How to add a horizontal 1px line above image view in a relative layout?

Question

How do I add a horizontal 1px white line above image view in a relative layout?

<RelativeLayout
android:id="@+id/widget38"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="108px"
android:layout_y="87px"
>  
<ImageView
android:id="@+id/widget39"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
>  
</ImageView>  
</RelativeLayout>

Solution 1

Just add the following line in your XML where ever you want it.

<View android:background="#ffffff" 
      android:layout_width = "match_parent" 
      android:layout_height="1dp"/>

Edit: Try this:

<RelativeLayout
android:id="@+id/widget38"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="108px"
android:layout_y="87px"
>
<View android:id="@+id/separator" 
 android:background="#ffffff" 
 android:layout_width = "fill_parent"
 android:layout_height="1dip"
 android:layout_centerVertical ="true"
 android:layout_alignParentTop="true"/>
<ImageView
 android:id="@+id/widget39"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_below="@id/separator"
 android:layout_alignParentRight="true"
/>  
</RelativeLayout>

Solution 2

Consider moving the layout for the line into a separate file:

<!-- horizontal_line.xml -->
<?xml version="1.0" encoding="utf-8"?>
<View
    style="@style/HorizontalLine" />

... referencing a custom style definition:

<!-- styles.xml -->
<style name="HorizontalLine">
    <item name="android:layout_width">fill_parent</item>
    <item name="android:layout_height">@dimen/horizontal_line_height</item>
    <item name="android:background">@color/horizontal_line_fill_color</item>
    <item name="android:layout_marginTop">@dimen/large_spacer</item>
    <item name="android:layout_marginBottom">@dimen/large_spacer</item>
</style>

... and then you can include it in your layout:

<RelativeLayout
    android:id="@+id/widget38"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_x="108px"
    android:layout_y="87px" >

    <include
        android:id="@+id/horizontal_line"
        layout="@layout/horizontal_line" />

    <ImageView
        android:id="@+id/widget39"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/horizontal_line"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true" />

</RelativeLayout>

Comments

[dropsOfJupiter]

I added this and it works great, thank you! Except android:layout_above="@id/your_image_view_id" does not work, it constantly gives me an error. So I had to remove this attribute, but the line is hanging somewhere in the middle of the relative layout.

[Jonik]

I like this approach since it reduces duplication and cleans up the layout files (+1). However, I'd skip the <include>, and just use <View style="@style/HorizontalLine" /> directly in the layout XMLs. Simpler and works the same.