C# | Type.IsAssignableFrom(Type) Method

Type.IsAssignableFrom(Type) Method is used determine whether an instance of a specified type can be assigned to a variable of the current type.

Syntax: public virtual bool IsAssignableFrom (Type c); Here, it takes the type to compare with the current type. 

Return Value: This method returns true if any of the following conditions is true:

• c and the current instance represent the same type.
• c is derived either directly or indirectly from the current instance. c is derived directly from the current instance if it inherits from the current instance; c is derived indirectly from the current instance if it inherits from a succession of one or more classes that inherit from the current instance.
• The current instance is an interface that c implements.
• c is a generic type parameter, and the current instance represents one of the constraints of c.

Below programs illustrate the use of Type.IsAssignableFrom() Method: 

Example 1:

csharp

// C# program to demonstrate the
// Type.IsAssignableFrom() Method
using System;
using System.Globalization;
using System.Reflection;
using System.IO;

// Defining MyClass extended
// from TypeDelegator
public class MyClass : TypeDelegator { }

class GFG {

    // Main Method
    public static void Main()
    {
        // Declaring and initializing object of Type
        Type objType = typeof(TypeDelegator);

        // Getting array of Properties by
        // using IsAssignableFrom() Method
        bool status = objType.IsAssignableFrom(typeof(MyClass));

        // Display the Result
        if (status)
            Console.WriteLine("Instance of a specified type can be "
                   + "assigned to a variable of the current type.");
        else
            Console.WriteLine("Instance of a specified type can't be "
                     + "assigned to a variable of the current type.");
    }
}

Output:

Instance of a specified type can be assigned to a variable of the current type.

Example 2:

csharp

// C# program to demonstrate the
// Type.IsAssignableFrom() Method
using System;
using System.Globalization;
using System.Reflection;
using System.IO;

class GFG {

    // Main Method
    public static void Main()
    {
        // Declaring and initializing object of Type
        Type objType = typeof(double);

        // Getting array of Properties by
        // using IsAssignableFrom() Method
        bool status = objType.IsAssignableFrom(typeof(int));

        // Display the Result
        if (status)
            Console.WriteLine("Instance of a specified type can be "
                   + "assigned to a variable of the current type.");
        else
            Console.WriteLine("Instance of a specified type can't be "
                     + "assigned to a variable of the current type.");
    }
}

Output:

Instance of a specified type can't be assigned to a variable of the current type.

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.type.isassignablefrom?view=netframework-4.8