用setInterval 写倒计时 划动屏幕 安卓机严重卡顿  之前的类似轮播的一个功能也严重卡顿 ios很流畅  （问题模块只能选择时间）

.wxml <block wx:for="{{inks}}" wx:key=""> <image src="{{item.url}}"  mode='widthFix' style="width:{{item.width}}rpx;"></image></block> .js var para = [{ url:[], width:[] }]; var i=0; data: { imagepath:["../../images/ink1.png", "../../images/ink2.png", "../../images/ink3.png", "../../images/ink4.png"], inks: [{ url: [], width: [] }], }, 一个函数下面： para[i].url = that.data.imagepath[parseInt(Math.random() * 4)]  ; para[i].width = Math.random() ; i++; this.setData({ inks:para, }) 第一次i=0时进来就可以，第二次i=1时就报错：Cannot set property 'url' of undefined 请问，这是什么问题？

- 当前 Bug 的表现（可附上截图） - 预期表现 - 复现路径 - 提供一个最简复现 Demo [publib]:146 error run publib TypeError: Cannot read property 'toLowerCase' of undefined     at a.g ([publib]:1)     at new a ([publib]:1)     at [publib]:1     at Object.u [as onReady] ([publib]:1)     at Object.<anonymous> ([publib]:1)     at o ([publib]:1)     at i ([publib]:1)     at __waServiceInit__ ([publib]:1)     at __doWAServiceInit__ ([publib]:1)     at [publib]:1 value @ [publib]:146 [publib]:833 ReferenceError: define is not defined     at app.js:1     at ContextifyScript.Script.runInContext (vm.js:59)     at Object.runInContext (vm.js:120)     at loadCode ([publib]:827)     at handleInitUserCode ([publib]:811)     at handleSetupContext ([publib]:1221)     at handleProcessMessage ([publib]:1230)     at WebSocket.ws.on ([publib]:1458)     at emitOne (events.js:115)     at WebSocket.emit (events.js:210) loadCode @ [publib]:833 [publib]:833 ReferenceError: define is not defined     at canvasdrawer.js:1     at ContextifyScript.Script.runInContext (vm.js:59)     at Object.runInContext (vm.js:120)     at loadCode ([publib]:827)     at handleInitUserCode ([publib]:811)     at handleSetupContext ([publib]:1221)     at handleProcessMessage ([publib]:1230)     at WebSocket.ws.on ([publib]:1458)     at emitOne (events.js:115)     at WebSocket.emit (events.js:210) loadCode @ [publib]:833 [publib]:833 ReferenceError: define is not defined     at scan.js:1     at ContextifyScript.Script.runInContext (vm.js:59)     at Object.runInContext (vm.js:120)     at loadCode ([publib]:827)     at handleInitUserCode ([publib]:811)     at handleSetupContext ([publib]:1221)     at handleProcessMessage ([publib]:1230)     at WebSocket.ws.on ([publib]:1458)     at emitOne (events.js:115)     at WebSocket.emit (events.js:210) loadCode @ [publib]:833 [publib]:833 ReferenceError: define is not defined     at index.js:1     at ContextifyScript.Script.runInContext (vm.js:59)     at Object.runInContext (vm.js:120)     at loadCode ([publib]:827)     at handleInitUserCode ([publib]:811)     at handleSetupContext ([publib]:1221)     at handleProcessMessage ([publib]:1230)     at WebSocket.ws.on ([publib]:1458)     at emitOne (events.js:115)     at WebSocket.emit (events.js:210) loadCode @ [publib]:833