The layout_weight
property does not appear in the properties palette, my android version is 2.2.3
Is this property no longer supported to place the weight on the layout?
It still exists ... I recommend changing the option from DESIGN to TEXT (you will avoid problems like that)
Then enter the property manually
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1">
<TextView
android:text="ejemplo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>