Walkthrough: A Custom Control in XAML isn’t a User Control
Catnip to developers is truly reuse. Redundant code is a source of continual agony to architects and maintenance developers alike. In XAML we have a few ways to reuse our code that aren’t just C# strategies like inheritance and static methods.
XAML Reuse Strategies
1. Higher Resources
The <Resources /> property of a page or control is within the scope of any child element. As a result, this raises the scope of styles, templates, and variables to more than one UI element. The Page resources property is the highest scope available in a single UI.
2. Resource Dictionaries
A resource dictionary is a file. It contains anything you can put in the <Resources /> property of a page or control. Since it is an external file, the contained styles, templates, and variables can be shared by unrelated controls or pages across the project.
3. User Controls
A user control is a layout container or group of controls that act (in a way) like a little bitty page. You can use and reuse a user control on the same page or across multiple pages in a project. A user control has code-behind and an event pipeline much like a Page does.
4. Custom Controls
A custom control is lightweight. It is sub-classing an existing control. For example (and in this demo) you can sub-class the Button. Sub-classing lets you inherit the functionality of the base and inject your custom behaviors into it. The resulting control remains a button. Developers interact with it like a standard button.
Creating a custom control
In the video above I build out a simple custom control sample. The code (or nearly the code) for the sample can be seen in my StackOverflow answer found here. Since I wrote the sample for the answer, I figured I would put together this blog article. I hope it was useful.
Best of luck
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