Delegate Action does not take 3 arguments

Question

Action showTasks = (String name, String gender, String id) =>
        {
            StringBuilder stringBuilder = new StringBuilder();
            stringBuilder.Append("Name: " + name);
            stringBuilder.Append(System.Environment.NewLine);
            stringBuilder.Append("Gender: " + gender);
            stringBuilder.Append(System.Environment.NewLine);
            stringBuilder.Append("Id: " + id);

            var builderGoogle = new AlertDialog.Builder (this);
            builderGoogle.SetTitle ("Logged in");
            builderGoogle.SetMessage (stringBuilder.ToString());
            builderGoogle.SetPositiveButton ("Ok", (o, e) => { });
            builderGoogle.Create().Show();
        };

How can I pass 3 input parameters to delegate Action?

Actually just use var. var showTasks =.... let the compiler deal with the rest. — TomTom, May 12 '14 at 09:35
@SriramSakthivel, Yes it can, because types are explicitly mentioned, the compiler can infer type from usage. — Hamlet Hakobyan, May 12 '14 at 09:37
@HamletHakobyan What do you mean? How on earth compiler know you mean `Action` or `SomeOtherAction` Or `NonGeneric(string, string, string)` delegate? I will agree with you if OP used `new Action(()=> ...)` — Sriram Sakthivel, May 12 '14 at 09:39

Sergey Berezovskiy · Accepted Answer · 2014-05-12T09:40:45.653

Use Action<string, string, string> instead of Action.

Remember - there is set of Action delegates. All these delegates encapsulate methods which don't return value (i.e. have void return type). But void methods have different number of input parameters. Thus there is 17 different Action delegates, which encapsulate methods with different number of input parameters (from 0 to 16);

Action
Action<T1>
Action<T1,T2>
Action<T1,T2,T3>
...
Action<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>

So, you should pick appropriate delegate

score 5 · Answer 2 · edited May 12 '14 at 09:36

5

Use the Action<T1, T2, T3> delegate:

Action<String, String, String> showTasks = (String name, String gender, String id) =>

edited May 12 '14 at 09:36

Hamlet Hakobyan

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answered May 12 '14 at 09:35

Patrick Hofman

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score 3 · Answer 3 · answered May 12 '14 at 09:36

3

Change your type:

Action<string, string, string> showTasks = ...

answered May 12 '14 at 09:36

Yuval Itzchakov

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Delegate Action does not take 3 arguments

3 Answers3

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