Margin between items in recycler view Android

I made a class to manage this issue. This class set different margins for the items inside the recyclerView: only the first row will have a top margin and only the first column will have left margin.

public class RecyclerViewMargin extends RecyclerView.ItemDecoration {
private final int columns;
private int margin;

/**
 * constructor
 * @param margin desirable margin size in px between the views in the recyclerView
 * @param columns number of columns of the RecyclerView
 */
public RecyclerViewMargin(@IntRange(from=0)int margin ,@IntRange(from=0) int columns ) {
    this.margin = margin;
    this.columns=columns;

}

/**
 * Set different margins for the items inside the recyclerView: no top margin for the first row
 * and no left margin for the first column.
 */
@Override
public void getItemOffsets(Rect outRect, View view,
                           RecyclerView parent, RecyclerView.State state) {

    int position = parent.getChildLayoutPosition(view);
    //set right margin to all
    outRect.right = margin;
    //set bottom margin to all
    outRect.bottom = margin;
    //we only add top margin to the first row
    if (position <columns) {
        outRect.top = margin;
    }
    //add left margin only to the first column
    if(position%columns==0){
        outRect.left = margin;
        }
    }
}

you can set it in your recyclerview this way

 RecyclerViewMargin decoration = new RecyclerViewMargin(itemMargin, numColumns);
 recyclerView.addItemDecoration(decoration);

1. Find the attribute card_view:cardUseCompatPadding="true" in cards_layout.xml and delete it. Start app and you will find there is no margin between each cardview item.

2. Add margin attributes you like. Ex:

   android:layout_marginTop="5dp"
   android:layout_marginBottom="5dp" 
   

I faced similar issue, with RelativeLayout as the root element for each row in the recyclerview.

To solve the issue, find the xml file that holds each row and make sure that the root element's height is wrap_content NOT match_parent.