feat(cascader): support aria

src/cascader/cascader.wxml

@@ -8,12 +8,20 @@
     </view>
     <view class="{{name}}__close-btn" bind:tap="hide">
       <slot name="close-btn" />
-      <t-icon wx:if="{{closeBtn}}" size="24" name="close" />
+      <t-icon wx:if="{{closeBtn}}" aria-role="button" aria-label="关闭" size="24" name="close" />
     </view>
     <view class="{{name}}__content">
       <block wx:if="{{steps && steps.length}}">
         <view wx:if="{{theme == 'step'}}" class="{{name}}__steps">
-          <view wx:for="{{steps}}" wx:key="index" class="{{name}}__step" bind:tap="onStepClick" data-index="{{index}}">
+          <view
+            wx:for="{{steps}}"
+            wx:key="index"
+            class="{{name}}__step"
+            bind:tap="onStepClick"
+            data-index="{{index}}"
+            aria-role="{{ item === defaultOptionLabel ? 'text' : 'button' }}"
+            aria-label="{{ item === defaultOptionLabel ? item : '已选中,' + item  }}"
+          >
             <view
               class="{{name}}__step-dot {{name}}__step-dot--{{item !== defaultOptionLabel ? 'active' : ''}} {{name}}__step-dot--{{index === steps.length - 1 ? 'last' : ''}}"
             ></view>
@@ -29,9 +37,9 @@
           </t-tabs>
         </block>
       </block>
-      <view wx:if="{{ subTitles && subTitles[stepIndex] }}" class="{{name}}__options-title"
-        >{{subTitles[stepIndex]}}</view
-      >
+      <view wx:if="{{ subTitles && subTitles[stepIndex] }}" class="{{name}}__options-title">
+        {{subTitles[stepIndex]}}
+      </view>
       <view
         class="{{name}}__options-container"
         style="width: {{items.length + 1}}00vw; transform: translateX(-{{stepIndex}}00vw)"
@@ -44,7 +52,7 @@
           scroll-y
           scroll-top="{{scrollTopList[index]}}"
         >
-          <view class="cascader-radio-group-{{index}}">
+          <view class="cascader-radio-group-{{index}}" aria-hidden="{{ stepIndex !== index}}">
             <t-radio-group
               value="{{selectedValue[index]}}"
               keys="{{keys}}"