Recycleview 更新其布局
Recycleview updates its layout
我的问题之前在很多线程中被问过,例如
How do I make RecyclerView update its layout?。
但不幸的是 none 他们解决了我的问题。
我在 android 项目中使用 recycleview。对于每个项目,我都隐藏了复选框,并且我试图在长按时使其对所有项目都可见。我正在尝试调用: adapter.notifyItemChanged() 在这种情况下但没有任何作用。有时它会更新,有时不会,在更新的情况下,它会更新一些项目并留下其他项目。
这是我的代码:
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(this, recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
@Override
public void onItemLongClick(View view, int position) {
CheckBox checkBox = findViewById(R.id.checkBox);
checkBox.setVisibility(View.VISIBLE);
adapter.notifyItemChanged(position);
}
}));
and my listener class is:
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
private OnItemClickListener mListener;
private GestureDetector mGestureDetector;
public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
mListener = listener;
mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
@Override
public void onLongPress(MotionEvent e) {
View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null) {
mListener.onItemLongClick(childView, recyclerView.getChildAdapterPosition(childView));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
View childView = view.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
我已经通过在适配器中添加布尔标志解决了我的问题。然后,在 onBindViewHolder 方法中,我检查这个标志,并根据它显示或隐藏项目的复选框,如下所示:
if(flag){
holder.itemView.findViewById(R.id.checkBox).setVisibility(View.VISIBLE);
}
最后,在长按方法中,我设置了该标志并调用 notifyDataSetChanged 方法来更新 RecycleView 的布局,如下所示:
adapter.flag = true;
adapter.notifyDataSetChanged();
我的问题之前在很多线程中被问过,例如 How do I make RecyclerView update its layout?。 但不幸的是 none 他们解决了我的问题。 我在 android 项目中使用 recycleview。对于每个项目,我都隐藏了复选框,并且我试图在长按时使其对所有项目都可见。我正在尝试调用: adapter.notifyItemChanged() 在这种情况下但没有任何作用。有时它会更新,有时不会,在更新的情况下,它会更新一些项目并留下其他项目。 这是我的代码:
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(this, recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
@Override
public void onItemLongClick(View view, int position) {
CheckBox checkBox = findViewById(R.id.checkBox);
checkBox.setVisibility(View.VISIBLE);
adapter.notifyItemChanged(position);
}
}));
and my listener class is:
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
private OnItemClickListener mListener;
private GestureDetector mGestureDetector;
public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
mListener = listener;
mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
@Override
public void onLongPress(MotionEvent e) {
View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null) {
mListener.onItemLongClick(childView, recyclerView.getChildAdapterPosition(childView));
}
}
});
}
@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
View childView = view.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
}
return false;
}
@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
我已经通过在适配器中添加布尔标志解决了我的问题。然后,在 onBindViewHolder 方法中,我检查这个标志,并根据它显示或隐藏项目的复选框,如下所示:
if(flag){
holder.itemView.findViewById(R.id.checkBox).setVisibility(View.VISIBLE);
}
最后,在长按方法中,我设置了该标志并调用 notifyDataSetChanged 方法来更新 RecycleView 的布局,如下所示:
adapter.flag = true;
adapter.notifyDataSetChanged();