白天黑夜模式转换

public class MainActivity extends Activity{

    private WindowManager wm;

    private View myView;

    private Button button;

    private SharedPreferences sp;

    private final static String DAY = "day";

    private final static String NIGHT = "night";

    private int flage = 0;


    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);

        setContentView(R.layout.activity_main);

        sp = this.getSharedPreferences("skinchange", Context.MODE_PRIVATE);

        button = (Button) findViewById(R.id.btn_dayAndnight);

        String mode = sp.getString("skin", "");

        if(mode!=null||!mode.equals("")){

            if(mode.equals(NIGHT)){

                night();

            }else{

                day();

            }

        }

        button.setOnClickListener(new OnClickListener() {

            
            @Override
            public void onClick(View v) {

        SharedPreferences sp2=getSharedPreferences("aa", MODE_APPEND);
                int flage=sp2.getInt("bb", 0);
                if(flage%2==0){

                    night();

                    button.setText("白天模式");

                    button.setTextColor(Color.WHITE);

                    flage++;

                }else{

                    day();

                    button.setText("夜间模式");

                    button.setTextColor(Color.BLACK);

                    flage++;

                }

        SharedPreferences sp1=getSharedPreferences("aa", MODE_APPEND);
                Editor ed=sp1.edit();
                ed.putInt("bb", flage);
                ed.commit();
    
            }

        });

    }
    
public void night() {

        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT,
                LayoutParams.TYPE_APPLICATION,
                WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE
                        | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);
        params.gravity=Gravity.BOTTOM;
        params.y=10;
        if(myView==null){
            myView=new TextView(this);
            myView.setBackgroundColor(0x80000000);
        }
        wm.addView(myView, params);
        Editor edit = sp.edit();
        edit.putString("skin", NIGHT);
        edit.commit();
    }

    public void day(){
        if(myView!=null){
            wm.removeView(myView);
            Editor edit = sp.edit();
            edit.putString("skin", DAY);
            edit.commit();
        }
    }
}