Weak |
Mediates an action event with two arguments, holding only a weak reference to the event sink.
Thus there is no reference created from the event source to the event sink, and the event sink can be garbage collected.
Inheritance HierarchyNamespace: Altaxo
Assembly: AltaxoCore (in AltaxoCore.dll) Version: 4.8.3179.0 (4.8.3179.0)
SyntaxC#
public class WeakActionHandler<T1, T2>
Type Parameters
- T1
- First action parameter.
- T2
- Second action parameter.
The WeakActionHandlerT1, T2 type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | WeakActionHandlerT1, T2(ActionT1, T2, Object, String) | Initializes a new instance of the WeakActionHandler class. |
| WeakActionHandlerT1, T2(ActionT1, T2, Type, String) | Initializes a new instance of the WeakActionHandler class for a static event. |
Properties| Name | Description | |
|---|---|---|
 | EventSource | Gets the event source. Attention! Use the returned value only locally, otherwise, you will get a dependence that you wanted to avoid. |
Methods| Name | Description | |
|---|---|---|
| Equals | Determines whether the specified object is equal to the current object. (Inherited from Object) |
| EventSink | Handles the event from the original source. You must not call this method directly. However, it can be neccessary to use the method reference if the implicit casting fails. See remarks in the description of this class. |
 | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object) |
| GetHashCode | Serves as the default hash function. (Inherited from Object) |
| GetType | Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object) |
| Remove | Removes the event handler from the event source, using the stored remove action.. |
| ToString | Returns a string that represents the current object. (Inherited from Object) |
Operators| Name | Description | |
|---|---|---|
  | (WeakActionHandlerT1, T2 to ActionT1, T2) | Converts this instance to an action that can be used to add or remove it from/to an event. |
Remarks
Typical use: (Attention: source has to be a local variable, not a member variable!)
Sometimes it might be neccessary to use explicitly the event handler method of this instance:
You can even maintain a reference to the WeakActionHandler instance in your event sink instance, in case you have to remove the event handling programmatically:
C#
source.ActionEvent += new WeakActionHandler<MyArg1,MyArg2>(this.EhActionHandling, x => source.ActionEvent -= x);
C#
source.ActionEvent += new WeakActionHandler<MyArg1,MyArg2>(this.EhActionHandling, x=> source.ActionEvent -= x.EventSink).EventSink;
C#
_weakActionHandler = new WeakActionHandler<MyArg1,MyArg2>(this.EhActionHandling, x => source.ActionEvent -= x); // _weakActionHandler is an instance variable of this class source.ActionEvent += _weakActionHandler; . . . source.ActionEvent -= _weakActionHandler;
See Also