Mono Class Library: System.Delegate Overview | Members

System.Delegate.Target Property

Gets the last object upon which a delegate invokes an instance method.

public object Target { get; }

Value

A object instance, or null if the delegate invokes only static methods.

Remarks

This property is read-only.

If the delegate invokes only static methods, this property returns null . If the delegate invokes one or more instance methods, this property returns the target of the last instance method/target pair in the invocation list.

Example

Example 1:

The following example gets the Delegate.Target property values for two delegates. The first delegate invokes a static method, and the second invokes an instance method.

C# Example

using System;
public delegate string DelegatedMethod(string s);
class MyClass {
  public static string StaticMethod(string s) {
    return ("Static method Arg=" + s);
  }
  public string InstanceMethod(string s) {
    return ("Instance method Arg=" + s);
  }
}
class TestClass {
  public static void Main() {
    MyClass myInstance = new MyClass();
     //Create  delegates from delegate type DelegatedMethod.
    DelegatedMethod delStatic = new DelegatedMethod(MyClass.StaticMethod);        
    DelegatedMethod delInstance = new DelegatedMethod(myInstance.InstanceMethod);
    object t = delStatic.Target; 
    Console.WriteLine ("Static target is {0}", t==null ? "null":t);    
    t = delInstance.Target;
    Console.WriteLine ("Instance target is {0}", t==null ? "null":t);
    }
}

The output is

Static target is null
Instance target is MyClass

Example 2:

The following example gets the Delegate.Target property value for three delegates created using instance methods, static methods, and a combination of the two.

C# Example

using System;
class MyClass {
  public static string StaticMethod(string s) {
    return ("Static String " + s);
  }
  public string InstanceMethod(string s) {
    return ("Instance String " + s);
  }
}
class MyClass2 {
  public static string StaticMethod2(string s) {
    return ("Static String2 " + s);
  }
  public string InstanceMethod2(string s) {
    return ("Instance String2 " + s);
  }
}
public delegate string DelegatedMethod(string s);

class TestClass {
    public static void Main() {
    DelegatedMethod delStatic = new DelegatedMethod(MyClass.StaticMethod);
    DelegatedMethod delStatic2 = new DelegatedMethod(MyClass2.StaticMethod2);
    
    MyClass myInstance = new MyClass();
    DelegatedMethod delInstance = new DelegatedMethod(myInstance.InstanceMethod);

    MyClass2 myInstance2 = new MyClass2();
    DelegatedMethod delInstance2 = new DelegatedMethod(myInstance2.InstanceMethod2);

    Delegate d = Delegate.Combine(delStatic, delInstance );
    Delegate e = Delegate.Combine(delInstance,delInstance2);
    Delegate f = Delegate.Combine(delStatic, delStatic2 );
    if (d!=null) {
        Console.WriteLine("Combined 1 static, 1 instance, same class:");
        Console.WriteLine("target...{0}", d.Target == null ? "null" : d.Target);
        foreach(Delegate x in d.GetInvocationList())
            Console.WriteLine("invoke element target: {0}",x.Target);

    }
    Console.WriteLine("");
    if (e!=null) {
        Console.WriteLine("Combined 2 instance methods, different classes:");
        Console.WriteLine("target...{0}", e.Target == null ? "null" : e.Target);
        foreach(Delegate x in e.GetInvocationList())
            Console.WriteLine("invoke element target: {0}",x.Target);
    }
    Console.WriteLine("");
    if (f!=null) {
        Console.WriteLine("Combined 2 static methods, different classes:");
        Console.WriteLine("target...{0}", f.Target == null ? "null" : f.Target);
        foreach(Delegate x in f.GetInvocationList())
            Console.WriteLine("invoke element target: {0}",x.Target);
    }

    }
}

The output is

Combined 1 static, 1 instance, same class:
target...MyClass
invoke element target:
invoke element target: MyClass
Combined 2 instance methods, different classes:
target...MyClass2
invoke element target: MyClass
invoke element target: MyClass2
Combined 2 static methods, different classes:
target...null
invoke element target:
invoke element target:

Requirements

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0