“处理”按钮在“回收视图”中的行内单击

我使用以下代码处理行单击

static class RecyclerTouchListener implements RecyclerView.OnItemTouchListener {


private GestureDetector gestureDetector;
private ClickListener clickListener;


public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener) {
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}


@Override
public void onLongPress(MotionEvent e) {
View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null) {
clickListener.onLongClick(child, recyclerView.getChildPosition(child));
}
}
});
}


@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {


View child = rv.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
clickListener.onClick(child, rv.getChildPosition(child));
}
return false;
}


@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
}

但是，如果我希望在每一行上都有一个删除按钮，那么这种方法是可行的。我不确定如何用这个来实现它。

我附加了 OnClick 侦听器来删除按钮，这个按钮可以工作(删除行) ，但是它也会触发整行的 OnClick。

有人能帮助我在如何避免全行点击，如果一个单一的按钮被点击。

谢谢。

133559 次浏览
小开

You need to return true inside onInterceptTouchEvent() when you handle click event.

小开
最佳答案

this is how I handle multiple onClick events inside a recyclerView:

Edit : Updated to include callbacks (as mentioned in other comments). I have used a WeakReference in the ViewHolder to eliminate a potential memory leak.

Define interface :

public interface ClickListener {


void onPositionClicked(int position);
    

void onLongClicked(int position);
}

Then the Adapter :

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
    

private final ClickListener listener;
private final List<MyItems> itemsList;


public MyAdapter(List<MyItems> itemsList, ClickListener listener) {
this.listener = listener;
this.itemsList = itemsList;
}


@Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.my_row_layout), parent, false), listener);
}


@Override public void onBindViewHolder(MyViewHolder holder, int position) {
// bind layout and data etc..
}


@Override public int getItemCount() {
return itemsList.size();
}


public static class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {


private ImageView iconImageView;
private TextView iconTextView;
private WeakReference<ClickListener> listenerRef;


public MyViewHolder(final View itemView, ClickListener listener) {
super(itemView);


listenerRef = new WeakReference<>(listener);
iconImageView = (ImageView) itemView.findViewById(R.id.myRecyclerImageView);
iconTextView = (TextView) itemView.findViewById(R.id.myRecyclerTextView);


itemView.setOnClickListener(this);
iconTextView.setOnClickListener(this);
iconImageView.setOnLongClickListener(this);
}


// onClick Listener for view
@Override
public void onClick(View v) {


if (v.getId() == iconTextView.getId()) {
Toast.makeText(v.getContext(), "ITEM PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(v.getContext(), "ROW PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show();
}
            

listenerRef.get().onPositionClicked(getAdapterPosition());
}




//onLongClickListener for view
@Override
public boolean onLongClick(View v) {


final AlertDialog.Builder builder = new AlertDialog.Builder(v.getContext());
builder.setTitle("Hello Dialog")
.setMessage("LONG CLICK DIALOG WINDOW FOR ICON " + String.valueOf(getAdapterPosition()))
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {


}
});


builder.create().show();
listenerRef.get().onLongClicked(getAdapterPosition());
return true;
}
}
}

Then in your activity/fragment - whatever you can implement : Clicklistener - or anonymous class if you wish like so :

MyAdapter adapter = new MyAdapter(myItems, new ClickListener() {
@Override public void onPositionClicked(int position) {
// callback performed on click
}


@Override public void onLongClicked(int position) {
// callback performed on click
}
});

To get which item was clicked you match the view id i.e. v.getId() == whateverItem.getId()

Hope this approach helps!

小开

I find that typically:

  • I need to use multiple listeners because I have several buttons.
  • I want my logic to be in the activity and not the adapter or viewholder.

So @mark-keen's answer works well but having an interface provides more flexibility:

public static class MyViewHolder extends RecyclerView.ViewHolder {


public ImageView iconImageView;
public TextView iconTextView;


public MyViewHolder(final View itemView) {
super(itemView);


iconImageView = (ImageView) itemView.findViewById(R.id.myRecyclerImageView);
iconTextView = (TextView) itemView.findViewById(R.id.myRecyclerTextView);


iconTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onClickListener.iconTextViewOnClick(v, getAdapterPosition());
}
});
iconImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onClickListener.iconImageViewOnClick(v, getAdapterPosition());
}
});
}
}

Where onClickListener is defined in your adapter:

public MyAdapterListener onClickListener;


public interface MyAdapterListener {


void iconTextViewOnClick(View v, int position);
void iconImageViewOnClick(View v, int position);
}

And probably set through your constructor:

public MyAdapter(ArrayList<MyListItems> newRows, MyAdapterListener listener) {


rows = newRows;
onClickListener = listener;
}

Then you can handle the events in your Activity or wherever your RecyclerView is being used:

mAdapter = new MyAdapter(mRows, new MyAdapter.MyAdapterListener() {
@Override
public void iconTextViewOnClick(View v, int position) {
Log.d(TAG, "iconTextViewOnClick at position "+position);
}


@Override
public void iconImageViewOnClick(View v, int position) {
Log.d(TAG, "iconImageViewOnClick at position "+position);
}
});
mRecycler.setAdapter(mAdapter);
小开

I wanted a solution that did not create any extra objects (ie listeners) that would have to be garbage collected later, and did not require nesting a view holder inside an adapter class.

In the ViewHolder class

private static class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {


private final TextView ....// declare the fields in your view
private ClickHandler ClickHandler;


public MyHolder(final View itemView) {
super(itemView);
nameField = (TextView) itemView.findViewById(R.id.name);
//find other fields here...
Button myButton = (Button) itemView.findViewById(R.id.my_button);
myButton.setOnClickListener(this);
}
...
@Override
public void onClick(final View view) {
if (clickHandler != null) {
clickHandler.onMyButtonClicked(getAdapterPosition());
}
}

Points to note: the ClickHandler interface is defined, but not initialized here, so there is no assumption in the onClick method that it was ever initialized.

The ClickHandler interface looks like this:

private interface ClickHandler {
void onMyButtonClicked(final int position);
}

In the adapter, set an instance of 'ClickHandler' in the constructor, and override onBindViewHolder, to initialize `clickHandler' on the view holder:

private class MyAdapter extends ...{


private final ClickHandler clickHandler;


public MyAdapter(final ClickHandler clickHandler) {
super(...);
this.clickHandler = clickHandler;
}


@Override
public void onBindViewHolder(final MyViewHolder viewHolder, final int position) {
super.onBindViewHolder(viewHolder, position);
viewHolder.clickHandler = this.clickHandler;
}

Note: I know that viewHolder.clickHandler is potentially getting set multiple times with the exact same value, but this is cheaper than checking for null and branching, and there is no memory cost, just an extra instruction.

Finally, when you create the adapter, you are forced to pass a ClickHandlerinstance to the constructor, as so:

adapter = new MyAdapter(new ClickHandler() {
@Override
public void onMyButtonClicked(final int position) {
final MyModel model = adapter.getItem(position);
//do something with the model where the button was clicked
}
});

Note that adapter is a member variable here, not a local variable

小开

Just wanted to add another solution if you already have a recycler touch listener and want to handle all of the touch events in it rather than dealing with the button touch event separately in the view holder. The key thing this adapted version of the class does is return the button view in the onItemClick() callback when it's tapped, as opposed to the item container. You can then test for the view being a button, and carry out a different action. Note, long tapping on the button is interpreted as a long tap on the whole row still.

public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener
{
public static interface OnItemClickListener
{
public void onItemClick(View view, int position);
public 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)
{
// Important: x and y are translated coordinates here
final ViewGroup childViewGroup = (ViewGroup) recyclerView.findChildViewUnder(e.getX(), e.getY());


if (childViewGroup != null && mListener != null) {
final List<View> viewHierarchy = new ArrayList<View>();
// Important: x and y are raw screen coordinates here
getViewHierarchyUnderChild(childViewGroup, e.getRawX(), e.getRawY(), viewHierarchy);


View touchedView = childViewGroup;
if (viewHierarchy.size() > 0) {
touchedView = viewHierarchy.get(0);
}
mListener.onItemClick(touchedView, recyclerView.getChildPosition(childViewGroup));
return true;
}


return false;
}


@Override
public void onLongPress(MotionEvent e)
{
View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());


if(childView != null && mListener != null)
{
mListener.onItemLongClick(childView, recyclerView.getChildPosition(childView));
}
}
});
}


public void getViewHierarchyUnderChild(ViewGroup root, float x, float y, List<View> viewHierarchy) {
int[] location = new int[2];
final int childCount = root.getChildCount();


for (int i = 0; i < childCount; ++i) {
final View child = root.getChildAt(i);
child.getLocationOnScreen(location);
final int childLeft = location[0], childRight = childLeft + child.getWidth();
final int childTop = location[1], childBottom = childTop + child.getHeight();


if (child.isShown() && x >= childLeft && x <= childRight && y >= childTop && y <= childBottom) {
viewHierarchy.add(0, child);
}
if (child instanceof ViewGroup) {
getViewHierarchyUnderChild((ViewGroup) child, x, y, viewHierarchy);
}
}
}


@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e)
{
mGestureDetector.onTouchEvent(e);


return false;
}


@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent){}


@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {


}
}

Then using it from activity / fragment:

recyclerView.addOnItemTouchListener(createItemClickListener(recyclerView));


public RecyclerItemClickListener createItemClickListener(final RecyclerView recyclerView) {
return new RecyclerItemClickListener (context, recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
if (view instanceof AppCompatButton) {
// ... tapped on the button, so go do something
} else {
// ... tapped on the item container (row), so do something different
}
}


@Override
public void onItemLongClick(View view, int position) {
}
});
}
小开

You can check if you have any similar entries first, if you get a collection with size 0, start a new query to save.

OR

more professional and faster way. create a cloud trigger (before save)

check out this answer https://stackoverflow.com/a/35194514/1388852

小开

Just put an override method named getItemId Get it by right click>generate>override methods>getItemId Put this method in the Adapter class


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