I'm trying to figure out why setting a control's Image property on one form has no visible effect, while setting the same property of a control that belongs to a different Form works perfectly. My target form has non-default background color (it's all black with a white foreground color) and no border style. Setting the other form to the same color and border style does not affect its ability to display images. So what's wrong with my target form? What settings could I have tripped that make my image sets do nothing?
Turns out the problem was that I was initializing the form from within itself, so it had no suitable graphics context to give itself to display images on. Moving the form's field outside its own class to the main form solved the problem.
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I'm developing a WPF project where I need to validate textboxes on code-behind and then change the border color of those textboxes to some unknown color defined by the user configuration; the problem is that to overwrite the MouseOver effect I would need to set the value from XAML directly via ControlTemplate or Style.
Is there a way to get the current value assigned to the TextBox from XAML? Maybe binding it to itself?
I will appreciate any help you can give.
When validating a TextBox, or any control for that matter, it's common to use an adorner to display the validation error (in your case, setting the border color). You can have a look at an example here.
Using this method, you don't actually change the TextBox's border, but create a new visual layer on top of the TextBox that draws the new border around it. This is pretty much the way validations should be done in WPF, and it also solves your problem of having to deal with changing the TextBox's border value back and forth.
I am having an issue about buttons in silverlight on windows phone 7. My button has a background image, and as I press it, it goes white like all the buttons in wp7 by default. What I want it to do, is to change its background image to different one. I found topic that describes something quite similar, but regarding the button color Windows Phone 7 (WP7) Change a button's background color on click.
Problem is that whenever I adjust any of the basic styles (Pressed, Disabled etc), I can only change everything besides the background image, because when I change it for one style, it stays changed for all the rest of them.
How can I make button change its background image while going into Pressed state? And why cant I do it the way the above link says?
ImageButton for Wp7 http://silvergeek.net/2011/01/14/imagebutton-control-for-win-phone-7/
If its not exactly what you need it might give you some hints.
I want a button that
Displays an image with NO border, NO background, NO text
If I tab into the imagebutton, THEN it shows the background and border
Also if I hover over it, it shows the background and border
I've searched and I've tried so many different things, but nothing it exactly what I want. I've tried setting various properties on the button to make the background and border transparent, but it still shows up. I've tried a style with a custom control template. I'd rather not have to completely reinvent all the triggers etc to get the button to render on mouse over. The biggest problem with custom control template is that then I loose all existing functionality and I'm basically building a new control from the ground up.
Here is another link that came closest to what I wanted but it doesn't properly work for me.
How do you completely remove the button border in wpf? - BUT.... for some reason the hover effect gets stuck. One I mouse over the image and the button border draws, it stays stuck on until I click somewhere else.
Actually, you will want to override the control template. You're not "losing" any functionality (aside from the UI triggers).
Original/Default Template -- This is a good starting point... copy/paste that into you're XAML (wherever you want to style this button... ie Button resources, UserControl/Window resources, App Resources?). From there make your adjustments.
Another easy way is to use Expression Blend. You can easily create a new template based on the existing template, and the styling/authoring tools it provides are much better than hand-coding XAML (unless you're good at doing that).
As far as displaying an image instead of text, just set the image as the content. A Button is a type of ContentControl which means that it can house any type of content (Object).
I have a WP7 panorama application that uses a dark image for the panorama's background. The issue is when the device is set to light theme. The issue root cause is the Focus state transition animation for the TextBox sets the background color to transparent.
Since my panorama is always dark I'd like my textbox to always be white background.
First attempt set textbox background to white.
FAIL: transition changes background back to transparent when textbox gets focus.
Next attempt programmatically set textbox background to white on gotfocus.
FAIL: transition changes background back to transparent when textbox gets focus.
Next attempt override control template and change transition.
FAIL: never could get this happy with WP7, not sure if I used right version
Next attempt override control template using Blend 4.
FAIL: might have missed something but every state looked correct.
I see where lots of others are having this same problem but no here's exactly what you need to do so you don't trip up some minor detail.
If you can help us with a solution please do share.
Here's what I tried with Blend 4.
Opened my project in Blend 4, selected my textbox, right-clicked on it, chose Edit Template, and then Edit a Copy.
Here's where I'm not exactly sure what I need to do.
I went to FocusStates, and selected Focused. What I see in the preview pane looks like what I want. A nice textbox with a white background.
I look on http://msdn.microsoft.com/en-us/library/cc645061%28v=vs.95%29.aspx and I see there is a storyboard animation for the various FocusStates and I figure in WP7 there must be one that makes textboxes have a transparent background when they have focus in the light theme.
My goal of making my textbox have a white background since I have a panorama with a dark background image has proven difficult to say the least.
You were on the right path with this retemplating the control in blend. You can control formating of each constituent component of the control and for each state.
If you're still having trouble with this, post your resulting xaml for the TextBox in your question once you've made the changes.
Re your edit: Focused -> Grid-EnabledBorder-Background uses static resource PhoneTextBoxEditBackgroundBrush. You can change this to a local value then choose your colour.
I'm about to lose my mind here.
Why won't the checkbox control blend with what's behind it?
The question applies to all WinForms controls, but I'm using this as an example.
A picture is worth a thousand words:
And a few more words:
What's behind the CheckBox are colored PictureBoxes and a Button.
The CheckBox's BackColor is set to Transparent. But somehow it decides that that means it should share the BackColor of the containing Form (is that its idea of the illusion of transparency?).
Is this not possible in WinForms? I could swear I did this before.
UPDATE:
I just tried this:
On that form, set the CheckBox's BackColor to Transparent, then change the BackColor of the containing Form to some other color, and the CheckBox will match that BackColor. What the.......?
This is a side effect of controls being Windows windows. A window is responsible for drawing itself, the OnPaintBackground and OnPaint methods take care of that.
This rendering model doesn't support transparency well. There is support for true transparency by using layered windows. That's implemented by the video adapter, Windows uses it hardware overlay feature. But that only works for toplevel windows, not child windows. Note the Form.Opacity and Form.TransparencyKey properties.
There's partial support for transparency through a trick. A control can fake it by asking the parent window to draw itself first inside the control window. That produces the background pixels, it can then draw on top of that. Setting the BackColor property to Color.Transparent enables this trick for controls that support this. All of the ButtonBase derived classes do. But not controls that are wrappers for native Windows controls.
"Asking the parent window" is where the flaw in this trick becomes visible in your screen shot. You are seeing the form pixels. Stacking effects don't work, it never considers any intermediary window in the Z-order, only the parent. This is fixable but very ugly, there's a KB article that show the code.
Also notable is that WPF doesn't have this restriction. Controls are not windows, they render by painting themselves on top of the parent. Layers of paint. Transparency is now trivial, just don't paint.
Bob Powell has written an excellent article about transparent controls. Check it out:
https://web.archive.org/web/20141227200000/http://bobpowell.net/transcontrols.aspx
Can you set the backcolor of the checkbox manually to the color you want? (The value in the picturebox behind it)
'Transparent' may mean something different from what you want to MS.
Also, try changing the zorder of the pictureboxes (bring to front) and see if that changes the checkbox's underlying color.