<picker bindchange="bindPickerChange" value="{{index}}" range="{{array}}">
   <view class='choseQuestion' >
    {{choseQuestionBank}}
   </view>
  </picker>

Page({
 data:{
  array:['全部','计算机网络','算法','数据结构','linux'],
  type:0,
  choseQuestionBank:"点击选择"
 },
 bindPickerChange: function (e) {
  var that=this
  console.log('picker发送选择改变，携带值为', e.detail.value)
  this.setData({
   type: e.detail.value,
   choseQuestionBank: that.data.array[e.detail.value]
  })
 },
})