Question

I have read many documentation on supporting multiple screen sizes but still confused.
I have read like if specified in dp it will get automatically scaled.

In my sample i just have a single layout. there i have placed an edit text.
and given width , suppose 170 dp. suppose width wise it is half the screen in a 5 inch phone emulator.

What i was expecting is, if i show it on an tablet 7inch or 10 inch , there also it will be half the width of the screen (i.e it will get automatically scaled). But it didnt. in a 10 inch tablet it is only very small size.

what should i do to achieve this only through layout xml ( only single xml )

Answer 1

Learn to use layout weights, you can use them like a percentage of 100.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <TextView
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="50"
        android:text="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" />

    <View
        android:layout_width="0dip"
        android:layout_height="0dip"
        android:layout_weight="50" />

</LinearLayout>

Here the textview takes up 50% of the screen width and the other view is a kind of invisible spacer taking up the other 50% of the screen width.

Which looks something like this (Eclipse XML preview):

As you can see the textview wraps when it gets to 50% of the screen. Working on all sizes of screen.