popupWindow

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void leoClick(View view) {
        View popupView = getLayoutInflater().inflate(R.layout.popup_view, null);
// 获取到Button对象，可以做相应的点击事件		
		 Button btn1 =popupView.findViewById(R.id.btn1);

        PopupWindow popupWindow = new PopupWindow(popupView,ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT,true);
        popupWindow.showAsDropDown(view);


    }
}

activity_main

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

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="leoClick"
        android:text="显示对话框" />

</LinearLayout>

popup_view

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@mipmap/ic_launcher"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:text="上海"
        android:textSize="18sp" />

    <Button
        android:id="@+id/btn2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:text="北京"
        android:textSize="18sp" />

</LinearLayout>