微信小程序 canvas px转rpx

尺寸自适应

index.wxml

<canvas canvas-id="myCanvas"></canvas>

 

index.js

全局变量

var app = getApp();
var device = wx.getSystemInfoSync();
var width = device.windowWidth;//设备屏幕宽度
var xs = width / canvas宽度;

aaa:function(){

　　var context = wx.createCanvasContext('myCanvas');
　　context.fillText('内容', 100 * xs , 100 * xs)

}