Android_Review_19

Intent using ShareCompat to share info via Gmail/ SMS

1. share

      import androidx.core.app.ShareCompat
   
   
      ShareIntent = ShareCompat.IntentBuilder.from(this)
                               .setText(getString(R.string.share_text, itemSold, revenue))
                               .setType("text/plain")
                               .intent
   

2. data loop

   private fun showNowItem(){
   
             
             // allItems is a listOf array.
   
              var newItem = allItems[0]
              
              
              // Loop
   
              for (i in allItems) {
   
                  if (itemSold >= i.startProductionAmount) {
                  
                      newItem = i // 迴圈的任何元素裝進 newItem 容器中
   
                  }
      
                  else break
              }
   
              // If the new data is actually different than the current data
              // update the data info
              
              if (newItem != nowItem) { // 倘若等號前後不相等則...
   
                  nowItem = newItem
   
                  binding.dessertButton.setImageResource(newItem.imageId)
                  binding.amountSold = newItem.startProductionAmount
                  binding.revenue = newItem.price
              }
   
     }
   

3. List

          // 資料類別確定了資料的型別，倘若呼叫 Item 時。
          
           data class Item (
   
                              val imageId: Int,
                              val price: Int,
                              val amount: Int
   
                          )
   
   
   
                    private val allItemFromZero = listOf(
   
                        Item(R.drawable.lollipop,55,0),
                        Item(R.drawable.marchmello, 45,0),
                        Item(R.drawable.oreo, 38, 0)
   
                    )
   

4. data opts

                 private var nowItem = allItems[0]
                 private var revenue = 0
                 private var itemSold = 0
   
                 
                 
                 //Update the amount & price
                 revenue += nowItem.price
                        
                 itemSold++
   

5. List opt

           // 建立集合或是陣列？
           data class Item (
   
                              val imageId: Int,
                              val price: Int,
                              val amount: Int
   
                          )
   
           // 建立集合
           private val allItemFromZero = listOf(
   
                   Item(R.drawable.lollipop,55,0),
                   Item(R.drawable.marchmello, 45,0),
                   Item(R.drawable.oreo, 38, 0)
   
            )
   
   
            // 建立容器
            var newItem = allItemFromZero[0]
   
            // 集合方法：隨機（）
            //也可呼叫 .first() 取值
            newItem = allItemFromZero.shuffled().last()
   

LiveData 則屬於泛型資料類別：https://ithelp.ithome.com.tw/articles/10239879 免除為龍蛇雜燴的集合工具做轉型運算的煩惱。

7. output