第8例：使用PopWindow实现菜单选择

核心思想知识点：
1）、PopWindow基本使用

效果图如下

GIF.gif

功能实现过程

1、popshow_anim.xml（PopWindow进入动画）

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <scale
        android:duration="100"
        android:fillAfter="false"
        android:fromXScale="1.0"
        android:fromYScale="0.0"
        android:interpolator="@android:anim/accelerate_decelerate_interpolator"
        android:pivotX="50%"
        android:pivotY="0%"
        android:toXScale="1.0"
        android:toYScale="1.0" >
    </scale>

</set>

2、pophidden_anim.xml（PopWindow退出动画）

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <scale
        android:duration="100"
        android:fillAfter="false"
        android:fromXScale="1.0"
        android:fromYScale="1.0"
        android:interpolator="@android:anim/accelerate_interpolator"
        android:pivotX="50%"
        android:pivotY="0%"
        android:toXScale="1.0"
        android:toYScale="0.0" >
    </scale>

</set>

3、styles.xml（样式资源）

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>
    <!-- 课程菜单栏 -->
    <style name="PopupWindowAnimation">
        <item name="android:windowEnterAnimation">@anim/popshow_anim</item>
        <item name="android:windowExitAnimation">@anim/pophidden_anim</item>
    </style>

    <style name="menu">
        <item name="android:layout_width">0dp</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:layout_weight">1</item>
        <item name="android:textColor">#000000</item>
        <item name="android:gravity">center</item>
        <item name="android:textSize">16dp</item>
    </style>
</resources>

4、pop_layout.xml（选择菜单布局）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:background="@color/colorPrimary"
    android:layout_height="wrap_content">
    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="测试"
        android:background="#ffffff"
        android:textSize="30sp"
        android:gravity="center"
        android:layout_margin="5dp"/>
</RelativeLayout>

5、activity_main.xml（主界面布局）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="课程分类"
                android:layout_centerInParent="true"
                android:textColor="#000000"
                android:textSize="22sp" />
           <ImageView
               android:layout_width="match_parent"
               android:layout_height="1dp"
               android:background="#000000"
               android:layout_alignParentBottom="true"/>
        </RelativeLayout>
        <LinearLayout
            android:id="@+id/button_group"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp">
            <TextView
            android:id="@+id/select_1"
            android:text="语言分类"
            style="@style/menu" />
            <ImageView
                android:layout_width="1dp"
                android:layout_height="match_parent"
                android:layout_marginTop="2dp"
                android:layout_marginBottom="2dp"
                android:background="#000000"/>
            <TextView
                android:id="@+id/select_2"
                android:text="类型"
                style="@style/menu" />
            <ImageView
                android:layout_width="1dp"
                android:layout_height="match_parent"
                android:layout_marginTop="2dp"
                android:layout_marginBottom="2dp"
                android:background="#000000"/>
            <TextView
                android:id="@+id/select_3"
                android:text="热门"
                style="@style/menu" />
            <ImageView
                android:layout_width="1dp"
                android:layout_height="match_parent"
                android:layout_marginTop="2dp"
                android:layout_marginBottom="2dp"
                android:background="#000000"/>
            <TextView
                android:id="@+id/select_4"
                android:text="难易"
                style="@style/menu" />
        </LinearLayout>
        <ImageView
            android:id="@+id/tag_line"
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="#000000"
            android:layout_alignParentBottom="true"/>
    </LinearLayout>
</RelativeLayout>

6、MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private static final String TAG = MainActivity.class.getSimpleName();
    private PopupWindow popupWindow;
    private ImageView tag_line;
    private TextView txt;
    private boolean isShow;
    private int index;
    private int oldIndex;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //初始化菜单项
        findViewById(R.id.select_1).setOnClickListener(this);
        findViewById(R.id.select_2).setOnClickListener(this);
        findViewById(R.id.select_3).setOnClickListener(this);
        findViewById(R.id.select_4).setOnClickListener(this);
        tag_line = (ImageView) findViewById(R.id.tag_line);
    }

    @Override
    public void onClick(View v) {
        String str = null;
        switch (v.getId()) {
            case R.id.select_1://全部分类
                str = "全部分类";
                index = 1;
                break;
            case R.id.select_2://类型
                str = "类型";
                index = 2;
                break;
            case R.id.select_3://热门
                str = "热门";
                index = 3;
                break;
            case R.id.select_4://难易
                str = "难易";
                index = 4;
                break;

        }
        setMenu(str);
    }
    /**
     * 设置
     */
    private void setMenu(String message) {
        if (null == popupWindow){
            View view = getLayoutInflater().inflate(R.layout.pop_layout, null);
            txt = (TextView) view.findViewById(R.id.text);
            //创建弹窗
            popupWindow = new PopupWindow(view, WindowManager.LayoutParams.MATCH_PARENT,
                    WindowManager.LayoutParams.WRAP_CONTENT);
            popupWindow.setAnimationStyle(R.style.PopupWindowAnimation);//设置动画效果
            popupWindow.setOutsideTouchable(false);//设置点击弹窗外部不关闭弹窗
            popupWindow.setFocusable(false);//设置不获取焦点
        }
        Log.d(TAG,"isShow================"+isShow);
        Log.d(TAG,"index================"+index);
        Log.d(TAG,"oldIndex================"+oldIndex);
        if (isShow){
            if (index == oldIndex){
                popupWindow.dismiss();//关闭弹窗
                isShow = false;
                return;
            }
        }
        txt.setText(message);
        popupWindow.showAsDropDown(tag_line);//设置显示弹窗
        isShow = true;
        oldIndex = index;
        txt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (popupWindow != null && popupWindow.isShowing()){
                    popupWindow.dismiss();
                    isShow = false;
                }
            }
        });
    }
}