It seems there is a padding between the bottom input section and bottom margin of an edittext by default. I have a linearlayout(horizon) including one edittext and one button. I just can't make them in one single line perfectly, since the padding between the bottom input section and bottom margin make the edittext lower than the button through I set the same height and alignment for them. 

I also tried Relative layout but cannot solve the problem either, here is my layout

```
<RelativeLayout
    android:id="@+id/SearchLinearLayout"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical|center_horizontal"
    android:layout_marginTop="10dp" >

    <EditText
        android:id="@+id/FilterEditText"
        android:layout_width="fill_parent"
        android:layout_height="38dp"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="5dp"
        android:layout_toLeftOf="@+id/SearchButton"
        android:gravity="center_vertical"
        android:hint="@string/search_or_add_a_place"
        android:imeOptions="flagNoExtractUi"
        android:inputType="text|textNoSuggestions"
        android:textSize="15dp" />

    <Button
        android:id="@+id/SearchButton"
        android:layout_width="38dp"
        android:layout_height="38dp"
        android:layout_alignParentRight="true"
        android:background="@drawable/search_btn"
        android:enabled="false"
        android:gravity="center_vertical" />

</RelativeLayout>

```