I am using c# winforms to show an Image. The displaying of the image is done using a user control. Now I want to provide the user to draw lines, put other small images, write text etc over the image on an overlay control. How can I provide this functionality? If I use another user control to show the overlay control with transparent back, will that work?? any other solution will be welcome.
You might try approaching this with a canvas (Panel) that handles painting the image as the background and all the annotations/markup afterwards. This will make the foreground appear to be transparent. I expect you'll want to set Control.DoubleBuffer for performance.
You might experiment with setting the style ControlStyles.AllPaintingInWmPaint. Also, try overriding Control.OnPaintBackground and do nothing, and override Control.OnPaint and do all your painting inside there.
If performance is still unacceptable, pay close attention to the PaintEventArgs.ClipRect property. This is the only area you need to paint. The trick is figuring out which of your annotations/overlays intersect with this rectangle and painting them in the correct order.
Either this canvas or a higher level control will need to track mouse movement so you know where to draw the lines, paste images, etc.
Related
I'm looking to add a 'mapview' type control to my project.
It must have a 'main map' image with clickable transparent rectangles with borders and icons/images that can be animated when an event occurs.
What would be the best way of achieving this using windows forms in C#?
My first thought was to use a picture box with other items on top of it but I might run into problems with transparency etc.
Are there any libraries or anything out there that would be able to achieve this?
No need for a library, really:
I would go for a regular doublebuffered Panel subclass or even a PictureBox subclass for the board/map along with a movable Label or Panel subclass fpr the rectangles/items.
Important: Make sure the Labels are not just 'put on top' of the PictureBox but really nested!! (lbl.Parent = pbox). Then transparency will work just fine..
Since PictueBox is not a 'container', to nest a control in it you need code. But since you probably want to create them dynamically this is not an issue anyway.
This assumes that the rectangles are not overlapping! For overlapping controls transparency in winforms will not work.
The clearer you understand the 'animate when event' part the easier the rest of the code will be..
Since you mention 'animation', a word of warning: Simple animation, especially in reponse to a user action is doable; for more classy animation you may run into the limits of winforms.
Hello,
Above is the program I am writing. On the right panel is basically two custom controls (the blue rectangle area) I created and just added them as controls to the background panel control when this winform program loads.
I used MS paint to draw out the pop up balloon that I want to see when my mouse enter this control's area. I want to do the following:
1. If mouse enter the control area, the yellow area balloon pop up and populate with the information of that specific control
2. If mouse move out of the control area, the pop up balloon disappear.
Can this be done with Winform application? I looked around and found out about Tooltip class but so far from researching I don't know if it does what I want to do.
I could be wrong but googling around gave me the impress that Tooltip offers very little in term of style. Ideally I want to make this pop up balloon into almost like a border-less pop up window where I can put image , font ect.....at will. Also Tooltip works if you hover over a button or specific field whereas I want the entire control area.
Can this be done? I appreciate if you can point me to any work around if there is one.
I wrote a comment, but I figure I'll expand it into a full answer. This is assuming you want a new control, which isn't a tooltip, for maximum customizability. I did something similar to this for work recently, to act as a non-modal info popup that disappears when clicked.
Creating a Custom Popup Form
What you want is essentially a floating popup that appears over your form, which means you'll want to define a new Form object, rather than a UserControl, as it won't actually be embedded within your other form.
Give it a multiline, non-editable textbox that you can fill with the information you want to populate, then simply call a new instance of the form on your Mouse_Enter event. Close it upon Mouse_Leave.
Adjusting The Style
You'll have to play with it a bit to get it to actually act like a popup and not just a window. I'd recommend setting it to a non-modal popup, and removing the border. You can write a function to automatically size it to its contents. I don't imagine you'll want the user manually resizing it.
Some other things to look into would be overriding the CreateParams property that comes with the basic Form object. You can force DropShadows and TopMost forms without making the form modal. Overriding ShowWithoutActivation to always return true will prevent the form from stealing focus when it pops up.
I'm not sure if you can pull off rounded edges like you have in your mockup. Perhaps you can pull it off with some wizardry in the OnPaint() function, but I couldn't tell you how to do it.
It might be a bit of a pain for fiddling around with, but you can get some good functionality and appearance out of it. If you think you can pull it off acceptably with the ToolTip class, go for it. It took me about a week to get my notifications where I wanted them (though I added several features that you probably don't need to worry about).
Examples
Some keywords to look up in related searches would be Toast Notification and Non-Modal Popup. This might be some use:
http://www.codeproject.com/Articles/442983/Android-Style-Toast-Notification-for-NET
Since you already have implemented custom user controls you might want to try it again. Make a control that is that style and color, changes it's size based on it's text. You can feed it information (such as the text to display) from your existing user control object. You can also have the mouse enter/leave code reside in your first user control.
If you're not sure how to make a rectangle with round corners you can either make it on the fly using a graphics object (which will turn into a bitmap on the screen) or make it how you want it to look in GIMP (or photoshop if you have it) then use that image as the background on your user control. Make the default background transparent (so your voids above the round corners are not grey). If you make a pre loaded image you'll need to be aware you will only be able to scale it equally in Y and X directions. unequal scaling will make it look distorted.
Can you use the Mouse_Enter event on the control?
The scenario is that i want the user to create a shape in a small panel that opens (the added shape can later be placed on the canvas), but for a better reference, i want the user to be able to move the semi-transparent panel somewhere on the canvas and then draw with the accurate reference.
Please tell me:
Which panel type to use
How to make it moving by clicking the mouse on the move button (not the whole panel as dragging will be used for drawing lines) and move it around.
How to make it semi transparent.
How to make it appear and disappear (this should be pretty simple)
How to somehow limit its movement inside the canvas so it cannot move on the ribbon
And I really really hope there will be something built-in in WPF that i'll be able to use, and i will not have to do it the hard way i.e. create a rectangle, and do customized hit testing on it to allow the user to draw on top of that rectangle, make that rectangle transparent, and add graphics items for the buttons and controls on that rectangle "panel".
I am asking this because i have never seen such feature in any Windows application and i have no idea what to use for this purpose and how to implement it. The closest thing to what i want is in Adobe Acrobat Pro, which is the small preview of the page that appears when i double click with the middle mouse button. It doesn't move, nor it is transparent or can be drawn upon, but scale and shape wise i want something similar.
You should be able to place a second Canvas inside of your main canvas, and place whatever UserControl you'd like with your "view" inside of it.
You'll have to handle the mouse click/drag for moving it around yourself, but otherwise, it should be very straightforward.
I´m using WinForms. I want to make a little class, which modifys controls to show it´s working.
I want to draw an overlay over for example a button. It should be a half-transparent gray.
After that i want to draw a ProgressBar on over it (in the center). Similar to This, except using a progress bar.
How can i realize this? I don´t want to set the position of the progressbar, just drawing it on the other one.
How could i do this?
Thanks :)
I have done something similar before.
You need to use Button.DrawToBitmap(Bitmap, Rectangle) to get the image of the button. Then make the Bitmap grayscale (there are multiple algorithms available for this; I have used the last one successfully although probably not originally from this site).
Now, I did this with an entire form instead of a button, but I disabled the form, and then covered the entire form with an image of itself, altered and then covered it with the progress bar (itself in a panel with other controls).
You could just as easily disable the button, cover it with a panel containing the image and the progress bar on top of it.
I have a Control that can overlay multiple C# user controls in my GUI. This control has a semi-transparent background in order to 'grey-out' portions of the GUI and the class looks somethink like this:
public greyOutControl: UserControl
{
// Usual stuff here
protected overide OnPaint()
{
paintBackround();
base.OnPaint();
}
}
Currently the control sometimes gets caught in a loop and constantly re-draws the background, making the semi-transparent color appear less and less transparent.
My idea to combat this is the following (in broad terms):
1) Determine what controls the greyOutControl is on top of
2) call Refresh() on those controls to update the display
3) continue drawing the greyOutControl.
My question is: How can I determine which controls the greyOutControl overlaps?, or is there a way that I can refresh only the part of the GUI that greyOutControl covers?
Why don't you keep track of your transparent controls and paint them after all the other controls are drawn?. Painting anything at the top of the Z-order shouldn't cause the other controls to be repainted.
I don't see a direct way of finding the overlapping controls. I think you might need to check the whole control tree to find out that. About refreshing, you can use Control.Invalidate(Rectangle) method to specify which part to refresh.
The solution to this problem I found was to programmatically take a screen shot of the area being overlayed and then use that image as the background for the control being overlayed. This then allows you to put the alpha overlay into the image within the OnPaint() method and the control to draw itself correctly.
This does have the disadvantage that the background isn't updated in the overlapping control, but unless there was a number of event handlers watching if something changes and then update the overlayed control I cant see any way around the issue. Sometimes I regret not trying to use WPF!