public class MainActivity extends AppCompatActivity {

    private ViewGroup title_bar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        Toast.makeText(this,"MainActivity...",Toast.LENGTH_SHORT).show();

        //當系統版本為4.4或者4.4以上時可以使用沉浸式狀態列
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            //透明狀態列
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            //透明導航欄
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
        }
        setStatusBar();
    }

    /**
     * 設定沉浸式狀態列
     */
    protected void setStatusBar() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            title_bar = (ViewGroup) findViewById(R.id.bar_layout);
            final int statusHeight = getStatusBarHeight();
            title_bar.post(new Runnable() {
                @Override
                public void run() {
                    int titleHeight = title_bar.getHeight();
                    android.widget.RelativeLayout.LayoutParams params = (android.widget.RelativeLayout.LayoutParams) title_bar.getLayoutParams();
                    params.height = statusHeight + titleHeight;
                    title_bar.setLayoutParams(params);
                }
            });
        }
    }
    /**
     * 獲取狀態列的高度
     * @return
     */
    protected int getStatusBarHeight(){
        try
        {
            Class<?> c = Class.forName("com.android.internal.R$dimen");
            Object obj = c.newInstance();
            Field field = c.getField("status_bar_height");
            int x = Integer.parseInt(field.get(obj).toString());
            return  getResources().getDimensionPixelSize(x);
        }catch(Exception e){
            e.printStackTrace();
        }
        return 0;
    }
}