
The default theme for tab views in Android 4.0 (the Holo theme) has android:textAllCaps
set to true. You can create your own theme and then apply it to the action bar in your manifest to override this behavior. For more information on styling the ActionBar and creating your own styles, see:
http://developer.android.com/guide/topics/ui/themes.html and http://android-developers.blogspot.com/2011/04/customizing-action-bar.html
YuseonHan
Theres no need to create custom theme
In source code..
TextView tv = (TextView) mTabHost.getTabWidget().getChildAt(index).findViewById(android.R.id.title);
tv.setAllCaps(false);
来源:https://stackoverflow.com/questions/9953240/tab-widget-have-always-in-capital-alphabets-in-android-4-0