网上找了一些跑马灯实现都是直接重写的textview不停的改变绘制文字的位置来达到跑马灯效果,但是有的时候需求要求来回滚动多条信息,用textview实现的就不尽人意了,于是用recyclerview整理了一个
思路就是利用recyclerview的scrollBy不停的滚动,来达到效果
recyclerview代码
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import androidx.annotation.Nullable;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.cy.utils.LogUtil;
import java.lang.ref.WeakReference;
public class AutoPollRecyclerView extends RecyclerView {
private static final long TIME_AUTO_POLL = 10;
AutoPollTask autoPollTask;
private boolean running; //标示是否正在自动轮询
private boolean canRun;//标示是否可以自动轮询,可在不需要的是否置false
public AutoPollRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
autoPollTask = new AutoPollTask(this);
}
static class AutoPollTask implements Runnable {
private final WeakReference<AutoPollRecyclerView> mReference;
//使用弱引用持有外部类引用->防止内存泄漏
public AutoPollTask(AutoPollRecyclerView reference) {
this.mReference = new WeakReference<AutoPollRecyclerView>(reference);
}
@Override
public void run() {
AutoPollRecyclerView recyclerView = mReference.get();
if (recyclerView != null && recyclerView.running && recyclerView.canRun) {
LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
if (lastVisibleItemPosition == (Integer.MAX_VALUE - 1))//如果真有人等到一直滚动到最大值那就让他回到头部重新滚
recyclerView.scrollToPosition(0);
recyclerView.scrollBy(2, 2);
recyclerView.postDelayed(recyclerView.autoPollTask, recyclerView.TIME_AUTO_POLL);
}
}
}
//开启:如果正在运行,先停止->再开启
public void start() {
if (running)
stop();
canRun = true;
running = true;
postDelayed(autoPollTask, TIME_AUTO_POLL);
}
public void stop() {
running = false;
removeCallbacks(autoPollTask);
}
@Override
public boolean onTouchEvent(MotionEvent e) {
//若果需要触摸停止就把这里打开
// switch (e.getAction()) {
// case MotionEvent.ACTION_DOWN:
// if (running)
// stop();
// break;
// case MotionEvent.ACTION_UP:
// case MotionEvent.ACTION_CANCEL:
// case MotionEvent.ACTION_OUTSIDE:
// if (canRun)
// start();
// break;
// }
return false;
}
}
其中要注意recyclerview的adapter里面的getItemCount方法要写成最大值,
@Override
public void onBindViewHolder(BaseViewHolder holder, int position) {
String data = mData.get(position % mData.size());
holder.setText(R.id.tv_txt, data);
}
@Override
public int getItemCount() {
return Integer.MAX_VALUE;
}