Right Align button in horizontal LinearLayout

Single LinearLayout solution. Only adding a simple spacing view:
(No-one seemed to have mentioned this one, only more complicated multi-layout solutions.)

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_marginTop="35dp">

    <TextView
        android:id="@+id/lblExpenseCancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/cancel"
        android:textColor="#404040"
        android:layout_marginLeft="10dp"
        android:textSize="20sp"
        android:layout_marginTop="9dp" />

    <!-------------------------  ADDED SPACER VIEW -------------------->
    <View
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_weight="1"
        />
    <!------------------------- /ADDED SPACER VIEW -------------------->

    <Button
        android:id="@+id/btnAddExpense"
        android:layout_width="wrap_content"
        android:layout_height="45dp"
        android:background="@drawable/stitch_button"
        android:layout_marginLeft="10dp"
        android:text="@string/add"
        android:layout_gravity="right"
        android:layout_marginRight="15dp" />

</LinearLayout>

Note the "highlighted" View, I didn't modify anything else. Height=0 makes sure it's not visible. Width=0 is because the width is determined by the LinearLayout based on weight=1. This means that the spacer view will stretch as much as possible in the direction (orientation) of the LinearLayout.

Note that you should use android.widget.Space or android.support.v4.widget.Space instead of View if your API level and/or dependencies allow it. Space achieves the job in a cheaper way, because it only measures and doesn't try to draw anything like View does; it's also more expressive conveying the intention.

Real solution for it case:

android:layout_weight="1" for TextView, and your button move to right!

I know this question was asked awhile ago, but I have done this before and it allows for more control when aligning items.If you look at it like web programming, it helps. You just nest another LinearLayout that will contain your button inside of it. You can then change the gravity of the button's layout and make it go to the right while the TextView is still on the left.

Try this code:

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"             
android:orientation="horizontal" 
android:layout_marginTop="35dp">

<TextView
    android:id="@+id/lblExpenseCancel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/cancel" 
    android:textColor="#404040"         
    android:layout_marginLeft="10dp" 
    android:textSize="20sp" 
    android:layout_marginTop="9dp"/>

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="right"
    android:orientation="horizontal" >

    <Button
        android:id="@+id/btnAddExpense"
        android:layout_width="wrap_content"
        android:layout_height="45dp"
        android:background="@drawable/stitch_button"
        android:layout_marginLeft="10dp"                    
        android:text="@string/add" 
        android:layout_gravity="right" 
        android:layout_marginRight="15dp"/>

</LinearLayout>

You may have to play with the padding on the nested layout so that it acts how you want it.

Use below code for that

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="35dp"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/lblExpenseCancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="9dp"
        android:text="@string/cancel"
        android:textColor="#404040"
        android:textSize="20sp" />

    <Button
        android:id="@+id/btnAddExpense"
        android:layout_width="wrap_content"
        android:layout_height="45dp"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="15dp"
        android:background="@drawable/stitch_button"
        android:text="@string/add" />

</RelativeLayout>