微信小程序画布使用范例详解

来源：互联网发布：淘宝网歌莉娅秋装编辑：程序博客网时间：2024/05/13 06:58

今天关于微信小程序的画布，做了个简单的范例，大家来看看吧
wxml的代码

<canvas style="width: 300px; height: 200px;" canvas-id="fourCanvas" bindtouchstart="start" bindtap="click" >画布效果</canvas>

js代码

Page({   data:{     canvaid:'fourCanvas',     num:'1'   },  canvasIdErrorCallback: function (e) {    console.error(e.detail.errMsg)  },  click:function(){    var nums=this.data.num;    nums++;    if(nums%2==0){    var context = wx.createContext()    context.setStrokeStyle("#00ff00")    context.setLineWidth(5)    context.rect(0, 0, 200, 200)    context.stroke()    context.setStrokeStyle("#ff0000")    context.setLineWidth(2)    context.moveTo(160, 100)    context.arc(100, 100, 60, 0, 2 * Math.PI, true)    context.moveTo(140, 100)    context.arc(100, 100, 40, 0, Math.PI, false)    context.moveTo(85, 80)    context.arc(80, 80, 5, 0, 2 * Math.PI, true)    context.moveTo(125, 80)    context.arc(120, 80, 5, 0, 2 * Math.PI, true)    context.stroke()    }else{    var context = wx.createContext()    context.setStrokeStyle("#00ff00")    context.setLineWidth(5)    context.rect(0, 0, 200, 200)    context.stroke()    context.setStrokeStyle("#ff0000")    context.setLineWidth(2)    context.moveTo(160, 103)    context.arc(100, 100, 60, 0, 2 * Math.PI, true)    context.moveTo(59, 137)    context.arc(100, 135, 40, 3.2,  Math.PI, false)    context.moveTo(84, 83)    context.arc(80, 80, 5, 0, 2 * Math.PI, true)    context.moveTo(124, 79)    context.arc(120, 80, 5, 0, 2 * Math.PI, true)    context.stroke()    }     wx.drawCanvas({      canvasId: this.data.canvaid,      actions: context.getActions()     })    this.setData({      num:nums   })  },  onReady: function (e) {    var context = wx.createContext()    context.setStrokeStyle("#00ff00")    context.setLineWidth(5)    context.rect(0, 0, 200, 200)    context.stroke()    context.setStrokeStyle("#ff0000")    context.setLineWidth(2)    context.moveTo(160, 103)    context.arc(100, 100, 60, 0, 2 * Math.PI, true)    context.moveTo(59, 137)    context.arc(100, 135, 40, 3.2,  Math.PI, false)    context.moveTo(84, 83)    context.arc(80, 80, 5, 0, 2 * Math.PI, true)    context.moveTo(124, 79)    context.arc(120, 80, 5, 0, 2 * Math.PI, true)    context.stroke()    wx.drawCanvas({      canvasId: this.data.canvaid,      actions: context.getActions()     })  }})

这个对小程序的小白来说，也是很简单的，接下来给大家发效果图吧！
这里写图片描述
点击后的效果图（可以重复无限次数的点击哦）

若有不懂的地方，可以在下方评论，也可以扫描下方二维码进行讨论

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