我想在request之后重置piker和textarea，请问该怎么做？设置什么值？

<view class='view_head'>

<view class='view_head_content'>

<picker class='pk' bindchange="bindPickerChange" value="{{stockindex}}" range='{{stockNos}}' range-key="{{'value'}}">

<view class="picker">{{stockNos[stockindex].value}}</view>

</picker>

</view>

<view class='view_head_content'>

<picker class='pk' mode="date" value="{{date}}" start="{{nowDate}}" end="{{endDate}}" bindchange="bindDateChange">

<view class="picker">{{date}}</view>

</picker>

</view>

<view class='view_head_content'>

<textarea class='txtarea' bindinput='remarkInput'></textarea>

</view>