使用常量文字初始化 ArrayList

Question

下面的ArrayList是否可以直接初始化而不需要aFileExt字符串数组？

private static string[] aFileExt = 
     {"css", "gif", "htm", "html", "txt", "xml" };
private System.Collections.ArrayList alFileTypes =
     new System.Collections.ArrayList(aFileExt);

下面的行是目标，但我的 .Net 编译器不喜欢它：

private static System.Collections.ArrayList alFileTypes = 
     new System.Collections.ArrayList({"css","gif","htm","html","txt","xml"});

我正在使用 .net 微框架，因此无法访问泛型类型。

Answer 1

C# 1 或 2：

private static ArrayList alFileTypes = 
     new ArrayList(new string[] {"css","gif","htm","html","txt","xml"});

C# 3 使用隐式类型数组：

private static ArrayList alFileTypes = 
    new ArrayList(new[] {"css","gif","htm","html","txt","xml"});

C# 3 使用集合初始值设定项：

private static ArrayList alFileTypes = 
    new ArrayList{"css","gif","htm","html","txt","xml"};

或者创建您自己的辅助方法：

public static ArrayList CreateList(params object[] items)
{
    return new ArrayList(items);
}

那么：

static ArrayList alFileTypes = CreateList("css","gif","htm","html","txt","xml");

顺便说一句，您不使用通用集合的任何原因？

Answer 2

如果您使用的是 .NET 2.0 或更高版本，则应该使用通用 List 类型（即使它是 List

如果您使用的是 .NET 3.5 或更高版本，则可以使用以下语法：

private static List<string> fileTypes = new List<string>()
{ 
    "css","gif","htm","html","txt","xml" 
};

但是，无论哪种方式，如果您想坚持使用 ArrayList，您都可以执行以下操作：

private static System.Collections.ArrayList alFileTypes = 
 new System.Collections.ArrayList(new object[] {"css","gif","htm","html","txt","xml"});

Answer 3

使用通用 List 而不是 ArrayList 的 C# 3.0：

private static List<string> alFileTypes =
    new List<string> {"css","gif","htm","html","txt","xml"};

Answer 4

private static System.Collections.ArrayList alFileTypes = 
 new System.Collections.ArrayList(new string [] {"css","gif","htm","html","txt","xml"});

Answer 5

尝试

private static System.Collections.ArrayList alFileTypes =   new System.Collections.ArrayList(){"css","gif","htm","html","txt","xml"};

Answer 6

是的，只需更改

private static System.Collections.ArrayList alFileTypes = 
     new System.Collections.ArrayList({"css","gif","htm","html","txt","xml"});

为

private static System.Collections.ArrayList alFileTypes = 
     new System.Collections.ArrayList(new string[] {"css","gif","htm","html","txt","xml"});