List<T> 比较的问题，

Question

自定义的一个类
public class PixelColor    {
        Point point;
        Color color;        public  PixelColor(Point Point,Color Color)
        {
            this.point = Point;
            this.color = Color;
        }
    ｝
    
   需要定义一个此对象的集合类：public class PixelColorCollection : List<PixelColor> ｛｝   new多个PixelColor类的对象 添加到 两个List<T>里面。   然后比较这两个List<T> 是否相等。 
判断相等的条件：1，两个List<T> 内的PixelColor对象个数相等 2，List<T> 内每个PixelColor对象的point 和color的数值相等3. List<T> 内PixelColor对象的顺序可以不一样。4.我认为代码应该具有如下样式：
public class PixelColorCollection : List<PixelColor>
    {
                public override bool Equals(object obj)
        {        ｝
        
     ｝也不知道对不对，请各位朋友不吝赐教

Answer 1

对，对于自定义类的比较，重载Equals

Answer 2

        public override bool Equals(object obj)
        {
            PixelColorCollection  anotherObj = (PixelColorCollection )obj;
            return this.point.Equals(anotherObj.point);
        }

Answer 3

public class PixelColorCollection: List<PixelColor> {
public static Boolean operator ==(PixelColorCollection dFirst, PixelColorCollection dSecond) {
if (dFirst.Count != dSecond.Count) return false;
foreach (String aKey in dFirst.Keys) {
if (dSecond.ContainsKey(aKey) == false) return false;
if (dFirst[aKey] != dSecond[aKey]) return false;
}
return true;
} public static Boolean operator !=(PixelColorCollection dFirst, PixelColorCollection dSecond) {
return !(dFirst == dSecond);
}
}

Answer 4

public class PixelColor
{
    public Point Point { get; set; }
    public Color Color { get; set; }    public PixelColor(Point point, Color color)
    {
        this.Point = point;
        this.Color = color;
    }
}public class PixelColorCollection : List<PixelColor>
{
    public static bool Compare(PixelColorCollection c1, PixelColorCollection c2)
    {
        if (c1 == c2) return true;        if (c1 == null || c2 == null || c1.Count != c2.Count) return false;        var s1 = string.Join(",", c1
            .Select(item => item.Point.ToString() + item.Color.ToString())
            .OrderBy(element => element).ToArray());        var s2 = string.Join(",", c2
            .Select(item => item.Point.ToString() + item.Color.ToString())
            .OrderBy(element => element).ToArray());        return s1 == s2;
    }
}
PixelColorCollection c1 = new PixelColorCollection();
PixelColorCollection c2 = new PixelColorCollection();
PixelColorCollection c3 = new PixelColorCollection();
PixelColorCollection c4 = new PixelColorCollection();
PixelColorCollection c5 = new PixelColorCollection();c1.AddRange(new PixelColor[] {
        new PixelColor(new Point(0,0), Colors.Red),
        new PixelColor(new Point(0,0), Colors.Yellow),
        new PixelColor(new Point(0,0), Colors.Blue)
    });c2.AddRange(new PixelColor[] {
        new PixelColor(new Point(0,0), Colors.Yellow),
        new PixelColor(new Point(0,0), Colors.Blue),
        new PixelColor(new Point(0,0), Colors.Red)
    });c3.AddRange(new PixelColor[] {
        new PixelColor(new Point(0,0), Colors.Yellow),
        new PixelColor(new Point(0,0), Colors.Blue)
    });c4.AddRange(new PixelColor[] {
        new PixelColor(new Point(0,0), Colors.Yellow),
        new PixelColor(new Point(0,0), Colors.Blue),
        new PixelColor(new Point(0,0), Colors.Red),
        new PixelColor(new Point(0,0), Colors.Green)
    });c5.AddRange(new PixelColor[] {
        new PixelColor(new Point(0,0), Colors.Yellow),
        new PixelColor(new Point(0,0), Colors.Blue),
        new PixelColor(new Point(0,1), Colors.Red)
    });Console.WriteLine(c1 == c2);
Console.WriteLine(c1 == c3);
Console.WriteLine(c1 == c4);
Console.WriteLine(c1 == c5);
Console.WriteLine("-----------------");
Console.WriteLine(PixelColorCollection.Compare(c1, c2));
Console.WriteLine(PixelColorCollection.Compare(c1, c3));
Console.WriteLine(PixelColorCollection.Compare(c1, c4));
Console.WriteLine(PixelColorCollection.Compare(c1, c5));至于利用 hash 及重载操作符的方法可以参考http://blog.csdn.net/alex197963/archive/2007/04/22/1574893.aspx