提交初始版本，使用vant ui库

miniprogram_npm/@vant/weapp/nav-bar/index.wxml

@@ -0,0 +1,42 @@
+<wxs src="../wxs/utils.wxs" module="utils" />
+<wxs src="./index.wxs" module="computed" />
+
+<view wx:if="{{ fixed && placeholder }}" style="height: {{ height }}px;" />
+
+<view
+  class="{{ utils.bem('nav-bar', { fixed }) }} custom-class {{ border ? 'van-hairline--bottom' : '' }}"
+  style="{{ computed.barStyle({ zIndex, statusBarHeight, safeAreaInsetTop }) }}; {{ customStyle }}"
+>
+  <view class="van-nav-bar__content">
+    <view class="van-nav-bar__left" bind:tap="onClickLeft">
+      <block wx:if="{{ leftArrow || leftText }}">
+        <van-icon
+          wx:if="{{ leftArrow }}"
+          size="16px"
+          name="arrow-left"
+          custom-class="van-nav-bar__arrow"
+        />
+        <view
+          wx:if="{{ leftText }}"
+          class="van-nav-bar__text"
+          hover-class="van-nav-bar__text--hover"
+          hover-stay-time="70"
+        >{{ leftText }}</view>
+      </block>
+      <slot wx:else name="left" />
+    </view>
+    <view class="van-nav-bar__title title-class van-ellipsis">
+      <block wx:if="{{ title }}">{{ title }}</block>
+      <slot wx:else name="title" />
+    </view>
+    <view class="van-nav-bar__right" bind:tap="onClickRight">
+      <view
+        wx:if="{{ rightText }}"
+        class="van-nav-bar__text"
+        hover-class="van-nav-bar__text--hover"
+        hover-stay-time="70"
+      >{{ rightText }}</view>
+      <slot wx:else name="right" />
+    </view>
+  </view>
+</view>