本來想利用裝試者來監聽數據更改. 代碼如下:export function fireBind(type:string) {        return function (taget:any, key:string, descriptor:TypedPropertyDescriptor<any>)            {            let oldSet = descriptor.set;             descriptor.set = function(val){                 MessageCenter.fire(new ModelEvent(type, val));                console.log('1111');                 oldSet.call(null, val);                console.log('2222');             }         }     }class Test {    private _selected;    @fireBind(EventState.GOODS_SELECTED)    public set selected(data:any) {        this._selectedData = data;        console.log('this._selectedData:', this._selectedData);     }    public get selected(){         return this._selectedData;   } }調用 :const T = new Test(); T.selected = 'test';console.log(T.selected);輸出結果:1111this._selectedData: testnull;