[問題] surfaceView如何清空上一次的畫面?

看板AndroidDev作者uzoo (coding....coding)時間13年前 (2011/10/12 21:55)推噓1(1推 0噓 6→)

留言7則, 2人參與討論串1/1

先感謝進來看文章的各位大大!! 這問題小弟已經GOOGLE過大部分都是建議畫一個全畫面的矩形來覆蓋上一次的畫面小弟也有實做看看，不過為什麼沒有效果阿啊啊啊啊啊!! 小弟是每3秒跟系統要一次時間然後用drawText畫在畫面上! 結果畫出來的文字都一直重疊嗚嗚附上完整程式碼: public class SurfaceVewTestActivity extends Activity implements SurfaceHolder.Callback { private SurfaceView sv; private SurfaceHolder svHolder; private String time; private int width,height; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); sv=new SurfaceView(this); WindowManager manager=(WindowManager) getSystemService(WINDOW_SERVICE); Display display=manager.getDefaultDisplay(); width=display.getWidth(); height=display.getHeight(); Log.d("uzoo", "width:"+width+" height:"+height); svHolder=sv.getHolder(); svHolder.addCallback(this); setContentView(sv); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // TODO Auto-generated method stub } @Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub Log.d("uzoo", "ready to draw"); handler.post(r); } @Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub } public void letsGoDrawing(String time){ Paint paint=new Paint(); paint.setColor(Color.RED); paint.setTextSize(25); Canvas vas=svHolder.lockCanvas(); vas.drawText(time, 130, 130, paint); svHolder.unlockCanvasAndPost(vas); } Handler handler=new Handler(); Runnable r=new Runnable() { @Override public void run() { // TODO Auto-generated method stub Canvas vas=svHolder.lockCanvas(); Paint paint=new Paint(); paint.setColor(Color.BLACK); paint.setAntiAlias(true); Rect rec=new Rect(0, 0, width, height); vas.drawRect(rec, paint); svHolder.unlockCanvasAndPost(vas); String time=""+System.currentTimeMillis(); letsGoDrawing(time); handler.postDelayed(r, 3000); } }; } 希望有大大能幫我解答先謝過了! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 175.98.114.58