[C#.NET][VB.NET] 實作 IEqualityComparer 不分大小寫
實作IEqualityComparer,不分大小寫比較
//實作
public class InComparer : IEqualityComparer
{
CaseInsensitiveComparer myComparer = new CaseInsensitiveComparer();
public int GetHashCode(object obj)
{
return obj.ToString().ToLowerInvariant().GetHashCode();
}
public new bool Equals(object x, object y)
{
if (myComparer.Compare(x, y) == 0)
{
return true;
}
else
{
return false;
}
}
}
因為不分大小寫所以First與first視為相同,程式在執行時會出現例外。
//引用類別
Hashtable myData = new Hashtable(new InComparer());
myData.Add("First", "1st");
myData.Add("Senond", "2nd");
myData.Add("Third", "3rd");
myData.Add("Fourth", "4th");
myData.Add("Fifth", "5th");
myData.Add("first", "1st");
foreach (DictionaryEntry myEntry in myData)
{
Console.WriteLine("{0} = {1}", myEntry.Key, myEntry.Value);
}
當然也可以用CollectionsUtil類別來不分大小寫,這段程式看起來就短多了。
Hashtable myColl = CollectionsUtil.CreateCaseInsensitiveHashtable();
myColl.Add("A", "1234");
myColl.Add("a", "1234");
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