Laya.stage.on(Event.MOUSE_DOWN, this, this.onMouseDown);
onMouseDown(e) {
const Event = Laya.Event;
// 手机上才有 touches 属性
let touches = e.touches;
if (touches && touches.length == 2) {
preRadian = Math.atan2(
touches[0].stageY - touches[1].stageY,
touches[0].stageX - touches[1].stageX);
Laya.stage.on(Event.MOUSE_MOVE, this, this.onMouseMove);
}
}