使用PopupWindow實現一個懸浮框，懸浮在Activity之上，顯示位置可以指定
首先創建pop_window.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="#bbbbbb"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toTopOf="@+id/tv_msg"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/tv_msg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toTopOf="@+id/linearLayout"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<LinearLayout
android:id="@+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
android:orientation="horizontal"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.625">
<Button
android:id="@+id/btn_cancel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="取消" />
<Button
android:id="@+id/btn_ok"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="確定" />
</LinearLayout>
</android.support.constraint.ConstraintLayout>
使用ConstraintLayout看起來比較麻煩，用拖拽還是很方便的。這里設置四個組件，兩個TextView，兩個Button
activity_main.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/btn_pop_window"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
android:text="pop_window"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
主界面放置一個按鈕。
MainActivity：
package com.fitsoft;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.PopupWindow;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Button button;
PopupWindow popupWindow;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.btn_pop_window);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
popupWindow.showAsDropDown(v);
}
});
//載入界面
View view = LayoutInflater.from(this).inflate(R.layout.pop_window, null);
{
TextView textView = view.findViewById(R.id.tv_title);
textView.setText("標題");
}
{
TextView textView = view.findViewById(R.id.tv_msg);
textView.setText("這里是popwindow的消息內容");
}
{
Button button = view.findViewById(R.id.btn_ok);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "您點擊了確定按鈕", Toast.LENGTH_SHORT).show();
popupWindow.dismiss();
}
});
}
{
Button button = view.findViewById(R.id.btn_cancel);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "您點擊了取消按鈕", Toast.LENGTH_SHORT).show();
popupWindow.dismiss();
}
});
}
//綁定
popupWindow = new PopupWindow(view, WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT);
}
}
這里調用了PopupWindow的構造方法：
/**
* <p>Create a new non focusable popup window which can display the
* <tt>contentView</tt>. The dimension of the window must be passed to
* this constructor.</p>
*
* <p>The popup does not provide any background. This should be handled
* by the content view.</p>
*
* @param contentView the popup's content
* @param width the popup's width
* @param height the popup's height
*/
public PopupWindow(View contentView, int width, int height) {
this(contentView, width, height, false);
}
綁定視圖，設置寬高...很好用...
最后用按鈕的點擊事件彈出窗口：
popupWindow.showAsDropDown(v);
效果圖：
左對齊，顯示在下方....調整一下彈出代碼，將剛剛的彈出代碼注釋掉，用下面的代碼替換：
popupWindow.showAtLocation(MainActivity.this.getWindow().getDecorView(),
Gravity.CENTER, 0, 0);
獲取頂級布局，設置居中顯示，x、y不偏移。
效果圖：