// components/navBar.js
Component({
  options:{
    multipleSlots:true
  },

  /**
   * 组件的属性列表
   */
  properties:{
    back:{
      type:Boolean,
      value:false
    },
    backTitle:{
      type:String,
      value:''
    },
    background:{
      type:String,
      value:''
    },
    homeUrl:String
  },

  /**
   * 组件的初始数据
   */
  data: {
    statusBarHeight:0,
    navBarHeight:44,
    canBack:true
  },
  lifetimes:{
    attached(){
      const windowInfo = wx.getWindowInfo();
      this.setData({
        statusBarHeight:windowInfo.statusBarHeight
      });
      const pages = getCurrentPages();
      if(pages.length>1){
        this.setData({
          canBack:true
        })
      }else{
        this.setData({
          canBack:false
        })
      }
    }
  },
  /**
   * 组件的方法列表
   */
  methods: {
    back(){
      wx.navigateBack();
    },
    backHome(){
      wx.reLaunch({
        url: this.properties.homeUrl,
      })
    },
    getHeight(){
      return this.data.statusBarHeight + this.data.navBarHeight;
    }
  }
})