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Expression.Call Method (Expression, MethodInfo, Expression, Expression)

Creates a MethodCallExpression that represents a call to a method that takes two arguments.

Namespace:  System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

public static MethodCallExpression Call(
	Expression instance,
	MethodInfo method,
	Expression arg0,
	Expression arg1
)

Parameters

instance
Type: System.Linq.Expressions.Expression

An Expression that specifies the instance for an instance call. (pass null for a static (Shared in Visual Basic) method).

method
Type: System.Reflection.MethodInfo

The MethodInfo that represents the target method.

arg0
Type: System.Linq.Expressions.Expression

The Expression that represents the first argument.

arg1
Type: System.Linq.Expressions.Expression

The Expression that represents the second argument.

Return Value

Type: System.Linq.Expressions.MethodCallExpression
A MethodCallExpression that has the NodeType property equal to Call and the Object and Method properties set to the specified values.

The following code example shows how to create an expression that calls an instance method that has two arguments.

// Add the following directive to your file: 
// using System.Linq.Expressions;   
public class SampleClass
{
    public int AddIntegers(int arg1, int arg2)
    {
        return arg1 + arg2;
    }
}

static public void TestCall()
{
    // This expression represents a call to an instance method that has two arguments. 
    // The first argument is an expression that creates a new object of the specified type.
    Expression callExpr = Expression.Call(
        Expression.New(typeof(SampleClass)),
        typeof(SampleClass).GetMethod("AddIntegers", new Type[] { typeof(int), typeof(int) }),
        Expression.Constant(1),
        Expression.Constant(2)
        );

    // Print out the expression.
    Console.WriteLine(callExpr.ToString());

    // The following statement first creates an expression tree, 
    // then compiles it, and then executes it.
    Console.WriteLine(Expression.Lambda<Func<int>>(callExpr).Compile()());

    // This code example produces the following output: 
    // 
    // new SampleClass().AddIntegers(1, 2) 
    // 3
}

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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