internal static void ForeachDoaction(this MyBitFlag e, System.Action <MyBitFlag> action)
{
if (action == null)
{
System.Console.WriteLine("Fail. Action is null.");
return;
}
//取决于基础类型, int循环32次, 他共有32bits
for (uint i = 1; i != 0; i <<= 1)
{
uint m = (uint)e & i; //如果这一位为open
if (m != 0)
{
action((MyBitFlag)m);
}
}
}
//向Enum添加方法
internal static MyBitFlag Clear(this MyBitFlag e, MyBitFlag flag)
{
return(e & (~flag));
}
static void Main15(string[] args)
{
Console.WriteLine(Enum.GetUnderlyingType(typeof(MyEnum)));
#region Enum <-> number / Enum -> string
//MyEnum的实例其实就是一个byte
MyEnum me = (MyEnum)23;
//查看一个enum实例的方法
Console.WriteLine(me.ToString()); //Enum重写了Object.Tostring, 虽然enum实例是个数字, 但返回的是对应的变量名A
Console.WriteLine(me.ToString("D")); //查看常量值的十进制
Console.WriteLine(me.ToString("X")); //查看常量值的十六进制
Console.WriteLine(Enum.Format(typeof(MyEnum), (Byte)23, "G")); //静态方法, 不通过实例
Console.WriteLine("\r\nDisplay the values, 因为ToString被重写, 打印出来的是常量数值的符号名");
Array arr = Enum.GetValues(typeof(MyEnum)); //Array是个抽象基类, GetValue返回子类, MyEnum[]
foreach (var b in arr)
{
Console.WriteLine(b);
}
Console.WriteLine("\r\nDisplay the names");
string[] names = Enum.GetNames(typeof(MyEnum));
foreach (string s in names)
{
Console.WriteLine(s);
}
#endregion
#region string -> enum
Console.WriteLine("\r\n\r\n");
//Parse方法, 本质是string->object
MyEnum e = (MyEnum)Enum.Parse(typeof(MyEnum), "A");
Console.WriteLine(e.ToString("D"));
//检查是否有定义
if (Enum.IsDefined(typeof(MyEnum), "s"))
{
Console.WriteLine("Name is defined");
}
else
{
Console.WriteLine("Name is not defined");
}
#endregion
#region Bit Flag
//展示内置bit flag的一个有关文件操作的内容
//获得.exe的位置
string path = System.Reflection.Assembly.GetEntryAssembly().Location;
Console.WriteLine(path);
System.IO.FileAttributes fa = System.IO.File.GetAttributes(path);
Console.WriteLine("Is the file read only?");
Console.WriteLine(fa);
Console.WriteLine((fa & System.IO.FileAttributes.ReadOnly) != 0);
//Bit flag的特点是查找时要考虑几个选项组合的结果
//bit flag -> string
Console.WriteLine("\r\n" + (MyBitFlag)3); //3 -> 1|2 -> ToString -> Layer1,Layer2
Console.WriteLine(((MyBitFlag)0x3F).ToString("F")); //"F"格式和[Flags]类似
//string -> bit flag
MyBitFlag mb = (MyBitFlag)Enum.Parse(typeof(MyBitFlag), "Layer1 , Layer2 "); //内部空格会被切掉
Console.WriteLine(mb.ToString("D"));
//Parse有报错可能 - 无法找到时
#endregion
#region 通过extention method向enum中添加方法
MyBitFlag m = MyBitFlag.Layer6 | MyBitFlag.Layer3;
m.ForeachDoaction((MyBitFlag mf) => { Console.WriteLine("Foreach Print: " + mf.ToString()); });
#endregion
}
