![]() ![]() Public override object ConvertFrom(ITypeDescriptorContext context, Public override bool CanConvertFrom(ITypeDescriptorContext context, Public class StringListTypeConverter : TypeConverter To define a TypeConverter to support binding conversion for a specific class, you have to create a class that inherits from TypeConverter, and overrides the ConvertTo or ConvertFrom and also the corresponding CanConvertTo and CanConvertFrom: WPF and Silverlight make extensive use of the TypeConverter in binding. The default type converters are in the System.ComponentModel namespace and are named TypeConverterNameConverter. Most native types have an associated TypeConverter. It uses InstanceDescriptor and System.Reflection to provide the information necessary to initialize a property at run time. The TypeConverter is used to convert values between data types, and to assist property configuration at design time by providing text-to-value conversion. In WPF, a TypeConverter can be used to reduce the complexity of interfacing a custom object in a ViewModel to a View. In this particular case, we will be providing conversion to and from a string. #Wpf colorconverter xaml how toThis article will show you how to implement a class that will provide type conversion for another class. The title indicates that this article is specific to binding to an object in WPF, but it is really about implementing a TypeConverter for a class. Then I thought: could I use this for binding in WPF to both a Text property and a ItemsSource property? It turns out that you can. Creating a TypeConverter for a collection from a delimited list made sense. Thus I was familiar with the TypeConverter, but had never implemented a TypeConverter. I could define a class with the proper types and then take string values and create a new instance of the class. In the application I was working on, I was using the TypeConverter class to convert values from string to specific types using Reflection. #Wpf colorconverter xaml fullYou can download the full source for this blog post: UniversalValueConverter.Basically what brought on this example was the need to convert a delimited list to a collection. I am guessing that type conversion within Silverlight is 'baked-in' to the XAML parser, which means that it is not possible to re-use this logic :-( Unfortunately Silverlight lacks the TypeDescriptor class which is used to obtain TypeConveters. FillProperty, new SolidColorBrush ( Colors. Which provides a more flexible mechanism for setting property values: rect1. The above converter really is swiss army knife for bindings, but what about code-behind? You are still constrained by the type requirements of the property being set: rect1. You can also use this converter to convert from string to their corresponding enum values, for example binding the string "Collapsed" to the Visbility property. ![]() For example, you can set the fill of a rectangle by simply specifying the named color: įor the first conversion, string to brush, you can use named colors, and the hex notation in its range of abbreviated forms (#AF7, #AAFF77, #FFAAFF77. One of the great features of the XAML language is that it is flexible, concise and expressive (yes, I know that XML can be a little verbose, but if you try to create a complex UI purely in code-behind I think you will agree with my observations!). This converter can be used both within bindings and in code-behind to give more concise property setters. This post provides a simple IValueConverter implementation that makes use of the framework type converters in order to convert between a large range of source / target types. ![]()
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