隱藏

方法1

        //隱藏標題欄
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        //隱藏狀態列
        //定義全屏引數
        int flag=WindowManager.LayoutParams.FLAG_FULLSCREEN;
        //獲得當前窗體物件
        Window window=MainActivity.this.getWindow();
        //設定當前窗體為全屏顯示
        window.setFlags(flag, flag);

注意： 設定去標題與設定全屏引數時候一定要在 setContentView(R.layout.activity_main);

之前

方法2

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

透明

 if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = activity.getWindow();
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS
                    | WindowManager.LayoutParams
 
.FLAG_TRANSLUCENT_NAVIGATION);
            window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            window.addFlags(WindowManager.LayoutParams
 
.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
            window.setNavigationBarColor(Color.TRANSPARENT);
        }