比較數組列表中的對象

Question

我有一個包含對象及其屬性的數組列表。有沒有辦法比較對象的屬性？

更新下面列表例如

listTA = {(ID, MonAry[], RequestDate), (ID, MonAry[], RequestDate)}; 

Answer 1

創建一個新的類中實現IComparer接口。那麼你可以通過調用myList.Sort(new MyComparer());排序列表，你可以使用新的MyComparer().Compare(firstOne, secondOne);

樣品每一個比較與其他一個：

using System; 
using System.Collections; 

public class SamplesArrayList { 

    public class myReverserClass : IComparer { 

     // Calls CaseInsensitiveComparer.Compare with the parameters reversed. 
     int IComparer.Compare(Object x, Object y) { 
      // you can implement this method as you wish! cast your x and y objects and access to their properties. 
      return((new CaseInsensitiveComparer()).Compare(y, x)); 
     } 

    } 

    public static void Main() { 

     // Creates and initializes a new ArrayList. 
     ArrayList myAL = new ArrayList(); 
     myAL.Add("The"); 
     myAL.Add("quick"); 
     myAL.Add("brown"); 
     myAL.Add("fox"); 
     myAL.Add("jumps"); 
     myAL.Add("over"); 
     myAL.Add("the"); 
     myAL.Add("lazy"); 
     myAL.Add("dog"); 

     // Displays the values of the ArrayList. 
     Console.WriteLine("The ArrayList initially contains the following values:"); 
     PrintIndexAndValues(myAL); 

     // Sorts the values of the ArrayList using the default comparer. 
     myAL.Sort(); 
     Console.WriteLine("After sorting with the default comparer:"); 
     PrintIndexAndValues(myAL); 

     // Sorts the values of the ArrayList using the reverse case-insensitive comparer. 
     IComparer myComparer = new myReverserClass(); 
     myAL.Sort(myComparer); 
     Console.WriteLine("After sorting with the reverse case-insensitive comparer:"); 
     PrintIndexAndValues(myAL); 

    } 

    public static void PrintIndexAndValues(IEnumerable myList) { 
     int i = 0; 
     foreach (Object obj in myList) 
     Console.WriteLine("\t[{0}]:\t{1}", i++, obj); 
     Console.WriteLine(); 
    } 

} 

另一IComparer的樣本：

private class sortYearAscendingHelper : IComparer 
{ 
    int IComparer.Compare(object a, object b) 
    { 
     car c1=(car)a; 
     car c2=(car)b; 
     if (c1.year > c2.year) 
     return 1; 
     if (c1.year < c2.year) 
     return -1; 
     else 
     return 0; 
    } 
} 

Answer 2

檢查SO後，

Arraylist can't compare objects after they are loaded from disk

檢查教程的博客或者使用IComparable或IComparer2

http://www.codeproject.com/KB/recipes/Beginners_Sort.aspx#IComparablevsIComparer2

感謝