Definition of List dependency property in WPF XAML

Original: Definition of List dependency property in WPF XAML

List Content Properties

For example, a list header sort control, we need to define a list of headings so that the caller is free to set the header information.

When you customize a control, you encounter list dependency properties, so how do you define it?

Here's how the error is defined:

1///<Summary>2Identity< Seecref= "Headers"/>'s dependency property. 3///</Summary>4 Public static readonly DependencyProperty headersproperty = Dependencyproperty.register (5"Headers", typeof (List<headercontent>), typeof (Listviewheader),6New PropertyMetadata (New List<headercontent>( ), (d, e) = = ((listviewheader) d). Initheaderlist ()));7 8///<Summary>9 ///Gets or sets the information collection for the header. Ten //// because this is a dependency property, it is difficult to limit its non-null and always empty.  One///</Summary> APublic List<headercontent>Headers -     { -Get = (List<headercontent>) GetValue (headersproperty); the set = = SetValue (headersproperty, value); -}

As defined by the dependency property above,

• You must provide a default property of new list<headercontent>() or set the default list value when the custom control is initialized . Otherwise the interface calls this list property to add the item, the interface initialization will certainly error ~
• When displayed in XAML, some error messages are not reported ~ (although not affecting normal startup, but the list of errors has always been shown, for me with obsessive-compulsive disorder). Not tolerable)

The right Implementation plan

• To define a list dependency property:

1///<Summary>2Identity< Seecref= "Headers"/>'s dependency property. 3///</Summary>4 Public static readonly DependencyProperty headersproperty = Dependencyproperty.register (5 "Headers", typeof (Listviewheadercontentcollection), typeof (Listviewheader),6 New PropertyMetadata (Default (Listviewheadercontentcollection), (d, e) = = ((listviewheader) d). Initheaderlist ()));7 8///<Summary>9 ///Gets or sets the information collection for the header. Ten //// because this is a dependency property, it is difficult to limit its non-null and always empty.  One///</Summary> A Public listviewheadercontentcollection Headers -     { - get = (listviewheadercontentcollection) GetValue (headersproperty); the set = = SetValue (headersproperty, value); -}

• To define a list content collection class:

By implementing the ilist<t> and IList interfaces, you can have the list add content as a list when the interface is called.

Note: The implementation of the interface method to modify the content can be

1public sealed class Listviewheadercontentcollection:ilist<headercontent>, IList2     {3Private ReadOnly List<headercontent>_headcontents = new List<headercontent>();4Public IEnumerator<headercontent>GetEnumerator ()5         {6 return _headcontents.getenumerator ();7         }8 9 IEnumerator ienumerable.getenumerator ()Ten         { One return GetEnumerator (); A         } -  - Public void Add (headercontent item) the         { - _headcontents.add (item); -         } -  + public int Add (object value) -         { + _headcontents.add ((headercontent) value); A return _headcontents.count; at         } -  - Public bool Contains (object value) -         { - return _headcontents.contains ((headercontent) value); -         } in  - Public void Clear () to         { + _headcontents.clear (); -         } the  * public int IndexOf (object value) $         {Panax Notoginseng return _headcontents.indexof ((headercontent) value); -         } the  + Public void Insert (int index, object value) A         { the _headcontents.insert (index, (headercontent) value); +         } -  $ Public void Remove (object value) $         { - _headcontents.remove ((headercontent) value); -         } the  - void ilist.removeat (int index)Wuyi         { the _headcontents.removeat (index); -         } Wu  - Object Ilist.this[int Index] About         { $ get = _headcontents[index]; - set = = _headcontents[index] = (headercontent) value; -         } -  A Public bool Contains (headercontent Item) +         { the return _headcontents.contains (item); -         } $  the Public void CopyTo (headercontent[] array, int arrayindex) the         { the _headcontents.copyto (array, arrayindex); the         } -  in Public bool Remove (headercontent Item) the         { the return _headcontents.remove (item); About         } the  the Public void CopyTo (array array, int index) the         { + _headcontents.copyto ((headercontent[]) array, index); -         } the Bayi public int Count = _headcontents.count; the  the Public object SyncRoot {get;} -  - Public bool issynchronized {get;} the  the Public bool IsReadOnly {get;} the  the Public bool Isfixedsize {get;} -  the public int IndexOf (headercontent item) the         { the return _headcontents.indexof (item);94         } the  the Public void Insert (int index, headercontent item) the         {98 _headcontents.insert (index, item); About         } - 101void IList<headercontent>. RemoveAt (int index)102         {103 _headcontents.removeat (index);104         } the 106 Public headercontent This[int index]107         {108 get = _headcontents[index];109 set = = _headcontents[index] = value; the         }111}

Call:

Definition of List dependency property in WPF XAML