想要全部窗口全屏无标题,修改
res\values\styles.xml 可设置主题和样式
<resources>
    <!--
          Base application theme, dependent on API level. This theme is replaced
          by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
      -->
    <style name="AppBaseTheme" parent="android:Theme.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>
    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- 设置无标题-->
        <item name="android:windowNoTitle">true</item>
        <!-- 设置全屏-->
        <item name="android:windowFullscreen">true</item>
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    </style>
</resources>
如果要单个窗口设置用如下2个方法
1. 修改AndroidManifest.xml
        <activity android:name=".Convert" 
                  android:label="@string/app_name" 
                  android:theme="@android:style/Theme.NoTitleBar.Fullscreen" > 
            <intent-filter> 
                <action android:name="android.intent.action.MAIN" /> 
                <category android:name="android.intent.category.LAUNCHER" /> 
            </intent-filter> 
        </activity> 
即加上 android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
2. 在代码中设置
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);