ICustomTypeDescriptor, TypeDescriptionProvider, TypeConverter, and UITypeEditor
c#, customtypedescriptor, propertygrid, typeconverter, uitypeeditor
Solution
Tweaks:
`TypeDescriptionProvider`
- still replaces metadata (not extends)
- can also be added be `TypeDescriptor.AddProvider`
- can be applied per-type as well as per-instance, making it possible to apply to lists without having to implement `ITypedList`
`TypeConverter`
- for `PropertyGrid`, this is also the mechanism used to obtain metadata; note that `ExpandableObjectConverter` simply delegates to `TypeDescriptor.GetProperties`, but this is not always the case
- also responsible for re-creating immutable objects (such as structs) with changes
`UITypeEditor`
- also responsible for painting the preview box in `PropertyGrid`
Additional:
- `IExtenderProvider` - appends properties; this may be what you were getting confused with `TypeDescriptionProvider`
- `ITypedList` - broadly the twin of `ICustomTypeDescriptor`, but for lists; can be avoided by use of `TypeDescriptionProvider` and a non-object indexer on any `IList`, i.e. `public T this[int index] {get;}`
- `IListSource` - provides indirection between a data-source and the data; for example, a `DataTable` implements `IListSource`, returning `DefaultView` when requested
Problem
I'm trying to get an overall understanding of how you use ICustomTypeDescriptor, TypeDescriptionProvider, TypeConverter, and UITypeEditor to change how a PropertyGrid displays and interfaces with an object. Can someone tell me if this is right, or if I missed any major concepts or points? I'm really just trying to understand why and when you would use each class. ICustomTypeDescriptor - Implementing this interface in a class totaly overrides the native properties of a class and replaces them with the PropertyDescriptors returned by ICustomTypeDescriptor.GetProperties() TypeDescriptionProvider - Used to extend on the existing properties of a class - A TypeDescriptionProvider is appended to a class through a TypeDescriptionProvider attribute - The GetTypeDescriptor() method of the TypeDescriptionProvider returns an ICustomTypeDescriptor to be appended to the existing properties of the type. - A PropertyGrid will show both the properties of the class found through Reflection, and the properties added to the class through the TypeDescriptionProvider TypeConverter - Converts between types - In terms of using a PropetyGrid used to convert between complex types and primitive types that can be displayed/edited in the property grid. - The GetStandard values method of a TypeConverter can also be used to show a list of possible values in the propertygrid UITypeEditor - Defines a custom editor for manipulating a property of a complex type. - Associated with a property through an attribute. So ICustomTypeDescriptor an TypeDescription provider are used to add/change/replace entire properties of objects. TypeConverter and UITypeEditor are applied to individual properties and control how those specific properties are interfaced with.