Question

有这个课程：

public static class Command
{
    public const string SET_STB_MEDIA_CTRL = "SET STB MEDIA CTRL ";
    public static string ECHO = "ECHO";
    public static string SET_CHANNEL = "SET CHANNEL ";
    public static string GET_VOLUMN = "GET VOLUMN";
    public static string GET_MAX_VOLUMN = "GET MAX VOLUMN ";
    public string SET_STB_MEDIA_LIST = "SET STB MEDIA LIST ";
}

然后：

public static class MultimediaConstants
{
    public const string VIDEO = "video";
    public const string AUDIO = "audio";
    public const string PHOTO = "photo";
    public const string ALL = "all";
    public const string BACKGROUND_MUSIC = "background_music";
    public const string TV = "tv";
    public const string ACTION_PLAY = "play";
}

重点是，我希望有这样的东西：

public static string SET_STB_MEDIA_CTRL (MultimediaConstants type,  MultimediaConstants action)
{
    return Command.SET_STB_MEDIA_CTRL + "type:" + type + "action:" + action;
}

所以这个方法的结果应该是：

 SET STB MEDIA CTRL type:tv action:play

该方法的调用将是：

 SET_STB_MEDIA_CTRL (MultimediaConstants.TV, MultimediaConstants.ACTION_PLAY);

Answer 1

解决这类问题的方法是让有问题的类具有私有构造函数，并使用该实例的值初始化公共静态字段/属性。这是一种拥有该类型固定有限数量的不可变实例的方法，同时仍然允许方法接受该类型的参数。

以下代码有效C＃6.0。

public class Command
{
    private Command(string value)
    {
        Value = value;
    }

    public string Value { get; private set; }

    public static Command SET_STB_MEDIA_CTRL { get; } = new Command("SET STB MEDIA CTRL ");
    public static Command ECHO { get; } = new Command("ECHO");
    public static Command SET_CHANNEL { get; } = new Command("SET CHANNEL ");
    public static Command GET_VOLUMN { get; } = new Command("GET VOLUMN");
    public static Command GET_MAX_VOLUMN { get; } = new Command("GET MAX VOLUMN ");
    public static Command SET_STB_MEDIA_LIST { get; } = new Command("SET STB MEDIA LIST ");
}

C＃中字符串的枚举

1 个答案: