ViewPager2 滑动分页视图

1. 修改 App 样式，去掉导航栏

  <application android:theme="@style/Theme.AppCompat.NoActionBar" >

2. 添加矢量图

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="100dp"
    android:height="100dp"
    android:tint="#FFFFFFFF"
    android:viewportWidth="24"
    android:viewportHeight="24">
    <path
        android:fillColor="@android:color/white"
        android:pathData="M16.84,14.52c-0.26,-0.19 -0.62,-0.63 -0.79,-0.84C17.24,12.01 19,8.87 19,5c0,-1.95 -0.74,-3 -2,-3c-1.54,0 -3.96,2.06 -5,5.97C10.96,4.06 8.54,2 7,2C5.74,2 5,3.05 5,5c0,3.87 1.76,7.01 2.95,8.68c-0.17,0.21 -0.53,0.65 -0.79,0.84c-0.5,0.41 -1.66,1.37 -1.66,2.98c0,2.21 1.79,4 4,4c1.55,0 2.5,-0.56 2.5,-0.56s0.95,0.56 2.5,0.56c2.21,0 4,-1.79 4,-4C18.5,15.89 17.34,14.93 16.84,14.52zM9.35,12.2C8.34,10.7 7,8.12 7,5c0,-0.49 0.06,-0.8 0.12,-0.97c0.94,0.31 3.24,2.71 3.38,7.64C10.03,11.79 9.66,11.97 9.35,12.2zM10.5,16.75c-0.28,0 -0.5,-0.34 -0.5,-0.75c0,-0.41 0.22,-0.75 0.5,-0.75S11,15.59 11,16C11,16.41 10.78,16.75 10.5,16.75zM12,19.5c-0.55,0 -1,-0.72 -1,-1c0,-0.28 0.45,-0.5 1,-0.5s1,0.22 1,0.5C13,18.78 12.55,19.5 12,19.5zM13.5,16.75c-0.28,0 -0.5,-0.34 -0.5,-0.75c0,-0.41 0.22,-0.75 0.5,-0.75S14,15.59 14,16C14,16.41 13.78,16.75 13.5,16.75zM13.5,11.67c0.14,-4.93 2.44,-7.33 3.38,-7.64C16.94,4.2 17,4.51 17,5c0,3.12 -1.34,5.7 -2.35,7.2C14.34,11.97 13.97,11.79 13.5,11.67z" />
</vector>

3. 创建三个 Fragment

  3.1 缩放布局，fragment_scale.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".ScaleFragment">

    <ImageView
        android:id="@+id/imageViewScale"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:src="@drawable/ic_baseline_cruelty_free" />
</FrameLayout>

  3.2 缩放 Fragment，ScaleFragment.kt

class ScaleFragment : Fragment() {
    private lateinit var binding: FragmentScaleBinding

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
    ): View? {
        binding = FragmentScaleBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.imageViewScale.setOnClickListener {
            val factor = if (Random.nextBoolean()) 0.1f else -0.1f
            ObjectAnimator.ofFloat(it, "scaleX", it.scaleX + factor).start()
            ObjectAnimator.ofFloat(it, "scaleY", it.scaleY + factor).start()
        }
    }
}

  3.3 旋转布局，fragment_rotate.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".RotateFragment">

    <ImageView
        android:id="@+id/imageViewRotate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:src="@drawable/ic_baseline_cruelty_free" />
</FrameLayout>

  3.4 旋转 Fragment，RotateFragment.kt

class RotateFragment : Fragment() {
    private lateinit var binding: FragmentRotateBinding

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
    ): View? {
        binding = FragmentRotateBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.imageViewRotate.setOnClickListener {
            ObjectAnimator.ofFloat(it,"rotation",it.rotation + 30f).start()
        }
    }
}

  3.5 平移布局，fragment_translate.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".TranslateFragment">

    <ImageView
        android:id="@+id/imageViewTranslate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:src="@drawable/ic_baseline_cruelty_free" />
</FrameLayout>

  3.6 平移 Fragment，TranslateFragment.kt

class TranslateFragment : Fragment() {
    private lateinit var binding: FragmentTranslateBinding

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
    ): View? {
        binding = FragmentTranslateBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.imageViewTranslate.setOnClickListener {
            val factor = if (Random.nextBoolean()) 2f else -2f
            ObjectAnimator.ofFloat(it, "translationX", it.translationX + Random.nextInt(-100, 100)).start()
        }
    }
}

4. 调用主页

  4.1 布局文件 activity_main.xml

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

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tabLayout"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        app:tabIndicatorColor="#FFFFFF">

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Monday" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Tuesday" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Wednesday" />
    </com.google.android.material.tabs.TabLayout>

    <View
        android:id="@+id/divider"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="?android:attr/listDivider" />

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/viewPager2"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </androidx.viewpager2.widget.ViewPager2>
</LinearLayout>

  4.2 主页 MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.viewPager2.adapter = object : FragmentStateAdapter(this) {
            override fun getItemCount() = 3
            override fun createFragment(position: Int) =
                when (position) {
                    0 -> ScaleFragment()
                    1 -> RotateFragment()
                    else -> TranslateFragment()
                }
        }
        
        TabLayoutMediator(binding.tabLayout, binding.viewPager2) { tab, position ->
            when (position) {
                0 -> tab.text = "缩放"
                1 -> tab.text = "旋转"
                else -> tab.text = "移动"
            }
        }.attach()
    }
}

5. 效果图

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