Android PopupWindow 彈出客製化視窗

PopupWindow應用的場景還是蠻多的，顯示在activity介面之上的任意彈出視窗基本上都可以用PopupWindow來實現。因為它可以顯示任意的View生成一个PopupWindow，最基本的三個條件是一定要設置的contentView,width,height。

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文章目錄

1. 自定義要顯示的Layout
2. 創建PopupWindow
3. PopupWindow添加動畫
4. PopupWindow顯示視窗位置
5. 程式範例
6. 效果展示

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1.自定義要顯示的Layout

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="wrap_content">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginEnd="32dp"
        android:background="#FF00FF"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:id="@+id/a"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="32dp"
            android:layout_marginEnd="32dp"
            android:background="#FF0000"
            android:gravity="center"
            android:text="A"
            android:textColor="@color/black"
            android:textSize="30sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:id="@+id/b"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:background="#FFFF00"
            android:gravity="center"
            android:text="B"
            android:textColor="@color/black"
            android:textSize="30sp"
            app:layout_constraintEnd_toEndOf="@+id/a"
            app:layout_constraintStart_toStartOf="@+id/a"
            app:layout_constraintTop_toBottomOf="@+id/a" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

2.創建PopupWindow(必要三個參數)

val popupWindow = PopupWindow(this).apply {
    contentView = myContentView
    width = ViewGroup.LayoutParams.MATCH_PARENT
    height = ViewGroup.LayoutParams.WRAP_CONTENT
}

3.PopupWindow添加動畫

創建anim資料夾

創建開啟動畫

<set xmlns:android="http://schemas.android.com/apk/res/android">
    <scale
        android:duration="500"
        android:fromXScale="0.5"
        android:fromYScale="0.5"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="1.0"
        android:toYScale="1.0" />
    <alpha
        android:duration="500"
        android:fromAlpha="0.0"
        android:toAlpha="1.0" />
</set>

創建關閉動畫

<set xmlns:android="http://schemas.android.com/apk/res/android">
    <scale
        android:duration="500"
        android:fromXScale="1.0"
        android:fromYScale="1.0"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="0.5"
        android:toYScale="0.5" />
    <alpha
        android:duration="500"
        android:fromAlpha="1.0"
        android:toAlpha="0.0" />
</set>

添加到Style

<resources xmlns:tools="http://schemas.android.com/tools">
    <style name="PopupAnimation" parent="android:Animation">
        <item name="android:windowEnterAnimation">@anim/popup_enter</item>
        <item name="android:windowExitAnimation">@anim/popup_exit</item>
    </style>
</resources>

4.PopupWindow顯示視窗位置

//自行設定位置
popupWindow.showAtLocation(view, Gravity.NO_GRAVITY, button.x.toInt(), button.y.toInt() - popupHeight)

//點擊View的下方
popupWindow.showAsDropDown(view)

5.程式範例

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val button = findViewById<Button>(R.id.button)

        button.setOnClickListener { view ->
            val myContentView = layoutInflater.inflate(R.layout.my_pop, null)
            myContentView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
            val popupHeight = myContentView.measuredHeight

            val popupWindow = PopupWindow(this).apply {
                contentView = myContentView
                width = ViewGroup.LayoutParams.MATCH_PARENT
                height = ViewGroup.LayoutParams.WRAP_CONTENT
                animationStyle = R.style.PopupAnimation
                //沒添加會一直創建新的
                isFocusable = true
                //透明背景
                setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
            }

            myContentView.findViewById<TextView>(R.id.a).setOnClickListener {
                Toast.makeText(this, "A", Toast.LENGTH_SHORT).show()
            }
            myContentView.findViewById<TextView>(R.id.b).setOnClickListener {
                Toast.makeText(this, "B", Toast.LENGTH_SHORT).show()
            }

            popupWindow.showAtLocation(view, Gravity.NO_GRAVITY, button.x.toInt(), button.y.toInt() - popupHeight)
            //popupWindow.showAsDropDown(view)
        }
    }
}

6.效果展示