Android：requestWindowFeature应用程序窗体显示状态操作
注意requestWindowFeature必须在 setContentView()之前调用。
1.DEFAULT_FEATURES：系统默认状态，一般不需要指定
2.FEATURE_CONTEXT_MENU：启用ContextMenu，默认该项已启用，一般无需指定
3.FEATURE_CUSTOM_TITLE：自定义标题。当需要自定义标题时必须指定。如：标题是一个按钮时
4.FEATURE_INDETERMINATE_PROGRESS：不确定的进度
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); setContentView(R.layout.test); setProgressBarIndeterminateVisibility(true);
5.FEATURE_LEFT_ICON：标题栏左侧的图标
requestWindowFeature(Window.FEATURE_LEFT_ICON);
setContentView(R.layout.test);
setFeatureDrawableResource(Window.FEATURE_LEFT_ICON,R.drawable.ic_launcher);
6.FEATURE_NO_TITLE：无标题
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.test);
7.FEATURE_OPTIONS_PANEL：启用“选项面板”功能，默认已启用。
8.FEATURE_PROGRESS：进度指示器功能
9.FEATURE_RIGHT_ICON:设置标题栏右侧图标
requestWindowFeature(Window.FEATURE_RIGHT_ICON);
setContentView(R.layout.test);
setFeatureDrawableResource(Window.FEATURE_RIGHT_ICON,R.drawable.ic_launcher);