书上的代码,没写全,switch(connectionState2)会一直显示
/使用了没有赋值的局部变量connectionState2/
ConnectionState connectionState;
//...
switch (connectionState)
{
case ConnectionState.Connected:
//...
break;
case ConnectionState.Connecting:
//...
break;
case ConnectionState.Disconnected:
// ...
break;
case ConnectionState.Disconnecting:
//...
break;
}
enum ConnectionState
{
Disconnected,
Connecting,
Connected,
Disconnecting
}
补加一个,两个是一起的是为了显示出使用枚举的话可读性更强,
两者在运行时性能完全一样(改了一下枚举定义的一点问题)。
//比较整数switch和枚举switch
int connectionState;
//...
switch (connectionState)
{
case 0:
//...
break;
case 1:
//...
break;
case 2:
//...
break;
case 3:
//...
break;
}
求使用枚举的switch语句如何调用