• tabbar显示购物车数量——微信小程序中自定义tabbar的一些坑


    效果如图,使用原生的方式为tabbar加上购物车数量

    在此处查看微信文档的自定义tabbar

    建议在开发者工具中预览效果

    首先在app.json中的tabBar项中加入配置: "custom": true

    然后加上 "usingComponents": {}

    在加上其他各项配置,这是我的app.json可用以参考

    {
      "pages": [
        "pages/index/index",
        "pages/category/index",
        "pages/shoppingCar/index",
        "pages/my/index",
        "pages/goodlist/goodlist",
        "pages/search/index",
        "pages/goodsdetail/index",
        "pages/orderconfirm/index",
        "pages/authorize/index"
      ],
      "window": {
        "backgroundTextStyle": "dark",
        "navigationBarBackgroundColor": "#ff2d4a",
        "navigationBarTitleText": "我的小程序",
        "navigationBarTextStyle": "white",
        "enablePullDownRefresh": true
      },
      "tabBar":{
        "custom": true,
         "color": "#7A7E83",
        "selectedColor": "#ff0000",
        "list": [
          {
            "pagePath": "pages/index/index",
            "text": "首页",
            "iconPath": "./images/icon_home@3x.png",
            "selectedIconPath": "./images/icon_home_active@3x.png"
          },
          {
            "pagePath": "pages/category/index",
            "text": "分页",
            "iconPath": "./images/icon_category@3x.png",
            "selectedIconPath": "./images/icon_category_active@3x.png"
          },
          {
            "pagePath": "pages/shoppingCar/index",
            "text": "购物车",
            "iconPath": "./images/icon_cart@3x.png",
            "selectedIconPath": "./images/icon_cart_active@3x.png"
          },
          {
            "pagePath": "pages/my/index",
            "text": "我的",
            "iconPath": "./images/icon_me@3x.png",
            "selectedIconPath": "./images/icon_me_active@3x.png"
          }
        ]
      },
      "usingComponents": {},
      "style": "v2",
      "sitemapLocation": "sitemap.json"
    }
    

    接下来在根目录创建custom-tab-bar文件夹(或者实例中的所有代码考过来)

    先完成页面与按钮的对应的配置使得tabbar能够点击跳转

    更改custom-tab-bar先index.js中的list配置如下(与app.json对应)

    注意注意,此处路径不可写 ./而是要根目录的/否则会报错

    Component({
     
      data: {
        selected: 1,
        color: "#7A7E83",
        selectedColor: "#ff0000",
        list: [
          {
            pagePath: "/pages/index/index",
            text: "首页",
            iconPath: "/images/icon_home@3x.png",
            selectedIconPath: "/images/icon_home_active@3x.png"
          },
          {
            pagePath: "/pages/category/index",
            text: "分页",
            iconPath: "/images/icon_category@3x.png",
            selectedIconPath: "/images/icon_category_active@3x.png"
          },
          {
            pagePath: "/pages/shoppingCar/index",
            text: "购物车",
            iconPath: "/images/icon_cart@3x.png",
            selectedIconPath: "/images/icon_cart_active@3x.png"
          },
          {
            pagePath: "/pages/my/index",
            text: "我的",
            iconPath: "/images/icon_me@3x.png",
            selectedIconPath: "/images/icon_me_active@3x.png"
          }
        ],
        shopping_count: (wx.getStorageSync('shopping_car') || [] ).length
      },
      methods: {
        switchTab(e) {
          const data = e.currentTarget.dataset
          const url = data.path
          wx.switchTab({url})
          this.setData({
            selected: data.index
          })
        }
      }
      
    
    })
    

    接下来在每个对应的页面写上如下代码

    其中selected为索引值,至此完成自定义tabbar的配置

    onShow() {
        if (typeof this.getTabBar === 'function' &&
          this.getTabBar()) {
          this.getTabBar().setData({
            selected: 0
          })
        }
      }
    

    接下来为购物车添加图标

    <!--miniprogram/custom-tab-bar/index.wxml-->
    <cover-view class="tab-bar">
      <cover-view class="tab-bar-border"></cover-view>
      <cover-view wx:for="{{list}}" wx:key="index" class="tab-bar-item" data-path="{{item.pagePath}}" data-index="{{index}}" bindtap="switchTab">
       
        <cover-image src="{{selected === index ? item.selectedIconPath : item.iconPath}}"></cover-image>
        <cover-view style="color: {{selected === index ? selectedColor : color}}">{{item.text}}</cover-view>
          <!-- 修改这行代码,其中index表示索引(我的购物车在第三个图标,索引为2) -->
         <cover-view class="shoppingCircle" wx:if="{{index === 2}}">{{shopping_count}}</cover-view>
      </cover-view>
    </cover-view>
    

    js文件中设置shopping_count变量如下

    shopping_count: (wx.getStorageSync('shopping_car') || [] ).length
    

    接着修改css中的内容使得页面呈现预期效果

    最后在shoppingcar页面中的onShow中定义函数使得作为操作后点击回来时可以改变显示的数字

    if (typeof this.getTabBar === 'function' &&
          this.getTabBar()) {
          this.getTabBar().setData({
            selected: 2
          })
        }
    
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  • 原文地址:https://www.cnblogs.com/axu1997/p/12686813.html
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