使用常量文字初始化ArrayList

Question

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

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 Micro Framework,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使用集合初始化程序:

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

或者创建自己的帮助方法:

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

然后:

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

您没有使用通用集合的原因,顺便说一下？

Answer 2

如果你使用的是.NET 2.0或更高版本,你应该使用泛型List<T>类型(即使它是List<object>,它会给你相同的功能ArrayList).

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" 
};

无论哪种方式,如果你想坚持下去ArrayList,你可以这样做:

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

Answer 3

C#3.0带有泛型List<T>,而不是ArrayList:

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