I am new to Silverlight, but I couldn't find anything about this when I googled it.
I have a button that I am trying to set the style programatically. I have the style defined in a XAML file and I want to pull the style into C# so I can dynamically create a button and assign it this style. So far, this is what I am trying:
button.Style = (Style)Resources["CloseButtonStyle"];
However, it just makes the button have no style. Is there an easy way to do this? I feel like this should be obvious, but I can't get it to work.
You are assuming that your Resources property on the current object is the one that contains the defined style. However, I assume, given the symptoms of your issue, that CloseButtonStyle is actually defined further up the control hierarchy.
Instead, you need to traverse your control hierarchy until you find the resource (or if you know the object that defines it, just refer directly to that object). Unfortunately, Silverlight doesn't include FindResource call like WPF, but it's not too difficult to implement your own.
I can call button1.Style = (Style)Resources["NonExistentKey"]; and it makes my button have no style at all as well, point being that the resource is probably not being found, you won't get an exception.
You directly access the Resources property, but is the style really in the immediate resource dictionary of your Window/UserControl/whatever-you-have?
Related
From this document:
http://www.telerik.com/help/silverlight/radmaskedinput-features-extensions.html
I am interested in <telerik:RadMaskedNumericInput maskedInput:MaskedInputExtensions.Maximum="1000" />
But in their examples they are setting a property like MaskedInputExtensions.Maximum directly in the XAML. So if I want to use it I have to go to go to all my XAML files and set it there.
But since I have created my own control so I have both a CS source code for it and also my own XAML for the style of my control.
Is there a way I can set it in either of those places to make it more reusable?
The best way to do it is using styles.
Check this out.
http://blogs.msdn.com/b/pakistan/archive/2013/03/07/xaml-how-to-style.aspx
http://www.codeproject.com/Articles/180656/Styles-in-Silverlight
It means that you have a pre-defined style for every element of a certain type, so if you want to change the same property for every element of that kind you just change this specific style.
If this is not what you want you can also create a property called "Maximum" for example and bind it to your controls manually. Once you change this property it will reflect on your controls.
Hope it helps!!
I'm using a 3rd party control (in this case, Telerik's RadChart control), which has a complex inner ControlTemplate that encompasses several elements of the chart. Unfortunately, not all parts are exposed explicitly for me to style, and I find myself wanting to set a property on a particular sub-element inside the ControlTemplate, either via XAML or via code. After struggling with the XAML for a while, I settled for a code-centric approach, but I'm still stuck.
Using Snoop, I can see that the top-most ChartArea control (which I can access) renders an AxisX2D object named PART_AxisX, which in turn has a template which contains the PART_AxisLabels object, which is the one I need to style. (Incidentally, the property I want to set is AlternationCount, but I couldn't find a less hacky way of getting to it).
I tried to use the ControlTemplate.FindName method (as shown here) to get the AxisX2D object, and then again on that object to get the AxisLabels object, but FindName always returns null:
var chartArea = myChart.DefaultView.ChartArea;
var visualAxisX = chartArea.Template.FindName("PART_AxisX", chartArea) as AxisX2D;
even though Snoop confirms that chartArea is, in fact, the AxisX2D's TemplatedParent. I checked in the debugger and I could find PART_AxisX in chartArea's internal Template property.
So my questions are:
1) What am I doing wrong here?
2) Is there a better way to approach this that isn't as roundabout as this?
The solution is to wait till after the Loaded event has occurred on the Control.
When this event has occurred you know that the Template has been applied and the visual tree has been built for the control, and so you can then access the elements using FindName.
http://blogs.msdn.com/b/mikehillberg/archive/2006/09/19/loadedvsinitialized.aspx
Slightly related link given here for case when using a Content Template on a ContentControl.
Why would 'this.ContentTemplate.FindName' throw an InvalidOperationException on its own template?
I wanted to know which one amongst Style and UserControl would be better to use in WPF?
For example:
I have created an image button in two different ways.
One uses Style and ContentTemplate property is set.
It uses one other class with dependency properties.
The other way is I have created a UserControl which has a button and its content property is set.
The file UserControl.xaml.cs also contains the dependency properties.
For Code details see the answers of this question:
Custom button template in WPF
Which one would be better to use? In which scenario should one go for Style or UserControl or any CustomControl?
Styles are limited to setting default properties on XAML elements. For example, when I set the BorderBrush , I can specify the brush but not the width of the border. For complete freedom of a control’s appearance, use templates. To do this, create a style and specify the Template property.
Styles and templates still only allow you to change the appearance of a control. To add behavior and other features, you’ll need to create a custom control.
For example,
To create a button like a play button use styles and templates, but to create a a play button which will change its appearance after pausing it use UserControl.
For this type of thing I would go with Style, even though I'm not really adept with graphical tools. I tend to produce a basic, boring style that I can get started with and then prettify it once the application functionality has been verified.
The nicest thing about WPF is being able to distance much of the graphical look, feel and behaviour away from the code.
This allows you to change the style of your application without revisiting the code and indeed means that you can change styles on the fly at runtime.
There is an awkward line to tread with regards to how much behaviour is placed within the XAML and how much is placed within the code. A rough guide would be to decide on what behaviour must always be present within the UI and place that in the code, everything else place within the XAML.
Think of the code as being an abstract class with defined interfaces and the XAML Styles as being classes based on that class and you'll get an idea of what I mean.
Conversely, I know that people who are far more adept at the GUI work prefer to put more functionality in the XAML and others who prefer the code side, because they find the GUI work slow or difficult.
When thought of that way you'll see that there's never really a right or wrong answer, just better solutions that suit your skills.
if a style is used, it can not be modified agaign. so i need a clone method. but its hard to implement.
what i want to do is implementing a cascading 'style' mechanism. for example, i set two style to the same frameworkelement. the same property of latter style will override the former one, while the different property remain unchanged.
but if i set the style property of the frameworkelement twice directly, the 1st style will be gone. so i use the baseon property of style class to do that. but now come across another problem, the style can not be modified after it's been set to a frameworkelement.
so now i need a clone method.
Kevin,
I have written a CloneObject class which is exactly what you are looking for. Check out my code here:
"Generic class for deep clone of Silverlight and C# objects".
Jim
thanks jim. i finally discards this 'clone' idea, because it's not that easy and seems to produce some buggy problem. so i try to create a xaml resource file, and every time i need to create a instance, i just load the xaml and call the XamlReader.load.
this can bring some performance issue, but i think the cost is acceptable. and i can do styling job in blend for that specified xaml file.
I try to use inheriting in WPF. I have asked a question about this earlier, but no one answered correct. So I try to make a BaseWindow class with some UI elements and I want that other windows, that inherit my BaseWindow would have these UI elements. How to do that. My practise with WinForms applications dont work anymore. Maybe there are some simple examples or smth..? Thanks
If you want to inherit from a window, you need to create an implementation of a window in code only, and you can then inherit from this - note that your Window declaration in the XAML would need to change to point to this code, e.g.
<src:BaseWindow xmlns:src="clr-namespace:BaseWindowNamespace" ...>
If you define the base window using XAML, you'll get the following errors:
"'WpfApplication1.Window1.InitializeComponent()'
hides inherited member
BaseWindowNamespace.BaseWindow.InitializeComponent()'.
Use the new keyword if hiding was
intended"
"BaseWindowNamespace.BaseWindow cannot
be the root of a XAML file because it
was defined using XAML"
Now, at this point, I must point out that this is counter to the way that you should handle composition of your window. The "standard" way of doing this would be to use content templates to display user controls which could be swapped and styled to achieve different looks and functionality. In this way, the function of the window becomes that of a harness, and you can achieve a clean separation of content which can be easily implemented using MVVM.
Did you try the BasedOn tag? I don't know about windows, but that's what you use for UserControls AFAIK.