android RelativeLayout, equal spacing?

I'm using Relative Layout to create a calculator screen, and i have a row of buttons labeled 1, 2, and 3. I want them evenly spaced, but i'm not sure how to do this with Relative Layout

I'm used to using the android:layout_weight function in LinearLayout, and give each of them a value of android:layout_width="fill_parent", as well as a layout_weight="1"

any way to get this to happen on calculator screen (without specifying DP or PX)

this is what i have set up at the moment, and they are aligned in order from left to right, under the TextView (calculator output screen). any suggestions/solutions to evenly space, filling the width of the screen?

    <TextView
android:开发者_JS百科id="@+id/textView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/edit_text"
android:layout_margin="6px"
/>

<Button
android:id="@+id/button1"
android:text="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView"
/>

<Button
android:id="@+id/button2"
android:text="2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView"
android:layout_toRightOf="@+id/button1"/>

<Button
android:id="@+id/button3"
android:text="3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView"
android:layout_toRightOf="@+id/button2"
/>

If you want equal spacing, you do not want a RelativeLayout. Use a LinearLayout, as you suggest in your question. If needed, put the Buttons in a LinearLayout and put the LinearLayout in the RelativeLayout.

The easiest would be to manipulate the view during OnCreate().

Something like:

OnCreate(Context ctx){
  int w = getWidth();
  int h = getHeight();
  Button B1 = findViewById(R.id.button1);
  B1.setWidth(w/3);
  --repeat for button2,3 textview--
}

Another option would be to use a TableLayout where you stretch the columns and force the buttons to fill parent. This would require you to use

<TableLayout    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:stretchColumns="0,1,2"
    android:layout_below="@+id/textView"> 
<TableRow><Button
android:id="@+id/button1"
android:text="1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/><Button
android:id="@+id/button2"
android:text="2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</TableRow>
</TableLayout>