如何创建带有点指示器的 Android View Pager？

Question

可能你们中的许多人（如我）在创建带有底部圆点的ViewPager 时遇到问题，如下所示：

如何创建这样的 Android ViewPager？

Answer 1

我们只需要：ViewPager、TabLayout 和 2 个用于选定点和默认点的可绘制对象。

首先，我们必须将TabLayout 添加到我们的屏幕布局中，并将其与ViewPager 连接起来。我们可以通过两种方式做到这一点：

---

嵌套在TabLayout 中ViewPager

<androidx.viewpager.widget.ViewPager
    android:id="@+id/photos_viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.tabs.TabLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</androidx.viewpager.widget.ViewPager>

在这种情况下TabLayout 将自动与ViewPager 连接，但TabLayout 将在ViewPager 旁边，而不是在它之上。

---

单独的TabLayout

<androidx.viewpager.widget.ViewPager
    android:id="@+id/photos_viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

<com.google.android.material.tabs.TabLayout
    android:id="@+id/tab_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

在这种情况下，我们可以将TabLayout 放在任何地方，但我们必须以编程方式将TabLayout 与ViewPager 连接起来

ViewPager pager = (ViewPager) view.findViewById(R.id.photos_viewpager);
PagerAdapter adapter = new PhotosAdapter(getChildFragmentManager(), photosUrl);
pager.setAdapter(adapter);

TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(pager, true);

创建布局后，我们必须准备点。所以我们创建了三个文件：selected_dot.xml、default_dot.xml 和 tab_selector.xml。

---

selected_dot.xml

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

---

default_dot.xml

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

---

tab_selector.xml

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

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

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

---

现在我们只需要在 XML 布局中的 TabLayout 中添加 3 行代码。

app:tabBackground="@drawable/tab_selector"
app:tabGravity="center"
app:tabIndicatorHeight="0dp"

Answer 2

首先创建一个布局，其中为显示在您的视图分页器上的点提供一个 LinerLayout

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

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


    <LinearLayout
        android:id="@+id/pager_dots"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="10dp"
        android:background="@android:color/transparent"
        android:gravity="center_horizontal"
        android:orientation="horizontal">
    </LinearLayout>

</RelativeLayout>

之后创建 2 个可绘制对象

1.未选中的可绘制对象

<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="oval" xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@android:color/transparent"/>
    <size android:width="12dp" android:height="12dp"/>

    <stroke android:width="1dp" android:color="#ffffff"/>
</shape>

2。选定的可绘制对象

<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="oval" xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@android:color/transparent"/>
    <size android:width="12dp" android:height="12dp"/>

    <stroke android:width="1dp" android:color="#000000"/>
</shape>

之后设置适配器

private LinearLayout llPagerDots;
private ViewPager viewPager;
private ArrayList<String> eventImagesUrl;
private HomeViewPagerAdapter homeViewPagerAdapter;
private ImageView[] ivArrayDotsPager;

public void setUpViewPager() {
    viewPager = (ViewPager) findViewById(R.id.view_pager);
    llPagerDots = (LinearLayout) findViewById(R.id.pager_dots);

    homeViewPagerAdapter = new HomeViewPagerAdapter(mContext, eventImagesUrl);

    viewPager.setAdapter(homeViewPagerAdapter);

    setupPagerIndidcatorDots();

    ivArrayDotsPager[0].setImageResource(R.drawable.page_indicator_selected);

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

        }

        @Override
        public void onPageSelected(int position) {
            for (int i = 0; i < ivArrayDotsPager.length; i++) {
                ivArrayDotsPager[i].setImageResource(R.drawable.page_indicator_unselected);
            }
            ivArrayDotsPager[position].setImageResource(R.drawable.page_indicator_selected);
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });
}

创建方法 setupPagerIndidcatorDots() ：

private void setupPagerIndidcatorDots() {
    ivArrayDotsPager = new ImageView[eventImagesUrl.size()];
    for (int i = 0; i < ivArrayDotsPager.length; i++) {
        ivArrayDotsPager[i] = new ImageView(getActivity());
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        params.setMargins(5, 0, 5, 0);
        ivArrayDotsPager[i].setLayoutParams(params);
        ivArrayDotsPager[i].setImageResource(R.drawable.page_indicator_unselected);
        //ivArrayDotsPager[i].setAlpha(0.4f);
        ivArrayDotsPager[i].setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                view.setAlpha(1);
            }
        });
        llPagerDots.addView(ivArrayDotsPager[i]);
        llPagerDots.bringToFront();
    }

Answer 3

您可以查看我的图书馆来处理您的请求：https://github.com/tommybuonomo/dotsindicator

在您的 XML 布局中

  <com.tbuonomo.viewpagerdotsindicator.DotsIndicator
      android:id="@+id/dots_indicator"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      app:dotsColor="@color/colorPrimary"
      app:dotsSize="16dp"
      app:dotsWidthFactor="3"
      />

在您的 Java 代码中

dotsIndicator = (DotsIndicator) findViewById(R.id.dots_indicator);
viewPager = (ViewPager) findViewById(R.id.view_pager);
adapter = new ViewPagerAdapter();
viewPager.setAdapter(adapter);
dotsIndicator.setViewPager(viewPager);

Answer 4

当您想要使用最新的 ViewPager2 和 Kotlin

进行类似的操作时

一切不言自明，无需解释！

1.您的活动或片段

val imageList = listOf(
        ImageModel(R.drawable.offer1),
        ImageModel(R.drawable.splash),
        ImageModel(R.drawable.offer1),
        ImageModel(R.drawable.splash2)
    )

    val adapter = HomeOffersAdapter()
    adapter.setItem(imageList)
    photos_viewpager.adapter = adapter

    TabLayoutMediator(tab_layout, photos_viewpager) { tab, position ->
    }.attach()
}

2。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="@dimen/dp_200">

<androidx.viewpager2.widget.ViewPager2
    android:id="@+id/photos_viewpager"
    android:layout_width="match_parent"
    android:layout_height="@dimen/dp_200" />

<com.google.android.material.tabs.TabLayout
    android:id="@+id/tab_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_gravity="bottom|center"
    app:tabBackground="@drawable/tab_selector"
    app:tabGravity="center"
    app:tabIndicatorHeight="0dp"
    app:tabSelectedTextColor="@android:color/transparent"
    app:tabTextColor="@android:color/transparent" />

3.可绘制：tab_selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/dot_selected" android:state_selected="true" />
<item android:drawable="@drawable/dot_default" />

4.可绘制：dot_selected.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadius="0dp"
android:shape="ring"
android:thickness="@dimen/dp_8"
android:useLevel="false">

<solid android:color="@color/colorPrimary" />

<stroke
    android:width="@dimen/dp_1"
    android:color="@android:color/white" />

5.可绘制：dot_default.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadius="0dp"
android:shape="ring"
android:thickness="@dimen/dp_8"
android:useLevel="false">

<solid android:color="@android:color/transparent" />

<stroke
    android:width="@dimen/dp_1"
    android:color="@android:color/white" />

6.适配器

class HomeOffersAdapter : RecyclerView.Adapter<HomeOffersAdapter.HomeOffersViewHolder>() {

private var list: List<ImageModel> = listOf()


override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HomeOffersViewHolder {
    return HomeOffersViewHolder(parent)
}


override fun onBindViewHolder(holder: HomeOffersViewHolder, position: Int) {
    holder.bind(list[position])
}

fun setItem(list: List<ImageModel>) {
    this.list = list
    notifyDataSetChanged()
}

override fun getItemCount(): Int = list.size

class HomeOffersViewHolder constructor(itemView: View) : RecyclerView.ViewHolder(itemView) {

    constructor(parent: ViewGroup) : this(
        LayoutInflater.from(parent.context).inflate(
            R.layout.pager_item,
            parent, false
        )
    )

    fun bind(imageModel: ImageModel) {
        itemView.offerImage.setImageResource(imageModel.image)
    }
}

}

7.布局：pager_item.xml

<LinearLayout 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:fitsSystemWindows="true"
android:orientation="vertical">

<androidx.appcompat.widget.AppCompatImageView
    android:id="@+id/offerImage"
    android:layout_width="match_parent"
    android:layout_height="@dimen/dp_200"
    android:adjustViewBounds="true"
    android:scaleType="fitXY"
    tools:src="@drawable/offer1" />

Answer 5

2021，如何实际做到这一点。仅限 ViewPager2。

参考这篇优秀的短文，有几个问题：

https://medium.com/@adrian.kuta93/android-viewpager-with-dots-indicator-a34c91e59e3a

从 2021 年开始的普通 Android Studio 默认项目开始，具有相当新的最小值（目前为 24 个）...

一般概念：

制作一个标准的 TabLayout，但将每个“标签单元”替换为“一个小点”而不是通常的文本。

在 TabLayout 中，您确实可以使用“tabBackground”替换每个“标签单元”：

        app:tabBackground="@drawable/tab_selector"

因此，将以下内容添加到具有 ViewPager2 的屏幕的 XML 中：

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|center"
        android:background="#00FFFFFF"
        app:tabBackground="@drawable/tab_selector"
        app:tabIndicatorGravity="center"
        app:tabIndicatorHeight="0dp"/>

请注意，我们正在将 TabLayout 中的每一个“标签单元”替换为我们自己的 “tab_selector”。

明确地说，“tabBackground”是指单个小“标签单元”，不是整个标签栏系统。

（另外，请注意 tabIndicatorGravity 和 tabIndicatorHeight 这两个技巧确实会摆脱通常的“标签单元”的“框”。）

接下来以显而易见的方式创建三个可绘制对象，tab_selector 和两个不同的点。请参阅上述文章或此页面上的 100 个示例。

魔法密码：

在您的onCreate 中有预期的代码...

viewPager = findViewById(R.id.simple_slide_pager);
tab_layout = findViewById(R.id.tab_layout);
viewPager.setAdapter(new ScreenSlidePagerAdapter(this));

最后是让它工作的神奇代码片段。按照上述方式：

2021 年最新：

TabLayoutMediator tabLayoutMediator =
  new TabLayoutMediator(tab_layout, viewPager, true,
    new TabLayoutMediator.TabConfigurationStrategy() {
      @Override public void onConfigureTab(
        @NonNull TabLayout.Tab tab, int position) { }
    }
);
tabLayoutMediator.attach();

完成了。

（在onConfigureTab 中，你可以做任何声音效果或任何可能需要的东西。对于更短的语法，请参阅上面@F1iX 的关键评论。）

Answer 6

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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="match_parent"
    android:orientation="vertical">

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/vpImage"
        android:layout_width="match_parent"
        android:layout_height="@dimen/_150sdp" />

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tlImage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabBackground="@drawable/selector_product_image"
        app:tabGravity="center"
        app:tabIndicatorHeight="0dp"
        app:tabMaxWidth="12dp"
        app:tabRippleColor="@null" />

</androidx.appcompat.widget.LinearLayoutCompat>

---

ImageAdapter imageAdapter = new ImageAdapter(getActivity(), arrayListSlider);
binding.vpImage.setOffscreenPageLimit(1);
binding.vpImage.setAdapter(imageAdapter);
binding.tlImage.setupWithViewPager(binding.vpImage);

selector_product_image.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">

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

</selector>

image_selected.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape
            android:innerRadius="0dp"
            android:shape="ring"
            android:thickness="4dp"
            android:useLevel="false">
            <solid android:color="@color/colorAccent" />
        </shape>
    </item>
</layer-list>

image_unselected.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape
            android:innerRadius="0dp"
            android:shape="ring"
            android:thickness="4dp"
            android:useLevel="false">
            <solid android:color="@color/colorPrimary" />
        </shape>
    </item>
</layer-list>

ImageAdapter.java

class ImageAdapter extends PagerAdapter {

  private Context context;
  private ArrayList<ImageModel> arrayList;
  private LayoutInflater layoutInflater;

  public ImageAdapter(Context context, ArrayList<ImageModel> arrayList) {
      this.context = context;
      this.arrayList = arrayList;
      this.layoutInflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  }

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

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

  @Override
  public Object instantiateItem(ViewGroup container, int position) {
      View view = layoutInflater.inflate(R.layout.row_slider_image, container, false);

      AppCompatImageView ivProductImage = view.findViewById(R.id.ivProductImage);

      if (!TextUtils.isEmpty(arrayList.get(position).getImage())) {
          Glide.with(context)
                  .load(arrayList.get(position).getImage())
                  .apply(new RequestOptions().placeholder(R.drawable.no_image).error(R.drawable.no_image))
                  .into(ivProductImage);
      }

      container.addView(view);
      return view;
  }

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

row_slider_image.xml

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

    <androidx.appcompat.widget.AppCompatImageView
        android:id="@+id/ivProductImage"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:adjustViewBounds="true"
        android:scaleType="fitXY"
        android:src="@drawable/no_image" />

</androidx.appcompat.widget.LinearLayoutCompat>

Answer 7

你的 xml

  <RelativeLayout
                android:id="@+id/rl_speed"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_above="@+id/ll_dashboard_buttons"
                android:layout_below="@+id/ib_menu">

                <com.smart.gps.speedometer.app.utils.SmartViewPager
                    android:id="@+id/view_pager"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" 
                   app:layout_behavior="@string/appbar_scrolling_view_behavior">
                   </com.smart.gps.speedometer.app.utils.SmartViewPager>

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

创建一个drawable。右键单击drawable - > new - > Drawable文件资源 命名该文件

tab_selector.xml

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

<item android:drawable="@drawable/unselected_tab"/>

现在还有两个 xml 文件。再创建两个具有尊重名称的 xml 文件。这些是选择器指示器和未选择指示器

selected_tab.xml

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

unselected_tab.xml

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

Answer 8

将 ViewFlipper 和 viewFlipper_linear_dot_lay(Linearlayout) 放在同一基线上，然后按照下面的方法进行

viewFlipper_linear_dot_lay= (LinearLayout) findViewById(R.id.dots_lay);
setupDotsOnViewPager(images_viewFlipper);
    for (int i = 0; i < images_viewFlipper.size(); i++) {
    //Add Images to ViewFlipper 
    }



private void setupDotsOnViewPager(ArrayList images_viewFlipper) {
                    images_linear = new ImageView[images_viewFlipper.size()];
                    for (int i = 0; i < images_linear.length; i++) {
                        images_linear[i] = new ImageView(this);
                        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
                        params.setMargins(5, 0, 5, 0);
                        params.gravity = Gravity.BOTTOM | Gravity.CENTER;
                        images_linear[i].setLayoutParams(params);
                        images_linear[i].setImageResource(R.drawable.unselected);
                        viewFlipper_linear_dot_lay.addView(images_linear[i]);
                        viewFlipper_linear_dot_lay.bringToFront();
                    }
                }

OnRight & OnLeft getsures 放置下面的代码

for (int i = 0; i < images_linear.length; i++) {
 images_linear[i].setImageResource(R.drawable.unselected);
 }
images_linear[viewFlipper.getDisplayedChild()].setImageResource(R.drawable.selected);

Answer 9

添加依赖项 > 同步 Gradle

implementation 'com.tbuonomo.andrui:viewpagerdotsindicator:4.1.2'

在你的 java 代码中

 dotsIndicator = (DotsIndicator) findViewById(R.id.dots_indicator3);


myViewPagerAdapter = new MyViewPagerAdapter();
        viewPager.setAdapter(myViewPagerAdapter);
        viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
        dotsIndicator.setViewPager(viewPager);

在你的布局中

<com.tbuonomo.viewpagerdotsindicator.SpringDotsIndicator
android:id="@+id/spring_dots_indicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:dampingRatio="0.5"
app:dotsColor="@color/material_white"
app:dotsStrokeColor="@color/material_yellow"
app:dotsCornerRadius="2dp"
app:dotsSize="16dp"
app:dotsSpacing="6dp"
app:dotsStrokeWidth="2dp"
app:stiffness="300"
/>