小程序 开发之向左滑动实现删除功能

<!-- 自定义单选/多选/全选实现删除功能 -->
<view class="item-box">
    <view class="items">
        <view wx:for="{{list}}" wx:key="{{index}}" class="item">
            <view bindtouchstart="touchS" bindtouchmove="touchM" bindtouchend="touchE" data-index="{{index}}" style="{{item.txtStyle}}" class="inner txt">{{index+1}}.{{item.txt}}</view>
            <view data-index="{{index}}" bindtap= "delItem" class="inner del">删除</view>
        </view>
    </view>
</view>

/* 向左滑动实现删除操作 */
view{
    box-sizing: border-box;
}
.item-box{
    width: 700rpx;
    margin: 0 auto;
    padding:40rpx 0;
}
.items{
    width: 100%;
}
.item{
    position: relative;
    border-top: 2rpx solid #eee;
    height: 120rpx;
    line-height: 120rpx;
    overflow: hidden;
}
.item:last-child{
    border-bottom: 2rpx solid #eee;
}
.inner{
    position: absolute;
    top:0;
}
.inner.txt{
     font-family: Monaco;">#fff;
    width: 100%;
    z-index: 5;
    padding: 0 10rpx;
    transition: left 0.2s ease-in-out;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.inner.del{
     font-family: Monaco;">#e64340;
    width: 180rpx;
    text-align: center;
    z-index: 4;
    right: 0;
    color: #fff
}
.item-icon{
    width: 64rpx;
    height: 120rpx;
    vertical-align: middle;
    margin-right: 16rpx
}

// pages/leftSwiperDel/index.js
var app = getApp();
Page({
/**
* delBtnWidth: 删除按钮的宽度单位
* list: 循环的mock数据
* startX: 收支触摸开始滑动的位置
*/
    data: {
        delBtnWidth: 180,
        list: [],
        startX: ""
    },
    onLoad: function (options) {
        // 页面初始化 options为页面跳转所带来的参数
        this.initEleWidth();
    },
    onReady: function () {
        // 页面渲染完成
        var oDelList = app.globalData.delList;
        this.setData({
            list: oDelList
        })
    },
    onShow: function () {
    // 页面显示
    },
    onHide: function () {
    // 页面隐藏
    },
    onUnload: function () {
    // 页面关闭
    },
    touchS: function (e) {
        if (e.touches.length == 1) {
            this.setData({
                //设置触摸起始点水平方向位置
                startX: e.touches[0].clientX
            });
        }
    },
    touchM: function (e) {
        if (e.touches.length == 1) {
            //手指移动时水平方向位置
            var moveX = e.touches[0].clientX;
            //手指起始点位置与移动期间的差值
            var disX = this.data.startX - moveX;
            var delBtnWidth = this.data.delBtnWidth;
            var txtStyle = "";
            if (disX == 0 || disX < 0) {//如果移动距离小于等于0，说明向右滑动，文本层位置不变
                txtStyle = "left:0px";
            } else if(disX > 0){//移动距离大于0，文本层left值等于手指移动距离
                txtStyle = "left:-" + disX + "px";
            if (disX >= delBtnWidth) {
                //控制手指移动距离最大值为删除按钮的宽度
                txtStyle = "left:-" + delBtnWidth + "px";
            }
        }
        //获取手指触摸的是哪一项
        var index = e.currentTarget.dataset.index;
        var list = this.data.list;
        list[index].txtStyle = txtStyle;
        //更新列表的状态
        this.setData({
            list: list
        });
    }
},
    touchE: function (e) {
        if (e.changedTouches.length == 1) {
            //手指移动结束后水平位置
            var endX = e.changedTouches[0].clientX;
            //触摸开始与结束，手指移动的距离
            var disX = this.data.startX - endX;
            var delBtnWidth = this.data.delBtnWidth;
            //如果距离小于删除按钮的1/2，不显示删除按钮
            var txtStyle = disX > delBtnWidth / 2 ? "left:-" + delBtnWidth + "px" : "left:0px";
            //获取手指触摸的是哪一项
            var index = e.currentTarget.dataset.index;
            var list = this.data.list;
            list[index].txtStyle = txtStyle;
            //更新列表的状态
            this.setData({
                list: list
            });
        }
    },
    //获取元素自适应后的实际宽度
    getEleWidth: function (w) {
        var real = 0;
        try {
            var res = wx.getSystemInfoSync().windowWidth;
            var scale = (750 / 2) / (w / 2);//以宽度750px设计稿做宽度的自适应
            real = Math.floor(res / scale);
            return real;
        } catch (e) {
            return false;
            // Do something when catch error
        }
    },
    initEleWidth: function () {
        var delBtnWidth = this.getEleWidth(this.data.delBtnWidth);
        this.setData({
            delBtnWidth: delBtnWidth
        });
    },
    //点击删除按钮事件
    delItem: function (e) {
        //获取列表中要删除项的下标
        var index = e.currentTarget.dataset.index;
        var list = this.data.list;
        //移除列表中下标为index的项
        list.splice(index, 1);
        //更新列表的状态
        this.setData({
            list: list
        });
    },
})

const delList = [
{
txtStyle: "",
icon: "/images/icon0.png",
txt: "向左滑动可以删除"
},
{
txtStyle: "",
icon: "/images/icon6.png",
txt: "微信小程序|联盟（wxapp-union.com）"
},
{
txtStyle: "",
icon: "/images/icon1.png",
txt: "圣诞老人是爸爸，顺着烟囱往下爬，礼物塞满圣诞袜，平安糖果一大把"
},
{
txtStyle: "",
icon: "/images/icon2.png",
txt: "圣诞到来，元旦还会远吗？在圣诞这个日子里"
},
{
txtStyle: "",
icon: "/images/icon3.png",
txt: "圣诞节(Christmas或Cristo Messa ),译名为“基督弥撒”。"
},
{
txtStyle: "",
icon: "/images/icon4.png",
txt: "一年一度的圣诞节即将到来,姑娘们也纷纷开始跑趴了吧!"
},
 
{
txtStyle: "",
icon: "/images/icon5.png",
txt: "圣诞节(Christmas或Cristo Messa ),译名为“基督弥撒”。"
},
{
txtStyle: "",
icon: "/images/icon2.png",
txt: "你的圣诞节礼物准备好了吗?"
},
{
txtStyle: "",
icon: "/images/icon3.png",
txt: "一年一度的圣诞节即将到来,姑娘们也纷纷开始跑趴了吧!"
},
{
txtStyle: "",
icon: "/images/icon4.png",
txt: "圣诞到来，元旦还会远吗？"
},
{
txtStyle: "",
icon: "/images/icon5.png",
txt: "记下这一刻的心情"
},
];
export default {
delList
}