Android_Review_13

RecyclerView 循環目錄清單

1. see codeScript as below. It is corresponding with UI https://github.com/QueenieCplusplus/Android_Review_9

        // go to app/src/main/java...../katesvideoapp/ui/Fragment.kt
   
        package com.example.android.katesvideoapp/ui
   
        [default module]
   
        [dataBind module]
        import com.example.android.katesvideoapp.R
        import com.example.android.katesvideoapp.databinding.KatesVideoAppItemBinding
        import com.example.android.katesvideoapp.databinding.FragmentKatesVideoAppBinding
   
        [intent module]
        import android.content.Intent
   
        [view module]
        import android.view.View
   
   
        [inflater module]
        import android.view.LayoutInflater
        import androidx.fragment.app.Fragment
        import android.view.ViewGroup
   
        [annotation module]
        import androidx.annotation.LayoutRes
   
        [Uri module]
        import android.net.Uri
   
        [observer module]
        import androidx.lifecycle.Observer
   
        [viewModel module]
        import androidx.lifecycle.viewModelProvider
   
        [recyclerView module]
        import androidx.recyclerview.widget.RecyclerView
        import androidx.recyclerview.widge.LinearLayout
   
        [data modules]
        import com.example.andorid.katesvideoapp.viewmodels.ViewModel
        import com.example.android.katesvideoapp.domain.Video
   
   
         // 定義碎片畫面的類別
        class KatesVideoAppFragment: Fragment(){
   
   
   
                // TODO:
                // declair and define val ViewModel 此客製化類別的實例 
                // declair and define val by lazy in its body 利用懶加載初始化內部唯讀資料
   
                // TODO:
                // declair and define 適配器變數可空
   
   
                // 碎片的生命週期之一
                override fun onViewCreated(v: View, savedInstanceState: Bundle?){
   
                    super.onViewCreated(v, savedInstanceState)
   
   
                }
   
                // 碎片的生命週期之一
                override fun OnCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
   
                    // TODO：
                    // infate the fragment
   
                }
   
                
                // TODO:
                // define a private fun for remind user about the sysError such as NetworkError
   
         
                // TODO:
                // using Uri to generate Links to Youtube
   
   
        }
        
        // TODO:
        class AfterVideoClick(){
            fun onClick(v: Video) = 
        }
        
        // 定義適配器的類別。參數為上述類別的輸出。
        class VideoAdpater(val cb: AfterVideoClick): RecyclerView.Adapter<VideoViewHolder>(){
        
        
                    // TODO:
                    // declair and define the items variable.
                    var videos: List<Video>
                    
                    // TODO
                    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): VideoViewHolder{
                         
                    }
                    
                    // TODO
                    override getItemCount() = videos.size
                    
                    // TODO
                    override fun onBindViewHolder(holder: VideoViewHolder, position: Int){
                    
                    
                    }
        
        }
        
        // 定義資料畫面目錄清單的欄位值資料抓取器
        class VideoViewHolder(val viewDataBinding: KatesVideoAppItemBinding): RecyclerView.ViewHolder(viewDataBinding.root){
        
                companion object {
                
                  val LAYOUT = R.layout.katesvideoapp_item
                
                }
        
        }
   

2. today's tip (lazy 懶加載)