Int32.ToString() 太慢了

Question

我有以下职位class：

public struct Pos
{
    public int x;
    public int y;
    public float height;

    public Pos (int _x, int _y, float _height) 
    {
        x = _x;
        y = _y;
        height = _height;
    }

    public override string ToString () 
    {
        return x.ToString() + "," + y.ToString();
    }
}

但是由于我调用了 Pos.ToString() 数千次，这对我来说太慢了。我所需要的只是一种基于 Pos.x 和 Pos.y 获取单个唯一值以用作字典键的有效方法。注意：我不能使用 Pos，因为我只是在 x 和 y.

上比较 Pos 的不同实例

Answer 1

All I need is an efficient way to get a single unique value based on Pos.x and Pos.y, for use as a dictionary key.

不要使用 ToString 作为生成唯一字典键的方法，而是实施 IEquatable<Pos>。这样，您根本不必分配任何字符串来衡量相等性：

public struct Pos : IEquatable<Pos>
{
    public int X { get; private set; }
    public int Y { get; private set; }
    public float Height { get; private set; }

    public Pos(int x, int y, float height)
    {
        X = x;
        Y = y;
        Height = height;
    }

    public bool Equals(Pos other)
    {
        return X == other.X && Y == other.Y;
    }

    public override bool Equals(object obj)
    {
        if (ReferenceEquals(null, obj)) return false;
        return obj is Pos && Equals((Pos) obj);
    }

    public override int GetHashCode()
    {
        unchecked
        {
            return (X*397) ^ Y;
        }
    }

    public static bool operator ==(Pos left, Pos right)
    {
        return left.Equals(right);
    }

    public static bool operator !=(Pos left, Pos right)
    {
        return !left.Equals(right);
    }
}

请注意，如果您使用的是 C#-6，则可以从属性声明中删除 private set。

Int32.ToString() 太慢了

Int32.ToString() too slow

c#

performance

dictionary

hash

tostring