In. net, event is a very useful feature, which allows us to easily implement callback. But it also has a lot of inconvenience: An event can only use the + =/-= Operator to increase or decrease delegate except the class that declares it, and cannot delete all delegate hanging on it at a time.
Program When the scale is small, it is easy to do. Once the program expands, it is very troublesome to find out the delegate hanging on an event. In particular, many classes have events, and many events are linked in different places. When determining whether an object is unnecessary, You need to promptly disconnect the delegate from its events.
The following function can directly empty all the events of an object, Code I will not explain it much: 1 /// <Summary>
2 /// Clears the delegate associated with all events of an object.
3 /// </Summary>
4 /// <Param name = "objecthasevents"> Objects with events </Param>
5 Public Static Void Clearallevents ( Object Objecthasevents)
6 {
7 If (Objecthasevents = Null )
8 {
9 Return ;
10 }
11
12 Eventinfo [] Events = Objecthasevents. GetType (). getevents (
13 Bindingflags. Public |
14 Bindingflags. nonpublic |
15 Bindingflags. instance );
16
17 If (Events = Null | Events. Length < 1 )
18 {
19 Return ;
20 }
21
22 For ( Int I = 0 ; I < Events. length; I ++ )
23 {
24 Try
25 {
26 Eventinfo EI = Events [I];
27
28 /* **************************************** ***************
29 * Each event of the class corresponds to a private delegate class with the same name.
30 * Member variable (this can be confirmed by reflector ). Because private
31 * Member variables cannot be modified in the base class.
32 * Events declared in class must be obtained from the declaringtype of eventinfo.
33 * The fieldinfo of the member variable corresponding to the event is modified.
34 **************************************** *************** */
35 Fieldinfo fi =
36 EI. declaringtype. getfield (Ei. Name,
37 Bindingflags. nonpublic |
38 Bindingflags. instance );
39 If (Fi ! = Null )
40 {
41 // Set the field corresponding to the event to null to clear all delegate hooks on the event.
42 Fi. setvalue (objecthasevents, Null );
43 }
44 }
45 Catch
46 {
47 }
48 }
49 }
50
51
