在Android中正确实现ViewPager2 [英] Proper implementation of ViewPager2 in Android

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本文介绍了在Android中正确实现ViewPager2的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我开始了解 ViewPager2 ，并尝试了来实现它，但是没有找到合适的例子.

I came to know about ViewPager2 and tried to implement it, but didn't find any proper example.

任何人都可以告诉我如何使用它.

Can anyone tell me how can I use it.

我正在寻找正确的用法，而不是示例.

I am looking for proper usage, not an example.

推荐答案

UPDATE 7

检查:从ViewPager迁移到ViewPager2

检查:使用ViewPager2使用标签创建滑动视图

如果要使用View Pager2实现Carousel，请查看我的回答

Check out my answer if you want to implement Carousel using View Pager2

如何在ViewPager2中使用TabLayout

How to use TabLayout with ViewPager2

示例代码

在 dependencies

Use below dependencies

implementation 'com.google.android.material:material:1.1.0-alpha08'
implementation 'androidx.viewpager2:viewpager2:1.0.0-beta02'

示例代码

XMl布局

XMl layout

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <com.google.android.material.appbar.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <androidx.appcompat.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:layout_scrollFlags="scroll|enterAlways"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

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

    <androidx.viewpager2.widget.ViewPager2
            android:id="@+id/viewpager"
            app:layout_anchor="@id/tabs"
            app:layout_anchorGravity="bottom"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
    />


</androidx.coordinatorlayout.widget.CoordinatorLayout>

活动

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*
import com.google.android.material.tabs.TabLayoutMediator

import com.google.android.material.tabs.TabLayout


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

//        setSupportActionBar(toolbar)
        viewpager.adapter = AppViewPagerAdapter(supportFragmentManager, lifecycle)

        TabLayoutMediator(tabs, viewpager, object : TabLayoutMediator.OnConfigureTabCallback {
            override fun onConfigureTab(tab: TabLayout.Tab, position: Int) {
                // Styling each tab here
                tab.text = "Tab $position"
            }
        }).attach()


    }
}

输出

带有ViewPager2的Tab布局

来自文档

ViewPager2

新功能

  • 从右到左(RTL)布局支持
  • 垂直方向支持
  • notifyDataSetChanged完全可用

    • API更改

    API changes

    • FragmentStateAdapter替换FragmentStatePagerAdapter
    • RecyclerView.Adapter替换PagerAdapter
    • registerOnPageChangeCallback替换addPageChangeListener

      • FragmentStateAdapter replaces FragmentStatePagerAdapter
      • RecyclerView.Adapter replaces PagerAdapter
      • registerOnPageChangeCallback replaces addPageChangeListener

        • 示例代码

        为ViewPager2 

        implementation 'androidx.viewpager2:viewpager2:1.0.0-alpha01'

        布局

        <?xml version="1.0" encoding="utf-8"?>
<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:orientation="vertical"
    tools:context=".MainActivity">

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

</LinearLayout>

        活动

        import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;

import java.util.ArrayList;

public class MyActivity extends AppCompatActivity {

    ViewPager2 myViewPager2;
    MyAdapter MyAdapter;
    private ArrayList<String> arrayList = new ArrayList<>();

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

        myViewPager2 = findViewById(R.id.view_pager);

        arrayList.add("Item 1");
        arrayList.add("Item 2");
        arrayList.add("Item 3");
        arrayList.add("Item 4");
        arrayList.add("Item 5");

        MyAdapter = new MyAdapter(this, arrayList);


        myViewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);

        myViewPager2.setAdapter(MyAdapter);
    }
}

        MyAdapter

        MyAdapter

        import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

    private Context context;
    private ArrayList<String> arrayList = new ArrayList<>();

    public MyAdapter(Context context, ArrayList<String> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
        holder.tvName.setText(arrayList.get(position));
    }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tvName;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            tvName = itemView.findViewById(R.id.tvName);
        }
    }
}

        新功能

        现在我们需要使用 ViewPager2.OnPageChangeCallback() 来获取ViewPager2

        示例代码 

            myViewPager2.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            super.onPageScrolled(position, positionOffset, positionOffsetPixels);
        }

        @Override
        public void onPageSelected(int position) {
            super.onPageSelected(position);

            Log.e("Selected_Page", String.valueOf(position));
        }

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

        我们可以使用myViewPager2.setOrientation()

        示例代码

        对于HORIZONTAL Orientation使用

        myViewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);

        对于VERTICAL Orientation使用

        myViewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);

        我们可以使用 notifyDataSetChanged ，与在RecyclerView.Adapter

        示例代码以添加新项目 

            btnAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            arrayList.add("New ITEM ADDED");
            MyAdapter.notifyDataSetChanged();
        }
    });

        示例代码以删除新项目 

            btnRemove.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            arrayList.remove(3);
            MyAdapter.notifyItemRemoved(3);
        }
    });

        更新

        如果要将Fragment与ViewPager2一起使用

        ，请尝试此操作

        UPDATE

        Try this if you want to use Fragment with ViewPager2

        首先创建一个 ViewPagerFragmentAdapter 类，该类扩展了 FragmentStateAdapter

        First create a ViewPagerFragmentAdapter class which extends FragmentStateAdapter

        import java.util.ArrayList;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.viewpager2.adapter.FragmentStateAdapter;

public class ViewPagerFragmentAdapter extends FragmentStateAdapter {

    private ArrayList<Fragment> arrayList = new ArrayList<>();

    public ViewPagerFragmentAdapter(@NonNull FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @NonNull
    @Override
    public Fragment getItem(int position) {
        return arrayList.get(position);
    }

    public void addFragment(Fragment fragment) {
        arrayList.add(fragment);
    }

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

        现在在您的活动中使用

        Now use like this in your activity 

        import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;
import neel.com.bottomappbar.R;

public class MainActivity extends AppCompatActivity {

    ViewPager2 myViewPager2;
    ViewPagerFragmentAdapter myAdapter;

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

        myViewPager2 = findViewById(R.id.view_pager);

        myAdapter = new ViewPagerFragmentAdapter(getSupportFragmentManager());

        // add Fragments in your ViewPagerFragmentAdapter class
        myAdapter.addFragment(new FragmentOne());
        myAdapter.addFragment(new Fragmenttwo());
        myAdapter.addFragment(new FragmentThree());

        // set Orientation in your ViewPager2
        myViewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);

        myViewPager2.setAdapter(myAdapter);

    }

}

        有关更多信息，请检查此

        for more information check this

        • ViewPager2
        • ViewPager2 under the Hood
        • Hands on With ViewPager2

        版本1.0.0-alpha02

        新功能

        • 能够禁用用户输入(setUserInputEnabled，isUserInputEnabled)

        API更改

        • ViewPager2最终班级
        • ViewPager2 class final

        错误修复

        • FragmentStateAdapter稳定性修复程序
        • FragmentStateAdapter stability fixes

        示例代码以禁止在viewpager2中滑动 

        myViewPager2.setUserInputEnabled(false);// SAMPLE CODE to disable swiping in viewpager2


myViewPager2.setUserInputEnabled(true);//SAMPLE CODE to enable swiping in viewpager2

        更新3

        版本1.0.0-alpha03

        Version 1.0.0-alpha03

        新功能

        • 以编程方式滚动ViewPager2的能力: fakeDragBy(offsetPx).

          • Ability to programmatically scroll ViewPager2: fakeDragBy(offsetPx).

            • API更改

            API changes

            • FragmentStateAdapter现在需要一个Lifecycle对象.添加了两个实用程序构造函数，以从主机FragmentActivity或主机Fragment
              • 获取它

              • FragmentStateAdapter now requires a Lifecycle object. Two utility constructors added to obtain it from the host FragmentActivity or the host Fragment

                • 示例代码

                ViewPagerFragmentAdapter

                ViewPagerFragmentAdapter

                import java.util.ArrayList;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.lifecycle.Lifecycle;
import androidx.viewpager2.adapter.FragmentStateAdapter;

public class ViewPagerFragmentAdapter extends FragmentStateAdapter {

    private ArrayList<Fragment> arrayList = new ArrayList<>();


    public ViewPagerFragmentAdapter(@NonNull FragmentManager fragmentManager, @NonNull Lifecycle lifecycle) {
        super(fragmentManager, lifecycle);
    }

    @NonNull
    @Override
    public Fragment getItem(int position) {
        return arrayList.get(position);
    }

    public void addFragment(Fragment fragment) {
        arrayList.add(fragment);
    }

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

                MainActivity代码

                MainActivity code

                import android.os.Bundle;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;
import neel.com.bottomappbar.R;

public class MainActivity extends AppCompatActivity {

    ViewPager2 myViewPager2;
    ViewPagerFragmentAdapter myAdapter;

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

        myViewPager2=findViewById(R.id.view_pager);
        myAdapter = new ViewPagerFragmentAdapter(getSupportFragmentManager(), getLifecycle());

        // add Fragments in your ViewPagerFragmentAdapter class
        myAdapter.addFragment(new FragmentOne());
        myAdapter.addFragment(new Fragmenttwo());
        myAdapter.addFragment(new FragmentThree());

        myViewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);

        myViewPager2.setAdapter(myAdapter);
    }
}

                更新4

                Version 1.0.0-alpha05 新功能

                • ItemDecorator的行为与RecyclerView一致.
                  • 引入了
                • MarginPageTransformer以便提供在页面之间(页面插图之外)创建空间的功能.
                  • 引入了
                • CompositePageTransformer以提供组合多个PageTransformers
                  • 的功能

                  • ItemDecorator introduced with a behaviour consistent with RecyclerView.
                  • MarginPageTransformer introduced to provide an ability to create space between pages (outside of page inset).
                  • CompositePageTransformer introduced to provide an ability to combine multiple PageTransformers

                    • API更改

                    API changes

                    • FragmentStateAdapter#getItem方法重命名为FragmentStateAdapter#createFragment-以前的方法名称被证明是过去漏洞的来源.
                    • OFFSCREEN_PAGE_LIMIT_DEFAULT值从0更改为-1.如果使用OFFSCREEN_PAGE_LIMIT_DEFAULTconstant，则无需更改客户端代码.

                      • FragmentStateAdapter#getItem method renamed to FragmentStateAdapter#createFragment - previous method name has proven to be a source of bugs in the past.
                      • OFFSCREEN_PAGE_LIMIT_DEFAULT value changed from 0 to -1. No need for a client code change if the OFFSCREEN_PAGE_LIMIT_DEFAULTconstant used.

                        • 示例代码

                        活动代码

                        import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager2.widget.MarginPageTransformer;
import androidx.viewpager2.widget.ViewPager2;
import neel.com.bottomappbar.R;

public class MainActivity extends AppCompatActivity {

    ViewPager2 myViewPager2;
    ViewPagerFragmentAdapter myAdapter;
    private ArrayList<Fragment> arrayList = new ArrayList<>();

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

        myViewPager2 = findViewById(R.id.myViewPager2);

        // add Fragments in your ViewPagerFragmentAdapter class
        arrayList.add(new FragmentOne());
        arrayList.add(new Fragmenttwo());
        arrayList.add(new FragmentThree());

        myAdapter = new ViewPagerFragmentAdapter(getSupportFragmentManager(), getLifecycle());
        // set Orientation in your ViewPager2
        myViewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);

        myViewPager2.setAdapter(myAdapter);

        myViewPager2.setPageTransformer(new MarginPageTransformer(1500));


    }
}

                        ViewPagerFragmentAdapter

                        ViewPagerFragmentAdapter

                        import java.util.ArrayList;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.lifecycle.Lifecycle;
import androidx.viewpager2.adapter.FragmentStateAdapter;

public class ViewPagerFragmentAdapter extends FragmentStateAdapter {

    private ArrayList<Fragment> arrayList = new ArrayList<>();


    public ViewPagerFragmentAdapter(@NonNull FragmentManager fragmentManager, @NonNull Lifecycle lifecycle) {
        super(fragmentManager, lifecycle);
    }

    @NonNull
    @Override
    public Fragment createFragment(int position) {
        switch (position) {
            case 0:
                return new FragmentOne();
            case 1:
                return new Fragmenttwo();
            case 2:
                return new FragmentThree();

        }
        return null;
    }

    @Override
    public int getItemCount() {
        return 3;
    }
}

                        这篇关于在Android中正确实现ViewPager2的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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