Change native font size

You can set the font size beyond the android:textAppearance property, using this, android:textSize

Example:

<TextView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:textSize="50sp"/>

You'd better put your code here to see possible errors in your code.

But do the following test, in your main style put the item TextSize

<style name="AppTheme" parent="AppBaseTheme">
    <item name="android:textSize">@style/TextSize</item>
</style>

Create the TextSize style defined above

<style name="TextSize">
   <item name="android:textSize">20sp</item>
</style>

Now there in your AndroidManifest.xml tag in the application tag you check if it has the theme defined:

<application
    android:theme="@style/AppTheme" >
</application>

You can not change a default font size , however you can set a theme and where you can change the font size. To learn more, you can read about Styles and Themes in the Android developer reference documentation.

Example setting theme:

<style name="MyTheme" parent="AppBaseTheme">
    <item name="android:textSize">18sp</item>
</style>

In this way, you will set a default size for all TextView within your application. To define a specific size individually, you can do this:

<TextView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Trump eh o novo presidente dos EUA"
   android:textSize="40sp"/>

Always try to use SP because it is sized independently of the normal font size of the device.

Details

• Multiple Screen Compatibility