feat:重构按钮和icon组件

miniprogram/components3.0/nav-bar/nav-bar.json

@@ -1,3 +1,5 @@
 {
-    "component": true
+    "component": true,
+    "styleIsolation": "apply-shared",
+    "addGlobalClass": true
 }

miniprogram/components3.0/nav-bar/nav-bar.less

@@ -1,4 +1,5 @@
-@import '../../style/theme3.less';
+@import '../../style/theme.less';
+@import '../../assets/fonts/iconfont.less';
 
 .nav-bar {
     position: fixed;
@@ -22,6 +23,21 @@
     box-sizing: border-box;
 }
 
+.nav-bar__back {
+    width: 64rpx;
+    height: 64rpx;
+    display: flex;
+    align-items: center;
+    justify-content: flex-start;
+    flex-shrink: 0;
+}
+
+.nav-bar__back-icon {
+    font-size: 40rpx;
+    color: @color-nav-title;
+    line-height: 1;
+}
+
 .nav-bar__title {
     font-size: @fs-nav-title;
     font-weight: @fw-nav-title;
@@ -41,4 +57,4 @@
 .nav-bar__placeholder {
     width: 100%;
     flex-shrink: 0;
-}
+}

miniprogram/components3.0/nav-bar/nav-bar.ts

@@ -9,13 +9,25 @@ Component({
     data: {
         statusBarHeight: 0,
         navBlockHeight: 0,
+        showBackButton: false,
     },
     lifetimes: {
         attached() {
             const { statusBarHeight } = wx.getWindowInfo();
+            const pages = getCurrentPages();
             this.setData({
                 statusBarHeight,
                 navBlockHeight: statusBarHeight + NAV_INNER_PX,
+                showBackButton: pages.length > 1,
+            });
+        },
+    },
+    methods: {
+        handleBack() {
+            wx.navigateBack({
+                fail: () => {
+                    wx.switchTab({ url: '/pages/home/home' });
+                },
             });
         },
     },

miniprogram/components3.0/nav-bar/nav-bar.wxml

@@ -1,5 +1,11 @@
 <view class="nav-bar" style="padding-top: {{statusBarHeight}}px; {{background ? 'background:' + background + ';' : ''}}">
     <view class="nav-bar__inner">
+        <view
+            wx:if="{{showBackButton}}"
+            class="nav-bar__back"
+            bindtap="handleBack">
+            <text class="toy-icon toy-icon-arrow-left nav-bar__back-icon"></text>
+        </view>
         <slot name="left"></slot>
         <text class="nav-bar__title">{{title}}</text>
         <view class="nav-bar__right">