或者编译器自己推断类型：（n , m）=>
Console.WriteLine(n.ToString())
注：如果有一个方法需要多处调用或者方法里面的代码量较多。还是单独写一个方法较为理想。
最后看一下换成lambda的写法结果显示是否一样
全部代码：
class Program
{
// 定义委托，并引用一个方法，这个方法需要获取一个int型参数返回void
internal delegate void Feedback(int value);
static void Main(string[] args)
{
Program p = new Program();
StaticDelegateDemo();
InstanceDelegateDemo();
ChainDelegateDemo(p);
ChainDelegateDemo2(p);
Console.WriteLine("Hello World!");
string[] names = { "Jeff", "Jee", "aa", "bb" };
//char find = 'e';
//names= Array.FindAll(names, name => name.IndexOf(find) >= 0);
//Array.ForEach(names, Console.WriteLine);
Console.ReadKey();
}
/// <summary>
/// 静态调用
/// </summary>
private static void StaticDelegateDemo()
{
Console.WriteLine("---------委托调用静态方法------------");
Counter(1, 10, null);
//Counter(1, 10, new Feedback(FeedbackToConsole));
//Counter(1, 10, FeedbackToConsole);
Counter(1, 10, value => Console.WriteLine(value));
}
/// <summary>
/// 实例调用
/// </summary>
private static void InstanceDelegateDemo()
{
Console.WriteLine("---------委托调用实例方法------------");
Program p = new Program();
Counter(1, 10, null);
Counter(1, 5, new Feedback(p.InstanceFeedbackToConsole));
}
/// <summary>
/// 委托链调用 1
/// </summary>
/// <param name="p"></param>
private static void ChainDelegateDemo(Program p)
{
Console.WriteLine("---------委托链调用1------------");
Feedback fb1 = new Feedback(FeedbackToConsole);
Feedback fb2 = new Feedback(p.InstanceFeedbackToConsole);
Feedback fbChain = null;
fbChain = (Feedback)Delegate.Combine(fbChain, fb1);
fbChain = (Feedback)Delegate.Combine(fbChain, fb2);
Counter(1, 3, fbChain);
Console.WriteLine();
fbChain = (Feedback)Delegate.Remove(fbChain, new Feedback(FeedbackToConsole));
Counter(1, 3, fbChain);
}
/// <summary>
/// 委托链调用 2
/// </summary>
/// <param name="p"></param>
private static void ChainDelegateDemo2(Program p)
{
Console.WriteLine("---------委托链调用2------------");
Feedback fb1 = new Feedback(FeedbackToConsole);
Feedback fb2 = new Feedback(p.InstanceFeedbackToConsole);
Feedback fbChain = null;
fbChain += fb1;
fbChain += fb2;
Counter(1, 3, fbChain);
Console.WriteLine();
fbChain -= new Feedback(FeedbackToConsole);
Counter(1, 2, fbChain);
}
/// <summary>
/// 使用此方法触发委托回调
/// </summary>
/// <param name="from">开始</param>
/// <param name="to">结束</param>
/// <param name="fb">委托引用</param>
private static void Counter(int from,int to, Feedback fb)
{
for (int val = from; val <= to; val++)
{
// fb不为空，则调用回调方法
if (fb != null)
{
fb(val);
}
//fb?.Invoke(val); 简化版本调用
}
}
/// <summary>
/// 静态回调方法
/// </summary>
/// <param name="value"></param>
private static void FeedbackToConsole(int value)
{
// 依次打印数字
Console.WriteLine("Item=" + value);
}
/// <summary>
/// 实例回调方法
/// </summary>
/// <param name="value"></param>
private void InstanceFeedbackToConsole(int value)
{
Console.WriteLine("Item=" + value);
}
}
