在实际开发尤其是电商项目的开发过程中,经常会用到分类的横向滑动列表,但是如果用普通的横向列表在点击的过程无法直接展示,这里我们就需要做到点击每一个item去联动滑动显示在可视化的界面中,直接上效果
import android.content.Context;
import android.util.DisplayMetrics;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.LinearSmoothScroller;
import androidx.recyclerview.widget.RecyclerView;
/**
* Create by Carson on 2021/8/18.
* 自定义recyclerView点击item滑动居中
*/
public class CenterLayoutManager extends LinearLayoutManager {
static int lastPosition = 0;
static int targetPosition = 0;
public CenterLayoutManager(Context context, int orientation, boolean reverseLayout) {
super(context, orientation, reverseLayout);
}
@Override
public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
CenterSmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
smoothScroller.setTargetPosition(position);
startSmoothScroll(smoothScroller);
}
public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int lastPosition, int position) {
CenterLayoutManager.lastPosition = lastPosition;
CenterLayoutManager.targetPosition = position;
smoothScrollToPosition(recyclerView, state, position);
}
public static class CenterSmoothScroller extends LinearSmoothScroller {
private static float duration = 400f;
public CenterSmoothScroller(Context context) {
super(context);
}
@Override
public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference) {
return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2);
}
@Override
protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
float newDuration = duration / (Math.abs(targetPosition - lastPosition));
return newDuration / displayMetrics.densityDpi;
}
@Override
protected int calculateTimeForScrolling(int dx) {
return super.calculateTimeForScrolling(dx);
}
}
}
接下来就是在adapter中进行引用了
CenterLayoutManager centerLayoutManager =
new CenterLayoutManager(mContext, LinearLayoutManager.HORIZONTAL, false);
binding.recyclerTabSort.setLayoutManager(centerLayoutManager);
//这里省略adapter布局的方法
...
...
...
tabSortAdapter.setOnItemClickListener((adapter, view, position) -> {
centerLayoutManager.smoothScrollToPosition(binding.recyclerTabSort,
new RecyclerView.State(), indexPosition, position);
if (indexPosition != position) {
indexPosition = position;
}
tabSortAdapter.notifyDataSetChanged();
});