关于android:列表组件listview的使用flex布局教程以APICloud-AVM框架为例

71次阅读

共计 5690 个字符，预计需要花费 15 分钟才能阅读完成。

avm.js 是 APICloud 推出的多端开发框架。应用 avm.js 一个技术栈可同时开发 Android & iOS 原生 App、小程序和 iOS 轻 App，且多端渲染成果对立；全新的 App 引擎 3.0 不依赖 webView，提供百分百的原生渲染，保障 App 性能和体验与原生 App 统一。

list-view 定义可复用内容的竖向滚动视图，能够优化内存占用和渲染性能，反对下拉刷新和上拉加载。可应用 scroll-view 的根本属性。

list-view 外面可搁置 cell、list-header、list-footer、refresh 等组件，应用 cell 组件作为每项显示内容。

上面看一个 list-view 的示例：

<template>

<list-view id="listView" class="main" enable-back-to-top onscrolltolower={this.onscrolltolower}>
    <cell class="cell c-lc-rl_ac c-sy-border_bottom c-lc-ptb" onclick={this.itemClick}>
        <img class="img" src={item.url} alt="">
        <text class="title c-filling-w c-pl">{item.title}</text>
    </cell>
    <list-footer class="footer">
        <text> 加载中...</text>
    </list-footer>
</list-view></template><style src='../../css/c-layout-mini.css' scoped></style><style>.main {width: 100%;    height: 100%;

}.cell {width: 100%; height: 70px;
}.img {height: 50px; width: 50px; margin-left: 10px;
}.title {height: 50px; font-size: 20px; line-height: 50px;
}.footer {justify-content: center; align-items: center;
}</style><script>export default {name: ‘test’, methods: {

    apiready() {            this.initData(false);
    },
    initData(loadMore) {var that = this;            var skip = that.dataList ? that.dataList.length : 0;            var dataList = [];            for (var i = 0; i < 20; i++) {dataList[i] = {title: '我的项目' + (i + skip),                    url: '../../image/nav_tab_2.png'
            }
        }            var listView = document.getElementById('listView');            if (loadMore) {that.dataList = that.dataList.concat(dataList);
            listView.insert({data: dataList});
        } else {
            that.dataList = dataList;
            listView.load({data: dataList});
        }
    },
    onscrolltolower() {            this.initData(true);
    },
    itemClick(e) {api.alert({                msg: '以后项索引：' + e.currentTarget.index});
    }
}

}</script>
list-view 只反对 APP，须要用自定义 loader 或 APPloader 调试。调试教程可查看文档 APICloud Studio3 WiFi 真机同步和 WiFi 真机预览应用阐明

list-view 自带内存回收性能，能够滚动加载更多。

给 list-view 增加下拉刷新组件 refresh

依据 refresh 组件文档，把 refresh 标签增加到 list-view 标签中，如下:

<template>

<list-view id="listView" class="main" enable-back-to-top onscrolltolower={this.onscrolltolower}>
    <refresh class="refresh" state={refreshState} onstatechange={this.onstatechange}>
        <image class={refreshIconClass} src="../../image/refresh.png"></image>
        <image class={refreshLoadingClass} src="../../image/loading_more.gif"></image>
        <text class="refreshStateDesc">{refreshStateDesc}</text>
    </refresh>
    
    <cell class="cell c-lc-rl_ac c-sy-border_bottom c-lc-ptb" onclick={this.itemClick}>
        <img class="img" src={item.url} alt="">
        <text class="title c-filling-w c-pl">{item.title}</text>
    </cell>
    <list-footer class="footer">
        <text> 加载中...</text>
    </list-footer>
</list-view></template>

把 refresh 组件的 css，js 代码也复制到相应的 style 和 script 标签中，并在我的项目目录 image 标签下增加用到的两张下拉刷新图片。残缺代码如下：

<template>

<list-view id="listView" class="main" enable-back-to-top onscrolltolower={this.onscrolltolower}>
    <refresh class="refresh" state={refreshState} onstatechange={this.onstatechange}>
        <image class={refreshIconClass} src="../../image/refresh.png"></image>
        <image class={refreshLoadingClass} src="../../image/loading_more.gif"></image>
        <text class="refreshStateDesc">{refreshStateDesc}</text>
    </refresh>
    
    <cell class="cell c-lc-rl_ac c-sy-border_bottom c-lc-ptb" onclick={this.itemClick}>
        <img class="img" src={item.url} alt="">
        <text class="title c-filling-w c-pl">{item.title}</text>
    </cell>
    <list-footer class="footer">
        <text> 加载中...</text>
    </list-footer>
</list-view></template><style  src='../../css/c-layout-mini.css' scoped></style><style>.main {width: 100%;    height: 100%;

}.cell{width: 100%; height: 70px;
}.img{height: 50px; width: 50px; margin-left: 10px;
}.title {height: 50px; font-size: 20px; line-height: 50px;
} .footer {justify-content: center; align-items: center;

}    .refresh {align-items: center;        justify-content: center;        background-color: #eee;}    .refreshStateDesc {color: #e3007f;        font-size: 13px;}    .refreshIcon {position: absolute;        width: 25px;        height: 22px;        bottom: 21px;        left: 70px;        transition-property: transform;        transition-duration: 100ms;}    .refreshIcon-normal {transform: rotate(0);        visibility: visible;
}    .refreshIcon-dragging {transform: rotate(180deg);        visibility: visible;
}    .refreshIcon-refreshing {visibility: hidden;}    .refreshLoading {position: absolute;        width: 22px;        height: 22px;        bottom: 21px;        left: 70px;        visibility: hidden;}    .refreshLoading-refreshing {visibility: visible;}</style><script>
export default {        name: 'test',
     data(){            return {                refreshState: 'normal'}
    },        computed: {refreshIconClass(){if (this.data.refreshState == 'normal') {return 'refreshIcon refreshIcon-normal';} else if (this.data.refreshState == 'dragging') {return 'refreshIcon refreshIcon-dragging';} else if (this.data.refreshState == 'refreshing') {return 'refreshIcon refreshIcon-refreshing';}
        },
        refreshLoadingClass() {                if (this.data.refreshState == 'refreshing') {return 'refreshLoading refreshLoading-refreshing';} else {return 'refreshLoading';}
        },
        refreshStateDesc() {                if (this.data.refreshState == 'normal') {return '下拉能够刷新';} else if (this.data.refreshState == 'dragging') {return '松开能够刷新';} else if (this.data.refreshState == 'refreshing') {return '刷新中...';}
        }
    },        methods:{apiready() {this.initData(false);
        },
        initData(loadMore) {var that = this;                var skip = that.dataList?that.dataList.length:0;                var dataList = [];                for (var i=0;i<20;i++) {dataList[i] = {title: '我的项目' + (i + skip),                        url: '../../image/nav_tab_2.png'
                }
            }                var listView = document.getElementById('listView');                if (loadMore) {that.dataList = that.dataList.concat(dataList);
                listView.insert({data: dataList});
            } else {
                that.dataList = dataList;
                listView.load({data: dataList});
            }
        },
        onscrolltolower() {                this.initData(true);
        },
        itemClick(e) {api.alert({                    msg: '以后项索引：' + e.currentTarget.index});
        },
        onstatechange(e) {var state = e.detail.state;                if (state == 'normal') {this.data.refreshState = 'normal';} else if (state == 'dragging') {this.data.refreshState = 'dragging';} else if (state == 'refreshing') {                    this.data.refreshState = 'refreshing';                    var that = this;
                setTimeout(function(){that.data.refreshState = 'normal';}, 2000);
            }
        }
    }
}</script>

Flex 布局介绍：

Flex 布局意思是弹性盒子布局，比拟适宜挪动端场景，能够主动伸缩适配不同屏幕大小。

<div>

<div>item</div>

<div>item</div>

<div>item</div>

</div>

通常能够把父元素定义为弹性盒子或称为容器，其子元素为弹性盒子的我的项目。flex 布局的次要性能是在主轴或穿插轴按预期排列散布我的项目，定义每个我的项目占用空间比例，并可追随容器大小伸缩。

APICloud- 业余 APP 开发、app 定制服务商，提供一站式挪动利用解决方案，满足您的各类需要，欢送收费评估需要和获取报价。

正文完
android
发表至： android
2022-07-19
 0
关于android:程序员都以高薪人群被大家所关注程序员一年能挣多少钱你根本想不到
关于android:dex优化对Arouter查找路径的影响
关于android:基于CameraX完成拍照和拍视频
关于android:MobTech-秒验本机号码一键登录会泄露隐私吗