android gridview row dividers / separators

Is there a way to show (horizontal) dividers between rows in a gridview?

I tried putting a small divider-image below every grid item, but this is not a solution, because it won't span the whole row when a row is not completely filled with items.

Is there a way to just add an image between every row? I can only find methods for changing the space between rows.

If you are using custom layout for grid items. Below code will work.

Step 1: Give background color to GridView

This is going to serve as a divider.
Give horizontalSpacing and verticalSpacing as 1dp
backgroundColor will be your divider color.

<GridView
        android:id="@+id/gridView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#e5e5e5"
        android:horizontalSpacing="1dp"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:verticalSpacing="1dp" >

Step 2: Give background color to Custom Grid Item Layout

This is going to serve as a foreground color for GridItems.
In my case I kept it white (#fff)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    android:background="#fff"
    android:padding="15dp"
     >

    <ImageView
        android:id="@+id/icon"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:src="@drawable/ic_launcher_transparent" />

    <TextView
        android:id="@+id/lable"
        android:layout_marginTop="5dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Medium Text"
        android:textStyle="bold"
        android:textColor="#D0583B"
        android:textAppearance="?android:attr/textAppearanceSmall" />

</LinearLayout>

Result

Note:
If you do not want vertical separator, keep horizontalSpacing = 0dp
If you do not want horizontal separator, keep verticalSpacing = 0dp

I ended up creating a custom gridview, something like this:

https://stackoverflow.com/a/9757501/1310343

using a background image that is exactly as high as one item in my gridview, and has a devider at the bottom.

Works like a charm!

Just wanted to share how I implemented this using the link accepted by OP. For my case I also needed to control the length of the separators, so I couldn't get around subclassing GridView.

public class HorizontalSeparatorGridView extends GridView {

    // Additional methods 

    @Override
    protected void dispatchDraw(Canvas canvas) {

        final int count = getChildCount();
        for(int i = 0; i < count; i++) {
            View child = getChildAt(i);
            int bottom = child.getBottom();
            int left = child.getLeft();
            int right = child.getRight();

            Paint paint = new Paint();
            paint.setColor(0xffececec);

            paint.setStrokeWidth(Math.round(0.5 * density));

            int offset = // Some offset

            canvas.drawLine(left + offset, bottom, right - offset, bottom, paint);
        }


        super.dispatchDraw(canvas);
    }

I subclassed dispatchDraw as opposed to onDraw just to be safe but I don't think it would matter in this case.