微信小程序 怎样获取屏幕宽度 赋值到canvas 宽度上

Question

  onReady: function () {
    // 页面渲染完成 
    var cxt_arc = wx.createCanvasContext('canvas1');//创建并返回绘图上下文context对象。 
    cxt_arc.setLineWidth(6);
    cxt_arc.setStrokeStyle('#80868a');
    cxt_arc.setLineCap('round')
    cxt_arc.beginPath();//开始一个新的路径 
    cxt_arc.arc(125, 125, 120, Math.PI * 0.8, 2.2 * Math.PI, false);//设置一个原点(125,125)，半径为120的圆的路径到当前路径 
    cxt_arc.stroke()//对当前路径进行描边 
    cxt_arc.draw();

  },

Answer 1

wx.getSystemInfo({
success: function(res) {

console.log(res.windowHeight)  

}
})