看了下小程序的画布功能，简单的使用了一下，用蹩脚的逻辑做了个 “弹啊弹，弹走鱼尾纹的小球”，一起来看下吧。过程不重要主要是画布的使用哦。（本来想传gif的来着，后来发现不会传，就传个图片吧，想看的自己下载下来玩呦）
先上图，后上代码了：
js:
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var winWidth = 0
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var winHeight = 0
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var diameter = 10
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var time = 0
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Page({
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data:{
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numX:1,
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numY:1
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},
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xy:{
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x:10,
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y:10
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},
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onLoad:function(options){
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wx.getSystemInfo({
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success: function(res) {
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console.log(res)
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winHeight = res.windowHeight;
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winWidth = res.windowWidth;
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}
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})
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},
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onReady:function(){
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for(var i=0;i<1;i++){
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time = (1+Math.random()*10)
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setInterval(this.move,time);
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console.log(time)
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}
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},
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move(){
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if(this.data.numX == 1){
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this.xy.x++
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}else{
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this.xy.x--
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}
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if(this.xy.x == winWidth-diameter){
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this.data.numX=2
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}
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if(this.xy.x == diameter){
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this.data.numX=1
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}
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if(this.data.numY == 1){
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this.xy.y++
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}else{
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this.xy.y--
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}
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if(this.xy.y == 400-diameter){
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this.data.numY=2
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}
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if(this.xy.y == diameter){
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this.data.numY=1
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}
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this.ballMove(this.xy.x,this.xy.y);
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},
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ballMove(x,y){
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var context = wx.createContext()
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context.setFillStyle("#FF4500")
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context.setLineWidth(2)
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context.arc(x, y, diameter, 0, 2 * Math.PI, true)
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context.fill()
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wx.drawCanvas({
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canvasId: 'ball',
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actions: context.getActions()
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})
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}
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})
wxml:
