RecyclerView 实现类似分页滚动的效果

PagerSnapHelper 是 Android 中 RecyclerView 的一个辅助类，用于实现类似于分页滚动的效果。它可以自动将 RecyclerView 的滚动位置“对齐”到最近的页面边界，从而实现类似 ViewPager 的效果。
 

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.PagerSnapHelper;
import androidx.recyclerview.widget.RecyclerView;

public class MainActivity extends AppCompatActivity {

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

        RecyclerView recyclerView = findViewById(R.id.recycler_view);

        // 设置 LayoutManager
        LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

        // 创建并设置适配器
        MyAdapter adapter = new MyAdapter();
        recyclerView.setAdapter(adapter);

        // 创建并附加 PagerSnapHelper
        PagerSnapHelper snapHelper = new PagerSnapHelper();
        snapHelper.attachToRecyclerView(recyclerView);
    }
}

2. 让当前显示的item的View扩大或缩放显示

创建下面的文件

class ScaleCenterItemDecoration(private val scaleFactor: Float = 1f) :
    RecyclerView.ItemDecoration() {

    override fun onDraw(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
        val centerX = parent.width / 2
        for (i in 0 until parent.childCount) {
            val child = parent.getChildAt(i)
            val childCenterX = (child.left + child.right) / 2
            val distanceToCenter = abs(centerX - childCenterX)
            val scale = 1 - (distanceToCenter.toFloat() / centerX) * (1.2f - scaleFactor)

            child.scaleX = scale
            child.scaleY = scale
        }
    }
}

使用

recyclerView.addItemDecoration(ScaleCenterItemDecoration())