[英]Return a collection of objects from a bitmask
I "need" a better way to generate a collection of objects from a bitmask (a ushort passed, on binary form it's interpreted as a mask) 我“需要”一种更好的方法来从位掩码生成一个对象集合(一个ushort传递,在二进制形式上它被解释为一个掩码)
The easy, non elegant solution would be: 简单,非优雅的解决方案是:
public static Things[] Decode(ushort mask) { switch (mask) { case 1: // 1 return new[] { new Thing(0) }; case 2: //10 return new[] { new Thing(1) }; case 3: // 11 return new[] { new Thing(1), new Thing(0) }; case 4: // 100 return new[] { new Thing(2) }; case 5: // 101 return new[] { new Thing(2), new Thing(0) };
// so on ......
public static Things[] Decode(ushort mask) { switch (mask) { case 1: // 1 return new[] { new Thing(0) }; case 2: //10 return new[] { new Thing(1) }; case 3: // 11 return new[] { new Thing(1), new Thing(0) }; case 4: // 100 return new[] { new Thing(2) }; case 5: // 101 return new[] { new Thing(2), new Thing(0) };
// so on ......
Try the following 请尝试以下方法
public static List<Thing> Decode(ushort mask) {
var list = new List<Thing>();
for ( var index = 0; index < 16; index++ ) {
var bit = 1 << index;
if ( 0 != (bit & mask) ) {
list.Add(new Thing(index));
}
}
return list;
}
untested, uses fewer iterations than other solutions ;-) 未经测试,使用比其他解决方案更少的迭代;-)
List<Thing> things = new List<Thing>();
for (int n=0;n<4;n++)
{
int val = Math.Pow(2,i);
if ((mask & val) == val)
{
things.Add(new Thing(val));
}
}
return things.ToArray();
It could look like you want an Enum with the [Flags] attribute. 看起来你想要一个带有[Flags]属性的Enum。 You would have:
你将会拥有:
[Flags]
enum ThingType
{
THING1 = 1,
THING2 = 2,
THING2 = 4,
THING3 = 8,
THING4 = 16
}
This lets you do things like 这可以让你做的事情
ThingType x = ThingType.THING1 | ThingType.THING3;
And also 并且
int x = 3;
ThingType y = (ThingType)x; // THING1 | THING2
List<Thing> Things = new List<Thing>();
ushort msk = mask;
for (int 0 = 0; i < 16; ++i)
{
if ((msk & 1) != 0)
{
Things.Add(new Thing(i));
}
msk >>= 1;
}
return Things.ToArray();
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