how to highlight the selected Item of Recycler View?
You can use a StateListDrawable to achieve the desired effect.
Example
Create a new Drawable resource file in your drawable
directory with the following content:
selector_row.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Color when the row is selected -->
<item android:drawable="@android:color/darker_gray" android:state_pressed="false" android:state_selected="true" />
<!-- Standard background color -->
<item android:drawable="@android:color/white" android:state_selected="false" />
</selector>
Now simply use this StateListDrawable
as the background in the row-layout of your RecyclerView
row_recyclerview.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/selector_row">
<!-- row content -->
</RelativeLayout>
Now as soon as the onClick()
method in your adapter is called you simply need to do the following:
// myBackground is the RelativeLayout root of your row
myBackground.setSelected(true);
The rows' background will have the color (in this case darker_gray) as long as you call myBackground.setSelected(false)
. Of course you should create a SparseBooleanArray for example in order to know which row is selected and which isn't since the rows will be reused when scrolling.
Edit: Remember selected items
The idea behind the SparseBooleanArray is to remember the items which are selected. Following a sample on how to use it:
public class MyImageAdapter extends RecyclerView.Adapter<MyImageAdapter.MyViewHolder> {
private SparseBooleanArray selectedItems;
// Other stuff [...]
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
// Set the selected state of the row depending on the position
holder.myBackground.setSelected(selectedItems.get(position, false));
}
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
@Override
public void onClick(View v) {
// Save the selected positions to the SparseBooleanArray
if (selectedItems.get(getAdapterPosition(), false)) {
selectedItems.delete(getAdapterPosition());
myBackground.setSelected(false);
}
else {
selectedItems.put(getAdapterPosition(), true);
myBackground.setSelected(true);
}
}
}
}
there is no selector in RecyclerView like ListView and GridView but you try below thing it worked for me
create a selector drawable as below
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true">
<shape>
<solid android:color="@color/blue" />
</shape>
</item>
<item android:state_pressed="false">
<shape>
<solid android:color="@android:color/transparent" />
</shape>
</item>
</selector>
then set this drawable as background of your RecyclerView row layout as
android:background="@drawable/selector"