Lambda 表达式中的变量范围

delegate bool D();

delegate bool D2(int i);

class Test

{

    D del;

    D2 del2;

    public void TestMethod(int input)

    {

        int j = ;

        // Initialize the delegates with lambda expressions.

        // Note access to 2 outer variables.

        // del will be invoked within this method.

        del = () => { j = ;  return j > input; };

        // del2 will be invoked after TestMethod goes out of scope.

        del2 = (x) => {return x == j; };

        // Demonstrate value of j:

        // Output: j = 0

        // The delegate has not been invoked yet.

        Console.WriteLine("j = {0}", j);        // Invoke the delegate.

        bool boolResult = del();

        // Output: j = 10 b = True

        Console.WriteLine("j = {0}. b = {1}", j, boolResult);

    }

    static void Main()

    {

        Test test = new Test();

        test.TestMethod();

        // Prove that del2 still has a copy of

        // local variable j from TestMethod.

        bool result = test.del2();

        // Output: True

        Console.WriteLine(result);

        Console.ReadKey();

    }

}