22.2 Delegate instantiation

最新推荐文章于 2016-11-22 15:27:00 发布

最新推荐文章于 2016-11-22 15:27:00 发布 · 74 阅读

本文详细介绍了如何通过委托创建表达式来创建委托实例。这些实例可以引用静态方法、目标对象及其实例方法，或是另一个委托。一旦创建，委托实例将始终引用相同的目标对象和方法。

An instance of a delegate is created by a delegate-creation-expression (§14.
5.10.3). The newly created delegate
instance then refers to either:
? The static method referenced in the delegate-creation-expression, or
? The target object (which cannot be null) and instance method referenced in
the delegate-creationexpression,
or
? Another delegate
[Example: For example:
delegate void D(int x);
class Test
{
public static void M1(int i) {?}
public void M2(int i) {?}
}
class Demo
{
static void Main() {
D cd1 = new D(Test.M1); // static method
Test t = new Test();
D cd2 = new D(t.M2); // instance method
D cd3 = new D(cd2); // another delegate
}
}
end example]
Once instantiated, delegate instances always refer to the same target
object and method. [Note: Remember, when
two delegates are combined, or one is removed from another, a new delegate
results with its own invocation list;
the invocation lists of the delegates combined or removed remain unchanged.
end note]