Removing All instances of specific delegate from multicast delegates

Question

Note: I'm writing this to have documented answers on my question because I frequently find myself having to manually research this

I'm looking for an efficient deterministic way to remove all instances of a delegate from a multicast delegate. Take tis code for example:

 Func<int> outputProvider = null;

 Func<int> valueProvider1 = () => 1;
 Func<int> valueProvider2 = () => 2;
 Func<int> valueProvider3 = () => 3;
 
 outputProvider += valueProvider1; 
 outputProvider += valueProvider2;
 outputProvider += valueProvider3;
 outputProvider += valueProvider3;
 
 outputProvider -= valueProvider3;

 var value = outputProvider.Invoke();
 Console.WriteLine("Value: " + value);

Even though I removed provider 3 the output is still 3, is there a simple way to remove all instances of a delegate?

@Charlieface oops copy error thanks for bringing it to my attention — johnny 5, Mar 02 '21 at 23:57
Use https://learn.microsoft.com/en-us/dotnet/api/system.multicastdelegate.getinvocationlist?view=net-5.0 to examine the set of delegates yourself? — Jeremy Lakeman, Mar 03 '21 at 00:01

score 1 · Accepted Answer · answered Mar 03 '21 at 00:05

1

Pretty self-explanatory:

outputProvider = (Func<int>) Delegate.RemoveAll(outputProvider, valueProvider3);

answered Mar 03 '21 at 00:05

Charlieface

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Removing All instances of specific delegate from multicast delegates

1 Answers1