【快应用】快应用学习之页面周期函数onBackPress无法触发？-编程知识

【快应用】快应用学习之页面周期函数onBackPress无法触发？

【关键词】

onBackPress、退出提示

【问题背景】

在学习和调试快应用的过程中，我在子页面中的onBackPress()函数中定制了退出的一个弹框提醒，将它作为组件引入父页面中，弹框却无法触发？
问题代码如下：
子页面

<template>
<!-- Only one root node is allowed in template. -->
<div class="container ">
<div class="mlr-container">
<input onclick="hasinstallShortcut" type="button" value="Check Shortcut Creation" class="btn-blue" />
</div>
<div class="mlr-container">
<input onclick="deeplink" type="button" value="Create Shortcut By Deeplink" class="btn-blue" />
</div>
<div class="mlr-container">
<input onclick="setShortcut" type="button" value="Create Shortcut" class="btn-blue" />
</div>
<div class="mlr-container">
<shortcut-button class="shortcut" add-type="5" onclick="click()"></shortcut-button>
</div>
<div class="mlr-container">
<input onclick="turnTo" type="button" value="Turn To My QuickApp" class="btn-blue" />
</div>
</div>
</template><style lang="sass">.container {flex-direction: column;justify-content: center;align-items: center;}.mlr-container {margin-top: 50px;margin-right: 30px;margin-left: 30px;flex-direction: column;}.btn-blue {background-color: #0faeff;color: #ffffff;width:600px;height: 150px;font-size: 50px;border-radius:15px;}.shortcut {margin-top: 40px;background-color: #0faeff;color: rgb(22, 203, 219);font-size: 40px;width: 500px;height: 100px;border-radius: 220px;align-self: center;text-align: center;opacity: 0.4;}
</style><script>import shortcut from '@system.shortcut';import prompt from '@system.prompt';import router from '@system.router'
module.exports = {onInit: function () {this.$page.setTitleBar({text: '创建桌面图标',backgroundColor: '#007DFF',backgroundOpacity: 0.5,});},setShortcut() {shortcut.install({message: 'Adds the shortcut to the desktop for convenient use next time.',success: function (ret) {console.log('handling createShortCut success');},fail: function (erromsg, errocode) {prompt.showToast({message: erromsg+errocode,duration: 2000,gravity: 'bottom'})}});},hasinstallShortcut() {shortcut.hasInstalled({success: function (ret) {console.log('hasInstalled success ret---' + ret);if (ret) {// 桌面图标已创建   prompt.showToast({message: 'has',})} else {// 桌面图标未创建prompt.showToast({message: 'has not',})}}.bind(this),fail: function (erromsg, errocode) {console.log('hasInstalled fail ret---' + erromsg);}.bind(this),complete: function () {}});},deeplink() {router.push({// uri: '/hello'uri: 'hap://app/com.yzhj.yicaiyipu'// uri: 'hwfastapp://com.yzhj.yicaiyipu'});},click(event) {console.log(event,event.eventStatusCode);prompt.showToast({message: event.eventMessage});},turnTo() {router.push({uri: `/homePage?package='com.huawei.QuickAppDemo'`// uri: 'hap://app/com.huawei.QuickAppDemo'// uri: 'hwfastapp://com.yzhj.yicaiyipu'});},onBackPress () {console.log("back!!")var that = thisshortcut.install({message: '我看你很喜欢这个应用呢，加个桌面再退出吧',success: function (ret) {console.log('添加成功');that.$app.exit()},fail: function (erromsg, errocode) {prompt.showToast({message: erromsg+errocode,duration: 2000,gravity: 'bottom'})}})return true},}</script>

父页面

<import name="shortcut" src="../Demo/demo.ux"></import>
<template>
<!-- Only one root node is allowed in template. -->
<div class="container">
<div>
<shortcut></shortcut>
</div>
</div>
</template><style>/* .container {flex-direction: column;justify-content:flex-end;align-items: center;}
</style><script>import shortcut from '@system.shortcut';import prompt from '@system.prompt';module.exports = {data: {componentData: {message: '点击跳转快应用',},},onInit() {this.$page.setTitleBar({text: '欢迎来到快应用',textColor: '#ffffff',backgroundColor: '#007DFF',backgroundOpacity: 0.5,menu: true});},}
</script>

控制台输出如下：