interface ICompressible
{
void Compress();
void Decompress();
}
interface ILoggedCompressible
: ICompressible
{
void LogSavedBytes();
}
public class Document : ILoggedCompressible
{
// 实现ICompressible
public void Compress(){ …}
public void Decompress() { …}
// 实现ILoggedCompressible
public void LogSavedBytes() { …}
// 要实现所有的接口成员
as operator
foreach (Document doc in folder) { IStorable isDoc = doc as IStorable; if (isDoc != null) { isDoc.Read(); }else{ Console.WriteLine("IStorable not supported");doc.Encrypt(); } … } as 有左右两个操作数 Casts the left operand to the type specified by the right operand. Returns null if the cast fails.
原文：http://www.cnblogs.com/GSONG/p/4399062.html