fix(TreeSelect): use scroll-view to prevent page scroll event @rex-zsd (#867)

packages/tree-select/index.less

@@ -11,9 +11,7 @@
     left: 0;
     top: 0;
     bottom: 0;
-    overflow: scroll;
     background-color: @white;
-    -webkit-overflow-scrolling: touch;
   }
 
   &__nitem {
@@ -32,10 +30,10 @@
   }
 
   &__content {
+    width: 65%;
     padding: 0 15px;
     margin-left: 35%;
-    overflow: scroll;
-    -webkit-overflow-scrolling: touch;
+    box-sizing: border-box;
   }
 
   &__item {

packages/tree-select/index.wxml

@@ -2,7 +2,7 @@
   class="van-tree-select"
   style="height: {{ mainHeight }}px"
 >
-  <view class="van-tree-select__nav">
+  <scroll-view scroll-y class="van-tree-select__nav">
     <view
       wx:for="{{ items }}"
       wx:key="index"
@@ -12,8 +12,9 @@
     >
       {{ item.text }}
     </view>
-  </view>
-  <view
+  </scroll-view>
+  <scroll-view
+    scroll-y
     class="van-tree-select__content"
     style="height: {{ itemHeight }}px"
   >
@@ -31,5 +32,5 @@
         class="van-tree-select__selected"
       />
     </view>
-  </view>
+  </scroll-view>
 </view>