setFrameSize在chrome生效，小游戏平台没生效

Creator 2.x
#1 
    let screen=cc.view.getFrameSize()
    console.log("screen1",screen.width,screen.height)
    cc.view.setFrameSize(screen.width*0.5,screen.height*0.5)
    screen=cc.view.getFrameSize()
    console.log("screen2",screen.width,screen.height)

使用如上代码，chrome中打印了变化，但是小游戏平台没有改变。