10 2013 档案

摘要：Clever response Dave, but insufficient. I'll admit I've suggested this myself for certain questions but I think more is needed here. The OP may run one query where count(*) and count(1) return the same result and have the same performance, but that doesn't mean they always will. Similarl 阅读全文

摘要：1.定义的委托和方法 delegate void TestDelegate(string s); static void M(string s) { Console.WriteLine(s); }2.常规委托:// Original delegate syntax required // initialization with a named method. TestDelegate testdelA = new TestDelegate(M);3.匿名方法 // C# 2.0: A delegate can be initi... 阅读全文

摘要：事件功能：当某个动作发生时，能够回调一些方法来达到执行一系列操作的功能。原理：委托是方法的接口，定义了方法的规范，包括参数和返回值，这样也是为了安全的回调，而事件是委托的实力，一个事件被定义后可以被多次实例化（+=），这就依赖一个叫委托链的概念，通过调用委托可顺次调用一些列的方法。道理讲明白了，不在罗搜，开始上代码。1.定义委托public delegate void PropertyChangedEventHandler(object sender, PropertyChangedEventArgs e);2.定义事件public event PropertyChangedEventHand 阅读全文