使用 Kotlin 在 Android 上加載活動后如何處理 GridView 項目

Question

我在 Kotlin 中有一個示例 android 應用程序。 在我的活動中，我在 gridview 中顯示了圖像，我希望它們隨機消失（或隨其他圖像更改），但我不知道在哪里編寫該代碼，因為 onStart 或 onResume 對我不起作用。

這是我的代碼：

class GameActivity : AppCompatActivity()
    {
        private var settings: Settings = Settings(1, 2, 2, 2)
        private var _settingsRepository: SettingsRepository? = null;
        private var _handler: Handler = Handler()
        private var _runnable: Runnable = Runnable {  }
        private var counter: Int = 0
        private var _adapter: GridElementAdapter? = null;
        private var _gridElementList: List<Item> = ArrayList<Item>()
        override fun onCreate(savedInstanceState: Bundle?)
        {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_game)
            _settingsRepository = SettingsRepository(this.applicationContext)
            settings = _settingsRepository!!.read()
            gridView.numColumns = settings.column
            gridView.setExpanded(true)
            val windowSize: Size = getGridSize()
            _gridElementList = getData()
            _adapter = GridElementAdapter(this, _gridElementList, settings, windowSize)
            gridView.adapter = _adapter;
        }
        override fun onStart()
        {
            super.onStart()
            hideElements()
            startCounter()
        }
        private fun hideElements()
        {
            if(gridView.adapter.count == 0)
            {
                return
            }
            var hideOrdder: ArrayList<Int> = ArrayList<Int>()
            for (i in 0 until gridView.adapter.count)
            {
                hideOrdder.add(i)
            }
            hideOrdder.shuffle()
            for (i in hideOrdder)
            {
                try
                {
                    var gridChild: Item = gridView.adapter.getItem(i) as Item
                    val element: Drawable? = getDrawable(gridChild.drawableId)
                    Thread.sleep((settings!!.speed * 100).toLong())
                }
                catch (e:Exception)
                {
                    print(e.localizedMessage)
                }
            }
        }
        private fun getData() : List<Item>
        {
            var gridElements: ArrayList<Item> = ArrayList<Item>()
            gridElements.add(Item("11", R.drawable.makk_asz))
            gridElements.add(Item("12", R.drawable.makk_kiraly))
            gridElements.add(Item("13", R.drawable.makk_felso))
            gridElements.add(Item("14", R.drawable.makk_also))
            gridElements.add(Item("15", R.drawable.makk_tizes))
            gridElements.add(Item("16", R.drawable.makk_kilences))
            gridElements.add(Item("17", R.drawable.makk_nyolcas))
            gridElements.add(Item("18", R.drawable.makk_hetes))
            gridElements.add(Item("21", R.drawable.piros_asz))
            gridElements.add(Item("22", R.drawable.piros_kiraly))
            gridElements.add(Item("23", R.drawable.piros_felso))
            gridElements.add(Item("24", R.drawable.piros_also))
            gridElements.add(Item("25", R.drawable.piros_tizes))
            gridElements.add(Item("26", R.drawable.piros_kilences))
            gridElements.add(Item("27", R.drawable.piros_nyolcas))
            gridElements.add(Item("28", R.drawable.piros_hetes))
            gridElements.add(Item("31", R.drawable.zold_asz))
            gridElements.add(Item("31", R.drawable.zold_kiraly))
            gridElements.add(Item("33", R.drawable.zold_felso))
            gridElements.add(Item("34", R.drawable.zold_also))
            gridElements.add(Item("35", R.drawable.zold_tizes))
            gridElements.add(Item("36", R.drawable.zold_kilences))
            gridElements.add(Item("37", R.drawable.zold_nyolcas))
            gridElements.add(Item("38", R.drawable.zold_hetes))
            gridElements.add(Item("41", R.drawable.tok_asz))
            gridElements.add(Item("42", R.drawable.tok_kiraly))
            gridElements.add(Item("43", R.drawable.tok_felso))
            gridElements.add(Item("44", R.drawable.tok_also))
            gridElements.add(Item("45", R.drawable.tok_tizes))
            gridElements.add(Item("46", R.drawable.tok_kilences))
            gridElements.add(Item("47", R.drawable.tok_nyolcas))
            gridElements.add(Item("48", R.drawable.tok_hetes))
            val count: Int = settings.column * settings.row
            gridElements.shuffle()
            return gridElements.take(count)
        }
        private fun startCounter()
        {
            _runnable = object : Runnable
            {
                override fun run()
                {
                    counter++
                    _handler.postDelayed(this, 1000)
                }
            }
            _handler.post(_runnable)
        }
        private fun stopCounter()
        {
            _handler.removeCallbacks(_runnable)
            counter = 0
        }
        private fun getGridSize() : Size
        {
            val displaymetrics = DisplayMetrics()
            windowManager.defaultDisplay.getMetrics(displaymetrics);
            val screenHeight = displaymetrics.heightPixels
            val screenWidth = displaymetrics.widthPixels
            val height: Int = ( (screenHeight) / settings!!.row * 0.8).toInt()
            val width: Int = ((screenWidth / settings!!.column) * 0.62).toInt()
            return Size(width, height)
        }
    }

class GridElementAdapter: BaseAdapter
{
    private var _gridElementList: List<Item> = ArrayList<Item>()
    private var _context: Activity? = null
    private var _settings: Settings? = null
    private var _dimension: Size? = null

    private var _loyoutInflater: LayoutInflater?  = null

    constructor(context: Activity, list: List<Item>, settings: Settings, dimension: Size) : super()
    {
        _context = context
        _gridElementList = list
        _settings = settings
        _dimension = dimension

        _loyoutInflater = LayoutInflater.from(context)
    }

    override fun getCount(): Int {
        return _gridElementList.size
    }

    override fun getItem(i: Int): Item
    {
        return _gridElementList[i]
    }

    override fun getItemId(i: Int): Long
    {
        return _gridElementList[i].drawableId.toLong()
    }

    override fun getView(i: Int, view: View?, viewGroup: ViewGroup?): View?
    {
        var v = view
        val picture: ImageView
        val name: TextView

        if (v == null)
        {
            v = _loyoutInflater!!.inflate(R.layout.grid_item, viewGroup, false)
            v.setTag(R.id.picture, v.findViewById(R.id.picture))
            v.setTag(R.id.text, v.findViewById(R.id.text))
            v.setId(R.id.text.toInt())
        }

        picture = v!!.getTag(R.id.picture) as ImageView
        name = v!!.getTag(R.id.text) as TextView

        val item = getItem(i)
        picture.setImageResource(item.drawableId)
        name.text = item.name

        return v
    }
}

class Item
{
    var name: String
    var drawableId: Int = 0

constructor(name: String, drawableId: Int)
{
    this.name = name
    this.drawableId = drawableId
}

}

活動游戲.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".GameActivity">

    <com.memorygame.components.GameGridView
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center|center_horizontal|fill_horizontal|center_vertical|fill_vertical"
        android:horizontalSpacing="2dp"
        android:isScrollContainer="false"
        android:stretchMode="columnWidth"
        android:verticalSpacing="5dp" />

    <LinearLayout
        android:id="@+id/counterLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_column="2"
        android:gravity="bottom"
        android:orientation="horizontal"
        android:visibility="visible">

        <TextView
            android:id="@+id/timeLabelTextView"
            android:layout_width="301dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="Eltelt idő"
            android:textAlignment="center"
            android:textSize="24sp" />

        <TextView
            android:id="@+id/timeTextView"
            android:layout_width="168dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="0"
            android:textAlignment="center"
            android:textSize="24sp"
            android:textStyle="bold" />
    </LinearLayout>
</LinearLayout>

網格項.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center_horizontal|fill_horizontal|center_vertical|fill_vertical">

    <com.memorygame.components.SquareImageView
        android:id="@+id/picture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="fitXY" />

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="#55000000"
        android:paddingLeft="10dp"
        android:paddingTop="15dp"
        android:paddingRight="10dp"
        android:paddingBottom="15dp"
        android:textColor="@android:color/white" />

</FrameLayout>

class GameGridView: GridView
{
    private var expanded: Boolean = false

    constructor(context: Context?): super(context)
    {}

    constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)
    {}

    constructor(context: Context?, attrs: AttributeSet?, defStyle: Int): super(context, attrs, defStyle)
    {}

    private fun isExpanded(): Boolean
    {
        return expanded
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int)
    {
        // HACK! TAKE THAT ANDROID!
        if (isExpanded())
        {
            // Calculate entire height by providing a very large height hint.
            // View.MEASURED_SIZE_MASK represents the largest height possible.
            val expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK, AT_MOST)
            super.onMeasure(widthMeasureSpec, expandSpec)
            val params: ViewGroup.LayoutParams = layoutParams
            params.height = measuredHeight
        }
        else
        {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        }
    }

    fun setExpanded(expanded: Boolean)
    {
        this.expanded = expanded
    }
}

class SquareImageView : androidx.appcompat.widget.AppCompatImageView
{
    constructor(context: Context) : super(context) {}
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs) {}
    constructor(context: Context, attrs: AttributeSet?, defStyle: Int) : super(context, attrs, defStyle) {}

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int)
    {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        setMeasuredDimension(measuredWidth, measuredWidth)
    }
}

我的問題是我不知道如何在 UI 初始化后隱藏網格中的圖像，以及最佳實踐是什么。

Answer 1

我建議將RecyclerView與GridLayoutManager一起使用。

然后您可以通過adapter.submitList(items)更新項目。