android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.TYPE_STATUS_BAR, WindowManager.LayoutParams.TYPE_STATUS_BAR);

requestWindowFeature(Window.FEATURE_NO_TITLE);

public void setFullscreen() {
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
}

<activity android:name=".activity.MainActivity" android:screenOrientation="portrait" android:label="@string/titlebar_text"
</actibity> 2）

requestWindowFeature(Window.FEATURE_NO_TITLE);
//設置窗口無標題欄
setContentView(R.layout.main);
//動態設置標題的值，getTitle()的值是該activity的聲明中android:label的值
((TextView) findViewById(R.id.titlebar_text)).setText(getTitle());

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//預先設置允許改變的窗口狀態，需在 setContentView 之前調用，否則設置標題時拋運行時錯誤。
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.custom_title);
//標題區域可設置為 layout ，如此可以有豐富的展現方式
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,
R.layout.custom_title_1);
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/screen"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<TextView android:id="@+id/left_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:text="@string/custom_title_left" />
</RelativeLayout>