<!--canvas.wxml-->

<view class="container">

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

</view>

/**canvas.wxss*/

.myCanvas{

    border: 1px solid #ccc;

    width:100%;

    height:250px;

}

<canvas canvas-id="myCanvas" clas

s="myCanvas" ></canvas>

const ctx = wx.createCanvasContext('myCanvas')

ctx.setFillStyle('red')

ctx.fillRect(10, 10, 150, 75)

ctx.draw()

//canvas.js

//获取应用实例 

var app = getApp() 

Page({

    onLoad: function() {

        const ctx = wx.createCanvasContext('myCanvas');

        ctx.setFillStyle('red');

        ctx.fillRect(10, 10, 150, 75);

        ctx.draw();

    }

})