Xaml custom typeconverter

Resources are objects that are created the object is rendered by XAML parser. Every FrameworkElement object has a ResourceDictionary object placed within it. You can add Resources within this ResourceDictionary and can reuse those component within the scope.

Resources are reusable component which one can use for several times to produce its output. So if you need an object that you want to reuse more than once in your application, and you don't want the object to be changed within the scope, Resources are then the best option for you. This object can be reused any time when required. You can assign various resources to this Collection which you would use in different object created within the scope of the object.

StaticResource finds the key defined within the ResourceDictionary under its scope during the Loading of the application. Hence the Compiler will throw error during compilation if not found in resources. On the other hand, DynamicResource Markup Extension defers the resource assignment to the actual runtime of the application. So the expression remains unevaluated until the object being created. Note : If the resource is derived from Freezable immutable , any change to the object will change the UI regardless of whether it is a StaticResource or DynamicResource.

Example : Brush, Animation, Geometry objects are Freezable. Binding is the most important and complex Markup extension which might be used to bind one object. It provides Databound object when the data object is assigned to the DataContext of the object. Thus say you have an object Obj which has several properties like Name, Age etc. Then you might write. Binding has lots of flexibilities, thus you can specify expressions on the databound objects and hence made it one of the most complex Markup extension.

As both of them are bound any change to the property automatically reflects the changes to the other textbox. StringFormat creates formatting of the string. We can have Converters associated with a binding to enable us to return appropriate value based on the value we feed in.

In case of binding, you must also make sure that the object which is bound to have implemented INotifyPropertyChanged. Otherwise every binding will work as OneTime. RelativeSource is a MarkupExtension which you have to use within Binding. This Markup Extension allows you to give Relative reference to the element rather than absolutely specifying the value. RelativeSource comes handy when absolute Reference is unavailable. My vote of 5 Gary Wheeler Jan Many thanks. Your examples were much clearer than those in the MSDN.

Software Zen: delete this;. My vote of 4 Christian Amado Aug Christian Amado. Re: My vote of 4 Septimus Hedgehog Aug Septimus Hedgehog. Thanks Clifford. The job I started three weeks uses an app that is exclusively WPF and there are more type converters than there are grains of sand on a beach.

I don't understand much about them being a WPF noobie but your article simplifies the concepts for me in chunks I can understand. Thanks a lot for sharing. Re: My vote of 4 Clifford Nelson Aug Clifford Nelson. I am glad it was helpful. I was wondering if there was something that you see that could have made the article better. Clifford, I'm a noob with WPF so anything that explains things in easy-to-digest explanations can only help me leaps and bounds.

As this is not possible directly, we'll use IValueConverter Interface and implement that in a user-defined class. That class will be used as a local resource in XAML code. To learn about a local resource, you can go through this article.

Our control Binding property will consume this local resource. Note - You need to use Windows. Data namespace in order to use that interface. Select first one, i. Two functions will be added to the class with the names -. Now, we have to write the definition of these two methods. But before that, we must understand what we are going to do in both the methods. Don't forget to build your project, otherwise you'll see an exception in designer like this.

Our project setup and resources are ready. Next step is to bind the IsChecked property of Checkbox with the string of the textbox. However, if you use this approach, you may find that some of your properties can't be edited. Yet examples abound of non-simple editing via the grid, such as colours, enumerations and image selection to name a few.

By making use of the TypeConverter and UITypeEditor classes, you can quite easily provide the ability to create richer editing support for your objects. This first article in this series will detail how to use TypeConverter allowing complex objects to be edited as though they were simple strings. As with most of my articles, I'm starting with a real world example and a solid required. I need to store units of measurement, so for this I have a simple class that has a pair of properties describing a given measurement.

A fairly standard class that simply has two properties along with a default implicit constructor. I'm also overriding ToString , as it's useful both for debugging purposes and for having something other than CustomTypeConverter1.

Length displayed in the PropertyGrid. And for the purposes of this demonstration, I have created a sample class which has three length properties. Isn't that an ugly enum? For this example, it will suffice, but there is another article which describes an alternative approach. I've set up a sample project which binds an instance of our SampleClass to a PropertyGrid , with the Length1 property pre-set to 32px.

When you run this project, you are left with a very unsatisfactory editing experience as you can't edit anything. The TypeConverterAttribute allows you to associate your class with a type that can handle conversion of instances of your type to and from other objects. You can only have one occurrence of this attribute per type.

As with a lot of these types of attributes, you can provide the conversion type one of two ways:. Here, we pass in a type object, meaning the type has to be directly referenced by your project and distributed as a dependency. Another alternative is to use a direct string, as shown above.