PopupWindow(悬浮框)的基本使用

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <alpha android:fromAlpha="0"
        android:toAlpha="1"
        android:duration="2000">
    </alpha>
</set>

<?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="../style/images/ic_pop_bg"
    android:orientation="vertical">

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

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

</LinearLayout>

public class MainActivity extends AppCompatActivity {

    private Button btn_show;
    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = MainActivity.this;
        btn_show = (Button) findViewById(R.id.btn_show);
        btn_show.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                initPopWindow(v);
            }
        });
    }


    private void initPopWindow(View v) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.item_popup, null, false);
        Button btn_xixi = (Button) view.findViewById(R.id.btn_xixi);
        Button btn_hehe = (Button) view.findViewById(R.id.btn_hehe);
        //1.构造一个PopupWindow，参数依次是加载的View，宽高
        final PopupWindow popWindow = new PopupWindow(view,
                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, true);

        popWindow.setAnimationStyle(R.anim.anim_pop);  //设置加载动画

        //这些为了点击非PopupWindow区域，PopupWindow会消失的，如果没有下面的
        //代码的话，你会发现，当你把PopupWindow显示出来了，无论你按多少次后退键
        //PopupWindow并不会关闭，而且退不出程序，加上下述代码可以解决这个问题
        popWindow.setTouchable(true);
        popWindow.setTouchInterceptor(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return false;
                // 这里如果返回true的话，touch事件将被拦截
                // 拦截后 PopupWindow的onTouchEvent不被调用，这样点击外部区域无法dismiss
            }
        });
        popWindow.setBackgroundDrawable(new ColorDrawable(0x00000000));    //要为popWindow设置一个背景才有效


        //设置popupWindow显示的位置，参数依次是参照View，x轴的偏移量，y轴的偏移量
        popWindow.showAsDropDown(v, 50, 0);

        //设置popupWindow里的按钮的事件
        btn_xixi.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "你点击了嘻嘻~", Toast.LENGTH_SHORT).show();
            }
        });
        btn_hehe.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "你点击了呵呵~", Toast.LENGTH_SHORT).show();
                popWindow.dismiss();
            }
        });
    }
}