设置无标题&不显示状态栏

注意！写requestWindowFeature时要放在setContentView(R.layout.activity_main);前面

requestWindowFeature(Window.FEATURE_NO_TITLE);

//标题栏显示进度条
requestWindowFeature(Window.FEATURE_PROGRESS);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PRORESS);
setProgressBarVisibility(true);
setProgressBarIndeterminate(true);

在style文件中的style下加入

<item name="android:windowNoTitle">true</item>

不显示标题栏(在AndroidManifest.xml文件中设置)

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

全屏

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

不显示状态栏：

//去掉Activity上面的状态栏

getWindow().setFlags(WindowManager.LayoutParams. FLAG_FULLSCREEN ,
WindowManager.LayoutParams. FLAG_FULLSCREEN);

另一种方法（推荐）:

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