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我試圖學習Android圖形&事件handeling爲多人遊戲。Android，無法在模擬器上繪製基於Touch或MotionEvent的視圖
的構建塊林開發一些代碼，將利用基於觸摸/移動事件點的路徑，但林無法得出，沒有東西畫在模擬器
我有3個簡單的類（MyPoint，GameCanvas類，遊戲）：
1）MyPoint類封裝X & y位置，得出方法繪製基於這些位置的點
public class MyPoint {
private float x;
private float y;
Paint pWhite = new Paint(R.color.white);
public MyPoint(float x, float y) {
this.x = x;
this.y = y;
}//end const
public void draw(Canvas canvas) {
canvas.drawPoint(this.x, this.y, pWhite);
}//end method
}//end MyPoint Class
2）的GameCanvas是將要繪製在視圖中，這類負責對於 其對事件通過實施OnTouchListener處理，onThouch（）方法
public class GameCanvas extends View implements OnTouchListener {
//keep track on points created by touch events
java.util.List<MyPoint> pointsList = null;
public GameCanvas(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
setOnTouchListener(this);
pointsList = new java.util.Stack();
}//end const
//onDraw iterates through points that were added during motion/touch events and calls the MyPoint.draw(canvas)
@Override
protected void onDraw(Canvas canvas) {
MyPoint p = null;
for (int i = 0; i < pointsList.size(); i++) {
p = (MyPoint) pointsList.remove(i);
p.draw(canvas);
}
}//end onDraw
//implemented in order to handel touch events
public boolean onTouch(View arg0, MotionEvent event) {
int action = event.getAction();
float currentX = event.getX();
float currentY = event.getY();
//log x and y coordinates
Log.v(this.getClass().getName().toString(), "X=" + currentX);
//log x and y coordinates
Log.v(this.getClass().getName().toString(), "Y=" + currentY);
if (action == MotionEvent.ACTION_DOWN) {
// log action down
Log.v(this.getClass().getName().toString(), "MotionEvent = ACTION_DOWN");
pointsList.add(new MyPoint(currentX, currentY));
this.invalidate();
} else if (action == MotionEvent.ACTION_MOVE) {
//log action move
Log.v(this.getClass().getName().toString(), "MotionEvent = ACTION_MOVE");
pointsList.add(new MyPoint(currentX, currentY));
this.invalidate();
} else if (action == MotionEvent.ACTION_UP) {
//log action move
Log.v(this.getClass().getName().toString(), "MotionEvent = ACTION_UP");
pointsList.add(new MyPoint(currentX, currentY));
this.invalidate();
}
//call invalidate in order to call trigger onDraw()
return true;
}//end onTouch()
}//end GameCanvas class
3）遊戲類是活動推出的GameCanvas查看
public class Game extends Activity {
GameCanvas newGameCanvas = null;
@Override
public void onCreate(Bundle savedInstanceState) {
//create GameCanvas object
newGameCanvas = new GameCanvas(this);
super.onCreate(savedInstanceState);
setContentView(newGameCanvas);
//
newGameCanvas.requestFocus();
}//end OnCreate
}//end Game class
那麼，我能說什麼：調試它。編寫代碼只是一個部分，讓它工作是另一個:)。嘗試找到你的問題：驗證觸摸是否進入你的視圖（請參閱onTouch（）的日誌），然後檢查每次觸摸後是否執行onDraw（應該是無效的結果），檢查列表（它是否有點..）等等......你很快就會縮小問題範圍，並且能夠確定bug – 2012-02-13 02:21:01
由於某些原因，他們沒有被記錄，我無法查看日誌。想到的一個問題是鼠標點擊/拖在emaulator被視爲觸摸事件 – cyber101 2012-02-13 03:15:03
只是一個瘋狂的猜測，嘗試addind setClickable（true），看看點擊和觸摸是否會通過 – 2012-02-13 23:34:49