Marquee effect of a small program development

Renderings

Code

1.app.js

//app.js
App({
  onLaunch: function () {
    console.log('App Launch')
  },
  onShow: function () {
    console.log('App Show')
  },
  onHide: function () {
    console.log('App Hide')
  },
  globalData: {
    hasLogin: false
  }
})

2. app.json

{
  "pages": [
    "pages/marquee/marquee",
    "pages/logs/logs"
  ],
  "window": {
    "backgroundTextStyle": "light",
    "navigationBarBackgroundColor": "#fff",
    "navigationBarTitleText": "WeChat",
    "navigationBarTextStyle": "black"
  },
  "style": "v2",
  "sitemapLocation": "sitemap.json"
}

3. marquee.js

Page({
  data: {
    text: '这是一条会滚动的文字滚来滚去的文字跑马灯，哈哈哈哈哈哈哈哈',
    marqueePace: 1,//滚动速度
    marqueeDistance: 0,//初始滚动距离
    marqueeDistance2: 0,
    marquee2copy_status: false,
    marquee2_margin: 60,
    size: 14,
    orientation: 'left',//滚动方向
    interval: 20 // 时间间隔
  },
  onShow: function () {
    // 页面显示
    var vm = this;
    var length = vm.data.text.length * vm.data.size;//文字长度
    var windowWidth = wx.getSystemInfoSync().windowWidth;// 屏幕宽度
    vm.setData({
      length: length,
      windowWidth: windowWidth,
      marquee2_margin: length < windowWidth ? windowWidth - length : vm.data.marquee2_margin//当文字长度小于屏幕长度时，需要增加补白
    });
    vm.run1();// 水平一行字滚动完了再按照原来的方向滚动
    vm.run2();// 第一个字消失后立即从右边出现
  },
  run1: function () {
    var vm = this;
    var interval = setInterval(function () {
      if (-vm.data.marqueeDistance < vm.data.length) {
        vm.setData({
          marqueeDistance: vm.data.marqueeDistance - vm.data.marqueePace,
        });
      } else {
        clearInterval(interval);
        vm.setData({
          marqueeDistance: vm.data.windowWidth
        });
        vm.run1();
      }
    }, vm.data.interval);
  },
  run2: function () {
    var vm = this;
    var interval = setInterval(function () {
      if (-vm.data.marqueeDistance2 < vm.data.length) {
        // 如果文字滚动到出现marquee2_margin=30px的白边，就接着显示
        vm.setData({
          marqueeDistance2: vm.data.marqueeDistance2 - vm.data.marqueePace,
          marquee2copy_status: vm.data.length + vm.data.marqueeDistance2 <= vm.data.windowWidth + vm.data.marquee2_margin,
        });
      } else {
        if (-vm.data.marqueeDistance2 >= vm.data.marquee2_margin) { // 当第二条文字滚动到最左边时
          vm.setData({
            marqueeDistance2: vm.data.marquee2_margin // 直接重新滚动
          });
          clearInterval(interval);
          vm.run2();
        } else {
          clearInterval(interval);
          vm.setData({
            marqueeDistance2: -vm.data.windowWidth
          });
          vm.run2();
        }
      }
    }, vm.data.interval);
  }
})

4. marquee.json

{
 "navigationBarTitleText": "跑马灯效果"
}

5. marquee.wxml

<!--pages/marquee/marquee.wxml-->
<view class="title">1 显示完后再显示</view>
<view class="example">
  <view class="marquee_box">
    <view class="marquee_text" style="{{orientation}}:{{marqueeDistance}}px;font-size: {{size}}px;">
      {{text}}
    </view>
  </view>
</view>
<view class="title">2 出现白边后即显示</view>
<view class="example">
  <view class="marquee_box">
    <view class="marquee_text" style="{{orientation}}:{{marqueeDistance2}}px;font-size: {{size}}px;">
      <text>{{text}}</text>
      <text wx:if="{{marquee2copy_status}}" style="margin-left:{{marquee2_margin}}px;">{{text}}</text>
    </view>
  </view>
</view>
<view class="marquee_panel">
 <view>
  <view>配置参数说明</view>
  <view>size：文字大小</view>
  <view>marqueePace：滚动速度</view>
  <view>interval：滚动时间间隔</view>
  <view>orientation：滚动方向</view>
  <view>marquee2_margin：2的白边长度</view>
 </view>
</view>

6. marquee.wxss

Page {
  background: #fff;
  overflow: hidden;
  line-height: 60rpx;
}

.example {
  display: block;
  width: 100%;
  height: 100rpx;
}

.marquee_box {
  width: 100%;
  position: relative;
}

.marquee_text {
  white-space: nowrap;
  position: absolute;
  top: 0;
}

.title {
  padding: 10rpx 20rpx;
  margin: 0 0 20rpx 0;
  border-left: 10rpx solid #ccc;
  font-size: 30rpx;
  background: #ececec;
}

.marquee_panel {
  margin: 20rpx 20rpx 20rpx 0;
  border-left: 10rpx solid #ccc;
  font-size: 26rpx;
}

.marquee_panel>view {
  padding: 30rpx;
  background: #ececec;
  border-radius: 0 20rpx 20rpx 0;
}