标签：asi tin version bsp anti ted instant cep ati
C# version 1.0 delegate
// Declare delegate type PerformCalculator public delegate int PerformCalculator(int x, int y); public class SampleClass { private int Add(int x, int y) { return x + y; } private int Minus(int x, int y) { return x - y; } public int DoCalculate(string type, int x, int y) { // Create PerformCalculator instance PerformCalculator add = new PerformCalculator(Add); PerformCalculator minus = new PerformCalculator(Minus); if (type == "add") // Execute delegate return add(x, y); else return minus(x, y); } }
C# version 2.0 introduced anonymous method, creating anonymous methods is essentially a way to pass a code block as a delegate paramater.
// Declare delegate type PerformCalculator public delegate int PerformCalculator(int x, int y); public class Delegate {public int DoCalculate(string type, int x, int y) { // Create PerformCalculator instance PerformCalculator add = delegate(int dx, int dy) { return dx + dy; }; PerformCalculator minus = delegate(int dx, int dy) { return dx - dy; }; if (type == "add") // Execute delegate return add(x, y); else return minus(x, y); } }
C# 3.0 introduced lambda expressions, which are similar in concept to anonymous methods but more expressive and concise.
// Declare delegate type PerformCalculator public delegate int PerformCalculator(int x, int y); public class Delegate { public int DoCalculate(string type, int x, int y) { // Create PerformCalculator instance PerformCalculator add = (dx, dy) => dx + dy; PerformCalculator minus = (dx, dy) => dx - dy; if (type == "add") // Execute delegate return add(x, y); else return minus(x, y); } }
Delegates are the basis for Events.
The delegate must be instantiated with a method or lamda expression that has a compatiable return type and input parameter.
标签：asi tin version bsp anti ted instant cep ati
原文地址：http://www.cnblogs.com/liangzi4000/p/6784114.html
