纯canvas页面自适应方法

var scale = 1 / window.devicePixelRatio;
document.querySelector('meta[name="viewport"]').setAttribute('content','width=device-width,initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' + scale + ', user-scalable=no');
function stageBreakHandler(event)
{
    if(stageWidth!=document.documentElement.clientWidth||stageHeight!= document.documentElement.clientHeight)
    {
        stageWidth =  document.documentElement.clientWidth;
        stageHeight = document.documentElement.clientHeight;
        //外部元素自适应
        canvas.width = stageWidth ;
        canvas.height = stageHeight;
 
        //内部元素自适应
        stageScale = stageWidth/750;//宽度自适应；
//    stageScale = stageHeight/1206;//高度自适应两者选一
        container.scaleX = stageScale;
        container.scaleY = stageScale;
//    bitmap.x = (stageWidth -  750*bitmap.scaleX)/2;//高度自适应时解开这个注释 保证图片居中
        if(leftBtn)
        {
            leftBtn.x = stageWidth - 100;
        }
    }
    stage.update();
}

注意：上面代码的750和1206是素材的大小不是屏幕的大小，也就是你自适应的素材有多大就写多大