.net FrameWork 框架博大精深，用着忘着，计划对自己能够想到知识点梳理一下，此篇是对自定义排序的理解：
class Program {
static void Main(string[] args)
{
Random random = new Random();
ClassA[] arr = new ClassA[];//数组还有IEnumerator是没有实现Sort的，List实现了
Console.WriteLine("Source Value:");
for (int i = ; i < ; i++)
{
arr[i] = new ClassA(random.Next(), random.Next());
Console.WriteLine(arr[i].XY);
}
Console.WriteLine();
Console.WriteLine("Source ToList Value:");
var list = arr.ToList();
for (int i = ; i < ; i++)
{
Console.WriteLine(list[i].XY);
}
Console.WriteLine();
Console.WriteLine("Source ToList Sort Value:");
list.Sort();
for (int i = ; i < ; i++)
{
Console.WriteLine(list[i].XY);
}
Console.WriteLine();
Console.WriteLine("Source ToList Compare Value:");
list.Sort(new ClassAComparer());//简单实现降序
//等同于 list.Sort((x,y)=>-x.CompareTo(y));//实现降序
for (int i = ; i < ; i++)
{
Console.WriteLine(list[i].XY);
}
Console.WriteLine();
Console.WriteLine("Priority Source Value:");
//在一些常用场景经常会有优先级的概念，针对有优先级的排序，可以参照如下：
//Tuple<int,int> ，Item1的优先级大于Item2的优先级
List<Tuple<int, int>> list_priority = new List<Tuple<int, int>>();
for (int i = ; i < ; i++)
{
Tuple<int, int> xy = new Tuple<int, int>(random.Next(), random.Next());
list_priority.Add(xy);
Console.WriteLine(string.Format("{{X:{0},Y:{1}}}", xy.Item1, xy.Item2));
}
Console.WriteLine();
Console.WriteLine("Priority Source Sort Value:");
list_priority.Sort((x, y) =>
{
if (x.Item1 > y.Item1)
return ;
else if (x.Item1 == y.Item1)
return x.Item2 - y.Item2;
else
return -;
});
for (int i = ; i < ; i++)
{
Console.WriteLine(string.Format("{{X:{0},Y:{1}}}", list_priority[i].Item1, list_priority[i].Item2));
}
Console.ReadKey();
//其实还有一些场景，会用到权重的概念，尤其是针对一些客户定级别时候，这个时候的排序，建议权重高的，
//排序时候去平方，或者倍乘等方式，涉及到权重的，都是玄之又玄，出来的结果大致满意就很棒了。。。
}
}
class ClassA:IComparable<ClassA>//定义在对象上的自定义排序，这里引用泛型，不需类型转换
{
public ClassA(int x, int y)
{
this.X = x;
this.Y = y;
}
public int X { get; set; }
public int Y { get; set; }
public string XY
{
get
{
return string.Format("{{X:{0},Y:{1}}}", X, Y);//C#打印大括号，左大括号{{，有大括号}}
}
}
public int CompareTo(ClassA other)
{
int val = X + Y;
int otherVal = other.X + other.Y;
return val - otherVal;//三种结果 1,-1,0分别是大，小，相等
}
}
class ClassAComparer : IComparer<ClassA>//单独定义的排序规则
{
public int Compare(ClassA x, ClassA y)
{
int valX = x.X + x.Y;
int valY = y.X + y.Y;
return valY - valX;
}
}在做一个对象集的比较时候，用到不同的比较规则，这个时候，用一个封装，如下：
public class Compare<T> : IEqualityComparer<T>
{
private Func<T,T,bool> _equalsComparer; public Compare(Func<T,T,bool> equalsComparer)
{
this._equalsComparer = equalsComparer;
} public bool Equals(T x, T y)
{
if (null != this._equalsComparer)
return this._equalsComparer(x, y);
else
return false;
} public int GetHashCode(T obj)
{
return obj.GetHashCode();
}
}