showCanvas(qrcode){
this.isShow = true
this.qrcode = qrcode
this.__init()
},
//初始化画布
async __init(){
uni.showLoading({
title: '加载中...',
mask: true
})
this.ctx = uni.createCanvasContext('my-canvas',this)
...
}
skywalker2020
- 发布：2020-09-22 11:06
- 更新：2020-12-23 09:43
- 阅读：2210
【报Bug】uni.createCanvasContext(canvasId, this)调用出错
分类：HBuilderX
产品分类： HbuilderX
PC开发环境操作系统： Windows
PC开发环境操作系统版本号： window10 专业版
HBuilderX版本号： 2.8.11
示例代码：
操作步骤：
调用showCanvas，就会出现上述bug
调用showCanvas，就会出现上述bug
预期结果：
海报分享功能正常， uni.createCanvasContext(canvasId, this)能调用
海报分享功能正常， uni.createCanvasContext(canvasId, this)能调用
实际结果：
uni.createCanvasContext(canvasId, this)调用出错
uni.createCanvasContext(canvasId, this)调用出错
bug描述：
在HBuilderX开发微信小程序，用到这个方法来处理海报分享功能。原来是没有任何问题的，过一段时间后突然发现这个功能不能用了，最后调查发现uni.createCanvasContext(canvasId, this)调用出错。具体错误如下：
VM377:1 [Vue warn]: Property or method "toJSON" is not defined on the instance but referenced during render. Make sure that this property is reactive, either in the data option, or for class-based components, by initializing the property. See: https://vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.
(found in pages/detail/detail.vue)
_callee$ @ zhangyu-qrcode-poster.js:159
asyncGeneratorStep @ zhangyu-qrcode-poster.js:123
(anonymous) @ zhangyu-qrcode-poster.js:123
(anonymous) @ zhangyu-qrcode-poster.js:123
init @ zhangyu-qrcode-poster.js:154
showCanvas @ zhangyu-qrcode-poster.js:151
Show 61 more frames
VM377:1 (in promise) MiniProgramError
Converting circular structure to JSON
--> starting at object with constructor 'Object'
--- property '_renderProxy' closes the circle
TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Object'
--- property '_renderProxy' closes the circle
at JSON.stringify (<anonymous>)
at Object.sync (http://127.0.0.1:32286/appservice/dev/asdebug.js:1:59384)
at Object.u [as beforeinvoke] (http://127.0.0.1:32286/appservice/dev__/asdebug.js:1:27949)
at Proxy.value (http://127.0.0.1:32286/appservice/appservice?t=1600742625621:1:2765)
at _callee$ (http://127.0.0.1:32286/appservice/components/zhangyu-qrcode-poster.js:203:39)
at tryCatch (http://127.0.0.1:32286/appservice/common/vendor.js:2260:44)
at Generator.invoke [as _invoke] (http://127.0.0.1:32286/appservice/common/vendor.js:2471:26)
at Generator.prototype.<computed> [as next] (http://127.0.0.1:32286/appservice/common/vendor.js:2308:25)
at asyncGeneratorStep (http://127.0.0.1:32286/appservice/components/zhangyu-qrcode-poster.js:147:30)
at _next (http://127.0.0.1:32286/appservice/components/zhangyu-qrcode-poster.js:160:15)
5 个回复
skywalker2020 (作者)
应该是小程序开发工具的问题，可以直接关掉了
skywalker2020 (作者)
VM377:1 [Vue warn]: Property or method "toJSON" is not defined on the instance but referenced during render. Make sure that this property is reactive, either in the data option, or for class-based components, by initializing the property. See:
at _callee$ (http://127.0.0.1:32286/appservice/components/zhangyu-qrcode-poster.js:203:39
调用uni.createCanvasContext(canvasId, this)出现
这个问题依然存在，但是不影响功能了
chenli
微信开发者工具版本多少，升级到最新的应该就不会了。
skywalker2020 (作者)
这个Vue warn的 问题在最新版还是存在， 版本号1.03.2009140
梦尋Junjie - 原来她有男朋友
我的也是