端口在飞镖的js地图

Question

我怎样才能在dart中传递这个常量？

const CHANNEL_STATES = { 
    closed: "closed", 
    errored: "errored", 
    joined: "joined", 
    joining: "joining", 
    leaving: "leaving", 
} 

我需要它来调用前。 CHANNEL_STATES.closed 感谢

Answer 1

你可以做到这一点与类和常量静态成员：

class CHANNEL_STATES { 
    static const String closed = "closed"; 
    static const String errored = "errored"; 
    static const String joined = "joined"; 
    static const String joining = "joining"; 
    static const String leaving = "leaving"; 
} 

Answer 2

我不知道你问的什么，但在DART类似的地图常数是：

const channelStates = const { 
    "closed": "closed", 
    "errored": "errored", 
    "joined": "joined", 
    "joining": "joining", 
    "leaving": "leaving", 
}; 

镖地图文字可以使用任何对象作为重点，所以使用字符串作为密钥，您需要引用它。你不能像JavaScript中那样使用一个没有引号的标识符。