小程序picker自定义二级联动

项目中遇到只需要选择年月，找到一个三级联动的例子改的，保存一下

WXML

        {{multiArray[0][multiIndex[0]]}}{{multiArray[1][multiIndex[1]]}}

JS

data: {
    objectMultiShow:[],
    objectMultiArray:[],
    multiArray: [],
    multiIndex: [],
    multiIndex:[1,4],//默认显示的内容
  },
  onLoad: function (options) {
    let data = {
      objectMultiShow: this.data.objectMultiShow,
      objectMultiArray: this.data.objectMultiArray,
      multiArray: this.data.multiArray,
      multiIndex: this.data.multiIndex,    }
    data.objectMultiArray = [
      [{ id: 0, name: '2018年' }, { id: 1, name: '2019年' }],
      [
        { id: 0, name: '1月', parentId: 0 }, { id: 1, name: '2月', parentId: 0 }, { id: 2, name: '3月', parentId: 0 }, { id: 3, name: '4月', parentId: 0 }, { id: 4, name: '5月', parentId: 0 }, { id: 5, name: '6月', parentId: 0 }, { id: 6, name: '7月', parentId: 0 }, { id: 7, name: '8月', parentId: 0 }, { id: 8, name: '9月', parentId: 0 }, { id: 9, name: '10月', parentId: 0 }, { id: 10, name: '11月', parentId: 0 }, { id: 11, name: '12月', parentId: 0 },
        { id: 0, name: '1月', parentId: 1 }, { id: 1, name: '2月', parentId: 1 }, { id: 2, name: '3月', parentId: 1 }, { id: 3, name: '4月', parentId: 1 }, { id: 4, name: '5月', parentId: 1 }
      ],
    ]
    data.objectMultiShow = data.objectMultiArray.map((item, index) => {
      if (index > 0) {
        item = item.filter(i => i.parentId === data.objectMultiArray[index - 1][0].id)
      }
      return item
    })
    data.multiArray = data.objectMultiShow.map(item => {
      item = item.map(i => i.name)
      return item
    })
    console.log(data.multiIndex)
    // 数据更新
    this.setData(data)
  },

  bindMultiPickerChange: function (e) {
    console.log('picker发送选择改变，携带值为', e.detail.value)
    this.setData({
      multiIndex: e.detail.value
    })
  },
  bindMultiPickerColumnChange: function (e) {
    console.log('修改的列为', e.detail.column, '，值为', e.detail.value);
    // 初始化数据
    var data = {
      objectMultiShow: this.data.objectMultiShow,
      multiArray: this.data.multiArray,
      multiIndex: this.data.multiIndex
    };

    // 改变第i列数据之后，后几列选择第0个选项（重置）
    data.multiIndex[e.detail.column] = e.detail.value;
    for (let i = e.detail.column; i < data.multiIndex.length - 1; i++) {
      data.multiIndex[i + 1] = 0
    }
    let arry = this.data.objectMultiArray
    for (let i = e.detail.column; i < data.multiIndex.length - 1; i++) {
      data.objectMultiShow[i + 1] = arry[i + 1].filter(item => item.parentId === data.objectMultiShow[i][data.multiIndex[i]].id)
      data.multiArray[i + 1] = data.objectMultiShow[i + 1].map(item => item.name)
    }
    // 数据更新
    this.setData(data);
  },