TypeScript 扩展声明文件 .d.ts

如：扩展LayaAir的Vector3，加入一个say方法
LayaAirExtensions.d.ts

declare module Laya{
      interface Vector3 {
            say(msg:string):void;
      }
}
//或
/*declare module laya.d3.math{
      interface Vector3{
            say(msg:string):void;
      }
}*/

let v3=new Laya.Vector3();
v3.say("hello");//不报错