ViewModel LiveData 使用初体验

背景 Fragment 希望不用那么多代码在Fragment中。所以推出了ViewModel加载数据的方式。更加高度的解耦

生命周期

使用

  

   

    

     

    
    

     

      package com.anguomob.love.activity.ui.my
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import androidx.lifecycle.LiveData
     
    
   

    

     

    
    

     

      import androidx.lifecycle.MutableLiveData
     
    
   

    

     

    
    

     

      import androidx.lifecycle.ViewModel
     
    
   

    

     

    
    

     

      import com.anguomob.love.bean.UserInfo
     
    
   

    

     

    
    

     

      import com.anguomob.love.common.PassportManager
     
    
   

    

     

    
    

     

      import com.anguomob.love.net.usecase.PassportUseCase
     
    
   

    

     

    
    

     

      import io.reactivex.disposables.CompositeDisposable
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      class MyViewModel : ViewModel() {
     
    
   

    

     

    
    

     
    
      override 
      fun onCleared() {
     
    
   

    

     

    
    

     
        
      super.onCleared()
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
    
      private 
      val _text = MutableLiveData<UserInfo>()
     
    
   

    

     

    
    

     
    
      private 
      val _error = MutableLiveData<Throwable>()
     
    
   

    

     

    
    

     
    
      var dataList: LiveData<UserInfo> = _text
     
    
   

    

     

    
    

     
    
      var error: LiveData<Throwable> = _error
     
    
   

    

     

    
    

     
    
      val mDisposable: CompositeDisposable = CompositeDisposable()
     
    
   

    

     

    
    

     
    
      init {
     
    
   

    

     

    
    

     
        
      val subscribe =
     
    
   

    

     

    
    

     

                  PassportUseCase().refreshUserInfo(PassportManager.getInstance().getUid()).subscribe({
     
    
   

    

     

    
    

     

                      it?.let {
     
    
   

    

     

    
    

     

                          _text.value=it;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

                      }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

                  }, {
     
    
   

    

     

    
    

     

                      _error.value=it
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

                  })
     
    
   

    

     

    
    

     

              mDisposable.add(subscribe)
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      }
     
    
  

创建 ViewModel 类 并直接加载数据

在Fragment中需要的地方

initData里面把代码用上

    private lateinit var dashboardViewModel: MyViewModel

  

   

    

     

    
    

     

              dashboardViewModel =
     
    
   

    

     

    
    

     

                  ViewModelProvider(this).
      get(MyViewModel::
      class.java)
     
    
   

    

     

    
    

     

              dashboardViewModel.dataList.observe(viewLifecycleOwner, Observer {
     
    
   

    

     

    
    

     

                  it?.
      let {
     
    
   

    

     

    
    

     

                      PassportManager.getInstance().saveUserInfo(it)
     
    
   

    

     

    
    

     

                      Glide.
      with(this)
     
    
   

    

     

    
    

     

                          .load(it.avatar)
     
    
   

    

     

    
    

     

                          .placeholder(getDefaultPlace(it.sex))
     
    
   

    

     

    
    

     

                          .transition(DrawableTransitionOptions.withCrossFade())
     
    
   

    

     

    
    

     

                          .into(mIvFDUpload)
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

                      mTvFdNickName.text = it.nick_name;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

                  }
     
    
   

    

     

    
    

     

              })
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              dashboardViewModel.
      error.observe(viewLifecycleOwner, Observer {
     
    
   

    

     

    
    

     

                  it?.
      let {
     
    
   

    

     

    
    

     

                      TipsToast.showTips(activity, ApiErrorCodeDesc.getErrorMsg(it))
     
    
   

    

     

    
    

     

                  }
     
    
   

    

     

    
    

     

              })