我想在ViewPager中添加3个底部点,像这样。

我使用FragmentActivity和支持库ViewPager。


当前回答

不需要那么多代码。

你可以只使用带有tablayout的viewpager来完成所有这些事情,而不需要编写太多代码。

你的主要布局:

<RelativeLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   android:layout_width="match_parent"
   android:layout_height="wrap_content">

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

   </android.support.v4.view.ViewPager>
   <android.support.design.widget.TabLayout
       android:id="@+id/tabDots"
       android:layout_alignParentBottom="true"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       app:tabBackground="@drawable/tab_selector"
       app:tabGravity="center"
       app:tabIndicatorHeight="0dp"/>
</RelativeLayout>

将你的UI元素按如下方式连接起来:

Java代码:

mImageViewPager = (ViewPager) findViewById(R.id.pager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabDots);
tabLayout.setupWithViewPager(mImageViewPager, true);

就这样,你可以开始了。

您需要在可绘制文件夹中创建以下xml资源文件。

tab_indicator_selected.xml

<?xml version="1.0" encoding="utf-8"?>
<shape
    android:innerRadius="0dp"
    android:shape="ring"
    android:thickness="4dp"
    android:useLevel="false"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/colorAccent"/>
</shape>

tab_indicator_default.xml

<?xml version="1.0" encoding="utf-8"?>
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
            android:innerRadius="0dp"
            android:shape="oval"
            android:thickness="2dp"
            android:useLevel="false">
            <solid android:color="@android:color/darker_gray"/>
    </shape>

tab_selector.xml

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

    <item android:drawable="@drawable/tab_indicator_selected"
          android:state_selected="true"/>

    <item android:drawable="@drawable/tab_indicator_default"/>
</selector>

感觉和我一样懒惰吗?好了,上面所有的代码都转换成一个库! 使用 在gradle中添加以下内容: 实现“com.chabbal: slidingdotsplash: 1.0.2” 将以下内容添加到您的活动或片段布局中。

<com.chabbal.slidingdotsplash.SlidingSplashView
        android:id="@+id/splash"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:imageResources="@array/img_id_arr"/>

在strings.xml中创建一个整数数组。

<integer-array name="img_id_arr">
   <item>@drawable/img1</item>
   <item>@drawable/img2</item>
   <item>@drawable/img3</item>
   <item>@drawable/img4</item>
</integer-array>

完成了! 额外的为了监听页面更改使用addOnPageChangeListener(监听器); Github链接。

其他回答

如果有人想要构建一个带有缩略图作为指示器的viewPager,可以选择使用这个库: 用于viewPager的ThumbIndicator,也可以将图像链接作为资源。

@Junaid提供的解决方案可以简化。 而不是创建一个选择器(tab_selector.xml),你可以简单地直接在TabLayout上设置绘图。

<com.google.android.material.tabs.TabLayout
        android:id="@+id/tabLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        app:tabBackground="@drawable/tab_indicator_default"
        app:tabIndicator="@drawable/tab_indicator_selected"
        app:tabIndicatorColor="<youColor>"
        app:tabIndicatorGravity="center"
        app:tabIndicatorHeight="8dp" />

app:tabIndicatorHeight与“tab_indicator_selected.xml”中的值保持一致。 按照这种方法,你可以保持TabLayout的默认动画。 通过编程,你必须将选项卡设置为所选:

object : ViewPager2.OnPageChangeCallback() {
    override fun onPageSelected(position: Int) {
        val tab = binding.tabLayout.getTabAt(position)
        binding.tabLayout.selectTab(tab, true)
    }
}

请注意,我使用了ViewPager2。应该有使用ViewPager的等效方法。

以下是我提出的解决方案。

由于我们只需要在视图分页器中显示一些图像,因此避免了使用片段的麻烦。 实现了视图页面指示器(底部的点没有任何额外的库或插件) 在视图页面指示器(圆点)的触摸上,页面导航也在发生。 请不要忘记在资源中添加您自己的图片。 请随意评论和改进它。

A)下面是我的activity_main.xml

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="schneider.carouseladventure.MainActivity">

    <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/viewpager"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:id="@+id/viewPagerIndicator"
        android:layout_width="match_parent"
        android:layout_height="55dp"
        android:layout_alignParentBottom="true"
        android:layout_marginTop="5dp"
        android:gravity="center">

        <LinearLayout
            android:id="@+id/viewPagerCountDots"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_centerHorizontal="true"
            android:gravity="center"
            android:orientation="horizontal" />

    </RelativeLayout>


</RelativeLayout>

B) pager_item.xml

<?xml version="1.0" encoding="utf-8"?>

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

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView" />
</LinearLayout>

C) MainActivity.java

import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener, View.OnClickListener {

    int[] mResources = {R.drawable.nature1, R.drawable.nature2, R.drawable.nature3, R.drawable.nature4,
            R.drawable.nature5, R.drawable.nature6
    };

    ViewPager mViewPager;
    private CustomPagerAdapter mAdapter;
    private LinearLayout pager_indicator;
    private int dotsCount;
    private ImageView[] dots;


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

        mViewPager = (ViewPager) findViewById(R.id.viewpager);
        pager_indicator = (LinearLayout) findViewById(R.id.viewPagerCountDots);
        mAdapter = new CustomPagerAdapter(this, mResources);
        mViewPager.setAdapter(mAdapter);
        mViewPager.setCurrentItem(0);
        mViewPager.setOnPageChangeListener(this);

        setPageViewIndicator();

    }

    private void setPageViewIndicator() {

        Log.d("###setPageViewIndicator", " : called");
        dotsCount = mAdapter.getCount();
        dots = new ImageView[dotsCount];

        for (int i = 0; i < dotsCount; i++) {
            dots[i] = new ImageView(this);
            dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));

            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.WRAP_CONTENT,
                    LinearLayout.LayoutParams.WRAP_CONTENT
            );

            params.setMargins(4, 0, 4, 0);

            final int presentPosition = i;
            dots[presentPosition].setOnTouchListener(new View.OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    mViewPager.setCurrentItem(presentPosition);
                    return true;
                }

            });


            pager_indicator.addView(dots[i], params);
        }

        dots[0].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
    }

    @Override
    public void onClick(View v) {

    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {

        Log.d("###onPageSelected, pos ", String.valueOf(position));
        for (int i = 0; i < dotsCount; i++) {
            dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
        }

        dots[position].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));

        if (position + 1 == dotsCount) {

        } else {

        }
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
}

D) CustomPagerAdapter.java

 import android.content.Context;
    import android.support.v4.view.PagerAdapter;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ImageView;
    import android.widget.LinearLayout;

    public class CustomPagerAdapter extends PagerAdapter {
        private Context mContext;
        LayoutInflater mLayoutInflater;
        private int[] mResources;

        public CustomPagerAdapter(Context context, int[] resources) {
            mContext = context;
            mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            mResources = resources;
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {

            View itemView = mLayoutInflater.inflate(R.layout.pager_item,container,false);
            ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
            imageView.setImageResource(mResources[position]);
           /* LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(950, 950);
            imageView.setLayoutParams(layoutParams);*/
            container.addView(itemView);
            return itemView;
        }

        @Override
        public void destroyItem(ViewGroup collection, int position, Object view) {
            collection.removeView((View) view);
        }

        @Override
        public int getCount() {
            return mResources.length;
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }
    }

E) selecteditem_dot.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval" android:useLevel="true"
    android:dither="true">

    <size android:height="12dip" android:width="12dip"/>

    <solid android:color="#7e7e7e"/>
</shape>

F) nonselecteditem_dot.xml

 <?xml version="1.0" encoding="utf-8"?>
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval" android:useLevel="true"
        android:dither="true">        
        <size android:height="12dip" android:width="12dip"/>        
        <solid android:color="#d3d3d3"/>
    </shape>

自2012年以来,ViewPagerIndicator一直没有更新,并得到了几个从未修复的错误。

我终于找到了一个替代的光库,显示漂亮的点为viewpager,这里是链接:

https://github.com/ongakuer/CircleIndicator

易于实施!

下面是我如何做到这一点,有点类似于上面的解决方案。只要确保在下载完所有图像后调用loadDots()方法即可。

    private int dotsCount;
    private TextView dotsTextView[];

    private void setupAdapter() {
        adapter = new SomeAdapter(getContext(), images);
        viewPager.setAdapter(adapter);
        viewPager.setCurrentItem(0);
        viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
    }

    private final ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}

        @Override
        public void onPageSelected(int position) {
            for (int i = 0; i < dotsCount; i++)
                dotsTextView[i].setTextColor(Color.GRAY);

            dotsTextView[position].setTextColor(Color.WHITE);
        }

        @Override
        public void onPageScrollStateChanged(int state) {}
    };

    protected void loadDots() {
        dotsCount = adapter.getCount();
        dotsTextView = new TextView[dotsCount];
        for (int i = 0; i < dotsCount; i++) {
            dotsTextView[i] = new TextView(getContext());
            dotsTextView[i].setText(R.string.dot);
            dotsTextView[i].setTextSize(45);
            dotsTextView[i].setTypeface(null, Typeface.BOLD);
            dotsTextView[i].setTextColor(android.graphics.Color.GRAY);
            mDotsLayout.addView(dotsTextView[i]);
        }
        dotsTextView[0].setTextColor(Color.WHITE);
    }

XML

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="180dp"
        android:background="#00000000"/>


    <ImageView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/introImageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <LinearLayout
        android:id="@+id/image_count"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#00000000"
        android:gravity="center|bottom"
        android:orientation="horizontal"/>
</FrameLayout>