android - 使用 View 寻呼机的点动画

Question

我正在处理包含 ViewPager 的 FragmentActivity。 ViewPager 使用 FragmentPagerAdapter 提供了三个 fragment 。所以我能够使用 viewpager 实现滑动屏幕。我可以滑动页面并单击下一步按钮，我也可以移动到下一页/fragment 。以下代码对我有用:

1.WelcomeFragmentActivity.java

public class WelcomeFragmentActivity extends FragmentActivity {
    private List<Fragment> listFragments;

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

        //FindViewByID
        final ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
        Button btnNext = (Button) findViewById(R.id.btnNext);

        //Initializing the List
        listFragments = new ArrayList<Fragment>();

        //initializing the fragments
        WelcomeOneFragment welcomeOneFragment = new WelcomeOneFragment();
        WelcomeTwoFragment welcomeTwoFragment = new WelcomeTwoFragment();
        WelcomeThreeFragment welcomeThreeFragment = new WelcomeThreeFragment();

        //Adding Fragments to List
        listFragments.add(welcomeOneFragment);
        listFragments.add(welcomeTwoFragment);
        listFragments.add(welcomeThreeFragment);

        //initializing PagerAdapterWelcome
        PagerAdapterWelcome pagerAdapterWelcome = new PagerAdapterWelcome(getSupportFragmentManager(), listFragments);
        viewPager.setAdapter(pagerAdapterWelcome);

        //On clicking next button move to next fragment
        btnNext.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.e("Current position", String.valueOf(viewPager.getCurrentItem()));
                viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
                // If view pager is displaying the 3rd fragment ,move to WelcomeActivity
                if (viewPager.getCurrentItem() == 2) {
                    Log.e("Curent position", String.valueOf(viewPager.getCurrentItem()));
                    startActivity(new Intent(WelcomeFragmentActivity.this, WelcomeActivity.class));
                }
            }
        });

    }
}

2.PagerAdapterWelcome.java

public class PagerAdapterWelcome extends FragmentPagerAdapter {

    private List<Fragment> listFragments;


    public PagerAdapterWelcome(FragmentManager fm, List<Fragment> listFragments) {
        super(fm);
        this.listFragments = listFragments;
    }

    @Override
    public Fragment getItem(int i) {
        return listFragments.get(i);
    }

    @Override
    public int getCount() {
        return listFragments.size();
    }
}

我想实现以下屏幕:

滑动或单击下一步按钮后，这三个屏幕将依次显示。点的橙色告诉我当前正在处理哪个 fragment 。请指导我如何为这些点添加动画？

编辑代码

我已经使用 RadioGroup 来实现这个概念。考虑以下代码:

viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {
            position = viewPager.getCurrentItem();
            Log.e("Position", String.valueOf(position));
            if (position == 0)
                radioGroup.check(R.id.radioBtnOne);
            else if (position == 1) {
                radioGroup.check(R.id.radioBtnTwo);
            } else
                radioGroup.check(R.id.radioBtnThree);
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

它在某种程度上是有效的，但我没有得到设计中提到的确切颜色。请检查以下屏幕截图:

在 Ankit Aggrawal 建议向 radio biutton 添加一些样式后，我得到以下结果:

Answer 1

我通过使用 radiogroup 实现了这一点。使用相对布局将该 radio 组定位在您的 viewpager 上方。创建一个单选组，其中包含所需数量的点作为单选按钮。不要给单选按钮任何文本。

编辑: 下面是完整的工作代码。

像这样创建你的布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:orientation="horizontal"
        android:id="@+id/radioGroup">

        <RadioButton
            android:id="@+id/radioBtnOne"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:background="@drawable/button_selector"
            android:button="@null"/>

        <RadioButton
            android:id="@+id/radioBtnTwo"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:background="@drawable/button_selector"
            android:button="@null"/>

        <RadioButton
            android:id="@+id/radioBtnThree"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:background="@drawable/button_selector"
            android:button="@null"/>

    </RadioGroup>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

现在在 viewpager 中，放置一个 onPageChangeListener

viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                radioGroup.check(radioGroup.getChildAt(position).getId());
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

下面是单选按钮的选择器button_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
     <item
        android:state_checked="true"
        android:state_pressed="false"
        android:drawable="@drawable/toggle_button_selected"/>

    <item
        android:state_checked="false"
        android:state_pressed="false"
        android:drawable="@drawable/toggle_button_unselected"/>

    <item
        android:state_checked="true"
        android:state_pressed="true"
        android:drawable="@drawable/toggle_button_selected"/>

    <item
        android:state_checked="false"
        android:state_pressed="true"
        android:drawable="@drawable/toggle_button_unselected"/>

</selector>

现在为选中的按钮创建这个 toggle_button_selected_drawable.xml

<?xml version="1.0" encoding="utf-8" ?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <corners
        android:radius="10dp" />
    <solid
        android:color="@color/your_selection_color" />
</shape>

类似地为未选中的按钮创建这个 toggle_button_unselected_drawable.xml

<?xml version="1.0" encoding="utf-8" ?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <corners
        android:radius="10dp" />
    <solid
        android:color="@color/grey" />
</shape>