好吧,经过一番研究,我得出的结论是用我的ViewPager2
with a recyclerView
这将“表现得像” viewPager :/ 。
首先我更换了我的viewPager2
与水平的recyclerView
。要使其表现得像viewpager,请使用SnapHelper
.
RecyclerView childRecyclerView2 = findViewById(R.id.previously_viewPager);
// other init like setup layout manager, adapter etc
SnapHelper snapHelper = new PagerSnapHelper();
snapHelper.attachToRecyclerView(replacedRecyclerView); // <-- this makes out rv behave like a viewPager
之后,您必须添加一个OnItemTouchListener
并覆盖onInterceptTouchEvent
就像我问题中的代码段一样:
childRecyclerView2.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
@Override
public boolean onInterceptTouchEvent(@NonNull RecyclerView rv, @NonNull MotionEvent e) {
// same as the code segment in the question,
//so skipping this part.
//just copy it from my question
}
// ...
}
选修的:
在 viewPager2 中,您可以通过以下方式获取当前焦点getCurrentItem()
,但是由于我们已经用recyclerview替换了viewpager2,所以我们没有这个方法。因此,我们需要实现我们自己的等效版本。如果你是 Kotlin 爱好者,你可以直接跳到参考文献2 https://medium.com/over-engineering/detecting-snap-changes-with-androids-recyclerview-snaphelper-9e9f5e95c424并跳过这部分。如果您需要的话,这里是 java 版本,不过我会跳过解释。
创造SnapHelperExt.java
public class SnapHelperExt {
public SnapHelperExt(){}
public int getSnapPosition(RecyclerView recyclerView, SnapHelper snapHelper){
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
View snapView = snapHelper.findSnapView(layoutManager);
if (snapView != null) {
return layoutManager.getPosition(snapView);
}else{
return -1;
}
}
}
接下来创建一个界面OnSnapPositionChangeListener
作为我们的听众:
public interface OnSnapPositionChangeListener {
void onSnapPositionChange(int position);
}
之后,创建SnapOnScrollListener.java
:
public class SnapOnScrollListener extends RecyclerView.OnScrollListener {
public enum Behavior {
NOTIFY_ON_SCROLL,
NOTIFY_ON_SCROLL_STATE_IDLE
}
private SnapHelperExt snapHelperExt;
private SnapHelper snapHelper;
private Behavior behavior;
private OnSnapPositionChangeListener onSnapPositionChangeListener;
private int snapPosition = RecyclerView.NO_POSITION;
public SnapOnScrollListener(SnapHelper snapHelper, Behavior behavior, OnSnapPositionChangeListener onSnapPositionChangeListener){
this.snapHelper = snapHelper;
this.behavior = behavior;
this.onSnapPositionChangeListener = onSnapPositionChangeListener;
this.snapHelperExt = new SnapHelperExt();
}
@Override
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (behavior == Behavior.NOTIFY_ON_SCROLL) {
maybeNotifySnapPositionChange(recyclerView);
}
}
@Override
public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (behavior == Behavior.NOTIFY_ON_SCROLL_STATE_IDLE
&& newState == RecyclerView.SCROLL_STATE_IDLE) {
maybeNotifySnapPositionChange(recyclerView);
}
}
private void maybeNotifySnapPositionChange(RecyclerView recyclerView){
int prevPosition = this.snapHelperExt.getSnapPosition(recyclerView, snapHelper);
boolean snapPositionIsChanged = (this.snapPosition!=prevPosition);
if(snapPositionIsChanged){
onSnapPositionChangeListener.onSnapPositionChange(prevPosition);
this.snapPosition = prevPosition;
}
}
}
最后,这样使用:
SnapOnScrollListener snapOnScrollListener = new SnapOnScrollListener(
snapHelper,
SnapOnScrollListener.Behavior.NOTIFY_ON_SCROLL,
position -> {
Log.e(TAG, "currently focused page no = "+position);
// your code here, do whatever you want
}
);
childRecyclerView2.addOnScrollListener(snapOnScrollListener);
参考:
- 使用recyclerview创建viewpager https://www.linkedin.com/pulse/create-viewpager-using-recyclerview-android-ali-ahmed/
- 使用 androids-recyclerview 检测快照更改 https://medium.com/over-engineering/detecting-snap-changes-with-androids-recyclerview-snaphelper-9e9f5e95c424