black in my picture box... example = http://prntscr.com/cwu9ev
Anyone can help me please?
After understanding your question (one picture over other and the top with transparency), your problem is how .net transparency works, it's not real transparency, it copies the background of the container.
So, to make it work instead of two picture boxes add a panel and a picturebox inside the panel, set the backgroundimage of the panel to the image you wanted to use, and then set the overlay image on the picturebox. As .net copies the container's backgrond, as you added the picture box as a child of the panel the picture box will copy the image and the transparency would work as you expected.
Only caveat is that you need to load manually the image, but there are plenty of examples on how to load it.
Also, there's even a better approach: instead of two pictureboxes just add one, load into a Bitmap the background you want, retrieve a Graphics object from it, draw the second image with Graphics.DrawImage and then use the bitmap as the Image for the picturebox. It's more complicated but it's the most efficient way to do this.
I have an array of picture boxes that are arranged in a square. I want to put a larger, mostly transparent picture box over the top. But when I do it covers the other picture boxes and just draws the background of the form.
Is there a way to get it to have all the other picture boxes show where it is transparent?
Transparency in WinForms isn't great. Some controls have transparency support, others don't. Some controls can be subclassed to enable this (by calling Control.SetStyle() with the SupportsTransparency flag). I believe this can be done with PictureBox.
However, transparency in all WinForms controls works by having the transparent control call its parent control to draw the background before the child control draws. This means that you cannot have two sibling controls and expect transparency on one to show through to the other. Sorry!
All that said, it would be possible to code your own workaround to support this. It would involve subclassing PictureBox and clever coding in the OnPaint override to locate sibling controls and manually trigger painting of them into in-memory bitmaps. Lots of gotchas with this approach.
Try WPF!
Here's a tip to get the desired result:
Create multiple copies of your top image.
Add each copy to the Controls of each picture box it should cover.
Adjust location of each copy according to the offset of each picture box to be covered.
So you will see every copy of your big image covering each picture box as if they were a single image.
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 have a picture in jpg format and size 765X368.
I need to use this picture for button and pictureBox on my form.
When I use for pictureBox I use Sizemode = StretchImage and I see it excellent, but when I use it for my button, it's very big and bad!!!
How I can make smaller this picture (automatic) when I load it to my button?
You could resize your image on the fly before using it in your button. See a code sample at http://snippets.dzone.com/posts/show/4336 .
Experiment with other options of SizeMode for button. In general it's always better to have two different images for a full view and for a button.
One more tricky thing about buttons is that they tend to... move the picture a little bit to the left or to the right, and it all looks not the way you would like it.
I am trying to make simple app that allows one to compare image to transparent PNG templates, by dragging the template over picture. For this I need a way to create a PictureBox that will contain the PNG image and be transparent where the the png is transparent.
Everything works fine but the transparency part: When I load a PNG image to the PictureBox (background color is set to transparent) it shows the background color of the containing panel rather than the image that it hovers.
I searched but only found a way to make the PictureBox completely transparent.
It is difficult to make a control that is partially transparent.
What you should do is handle the lower PictureBox's Paint event (the one that does not need to be transparent), and draw the overlay image using e.Graphics.DrawImage(image, x, y). This will draw transparent and semi-transparent images correctly.
EDIT: In response to your comment, there's nothing wrong with calling the Invalidate method in the MouseMove event. However, you will notice some flickering. To solve the flickering, make a control that inherits PictureBox, and call SetStyle(ControlStyles.DoubleBuffered, true) in the constructor.
This works fine if you add the pictureBoxOnTop to the list of controls of the pictureBoxToBeHovered to be hovered.
pictureBoxToBeHovered.Controls.Add(pictureBoxOnTop);
pictureBoxOnTop.BackColor = Color.Transparent;
pictureBoxOnTop .Location = new Point(0,0) ;