TypeScript 编译错误无法调用类型缺少调用签名的表达式

TypeScript Compile Error Cannot invoke an expression whose type lacks a call signature

下面的代码通过 gulp 转译得到了我这个错误:

[tsc] > C:/Workarea/MyFirstAngular/src/enum/msg.ts(35,33): error TS2349: Cannot invoke an expression whose type lacks a call signature. Failed to compile TypeScript: Error: tsc command has exited with code:2

module MessageUtil {
    enum Morning {
    "Good Morning",
    "Great to see you!",
    "Good day.",
    "Lovely day today, isn't it?",
    "What's up?",
    "Nice to meet you",
}
}
    export class MessageData {
        private getRandomElementOfEnum(e : any):string{
            var length:number = Object.keys(e).length();  //<-- This is Line 35
            return e[Math.floor((Math.random() * length)+1)];
        }
        public getRandMorning():string {
            return this.getRandomElementOfEnum(Morning);
        }
    }
}

有人知道我到底错在哪里吗?

我的设置: -想法 14 -Node.js -Gulp -gulp-tsc -gulp-连接(用于 Livereload)

有同样错误信息的人 --> 检查你的代码语法

发现我的错。这是不是Java。

 private getRandomElementOfEnum(e : any):string{
      var length:number = Object.keys(e).length();  //<-- This is Line 35
      return e[Math.floor((Math.random() * length)+1)];
 }

应该是:

    private getRandomElementOfEnum(e : any):string{
        var length:number = Object.keys(e).length;  // <--- WITHOUT ()
        return e[Math.floor((Math.random() * length)+1)];
    }