Android button layout adapting to screen size

Question

I am new in Android development.I created a simple project with a simple button.I thought that the button will look the same on different screen sizes but when i previewed all screens eclipse displayed this http://imgur.com/kjEMhHx

This is the xml code

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context="com.example.businessideas.MainActivity" >

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="116dp"
    android:text="Button" />

</RelativeLayout>

Can you please help me and tell me how can i design that button look the same on all screen sizes? Thanks

Answer 1

On the button part change:

android:layout_width="20dp"
android:layout_height="20dp"

Use specific DP sizes to keep items the same physical size on different screen (replace 20 with your desired size).

Answer 2

You'll need to use the weight attribute when the button's parent is LinearLayout. That way it will force the button to have a size proportional to the screens width:

<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:weightSum="10"
    android:orientation="horizontal">
    <Button
        android:id="@+id/button1"
        android:layout_height="wrap_content"
        android:layout_marginTop="116dp"
        android:text="Button"
        android:layout_weight="2"
        android:layout_width="0dp"/>
</LinearLayout>

Notice that if the LinearLayout 's orientation is horizontal, width will be adjusted by android (implicitly) therefore the children have width of 0dp .

Also note that now the button will take 20% (2/10) of the LinearLayout's (the parent's) width.

Answer 3

If you want your button to be of the same size in all different screen than you have to manually give the DP size.

like

andoird:layout_width = "20dp"
android:layout_height = "20dp"

You can also place your button at specific location by changing your relative layout to linear layout.