How to remove a method from a delegate

Questions & Answers
1

I have added one method into a delegate, but i’m unable to remove it.

The code I’m using:

public delegate void 	MyDelegate();
static public MyDelegate delegateInstance;
    
void Start () {
    delegateInstance = new MyDelegate(MyMethod);
    delegateInstance -= new MyDelegate(MyMethod);

    delegateInstance();
}

I suppose it would not run the MyMethod, because it was removed before I call the delegate. Yet it ignores my try to remove it.

2

on your code you’re not adding an event to be called by the delegate youre just setting the reference, that’s why it won’t work with the “-=” operator.
try this(i’m not sure if it’ll work):

public delegate void MyDelegate();
static public MyDelegate delegateInstance;
 
void Start () {
delegateInstance += new MyDelegate(MyMethod);
delegateInstance -= new MyDelegate(MyMethod);
 
delegateInstance();
}

to just remove the delegate reference set it to null and do a null check

delegateInstance = null
if( delegateInsatance != null )
     delegateInstance();

for more info about events access
http://msdn.microsoft.com/en-us/library/aa645739%28v=vs.71%29.aspx

3

You are trying to remove a different instance than you originally assigned, so it doesnt do anything. You dont need to create a new MyDelegate object when assigning, you can just give it a method that fits.

public delegate void    MyDelegate();
static public MyDelegate delegateInstance;
 
void Start () {
    delegateInstance += MyMethod; // using += allows it to call multiple methods
    delegateInstance -= MyMethod;
 
    if (delegateInstance != null) // you should null-check delegates
        delegateInstance();
}

Using += will allow you to do something like this:

public delegate void    MyDelegate();
static public MyDelegate delegateInstance;
 
void Start () {
    delegateInstance += MyMethod;
    delegateInstance += MyMethod2;
    delegateInstance += MyMethod3;
    delegateInstance -= MyMethod;
 
    delegateInstance(); // will call MyMethod2 and MyMethod3 but not MyMethod
}
4

Rather than using Remove() or RemoveAll() static methods of Delegate class , you can use -= operator which has been overloaded for the same methods.