在Android中，什么時候調用Interface？

Question

這是我第一次嘗試Android游戲。 我需要繪制一條從屏幕中心開始的路徑，並使用OnGlobalLayoutListener獲取屏幕中心坐標。 為了將中心坐標傳遞給View類，我使用了Interface 。 現在，假設接口正在工作，則傳遞0,0，因為繪制的路徑從我的相對布局的左上方開始。 我得到正確的坐標，因為現在我將它們傳遞給TextView以便可以看到坐標，但是它們沒有傳遞給View類，因為路徑從左上角開始，而不是我的中心相對布局。 所以我想我的問題是： 接口是否在onCreate完成之前被觸發？ 如果是這樣，如何在觸發界面之前將中間屏幕數據獲取到界面？ 獲取屏幕數據后可以以某種方式觸發接口嗎？ 這是我正在使用的類，首先是Main Activity：

public class Game1 extends Activity implements GBoardValueSetter {
DrawPath dp;
TextView gameScore_TV, gameTime_TV;
private CountDownTimer mainGameCD;
private boolean mainGameTimerHasStarted = false;
private final long mainCDTime = 30 * 1000;
private final long mainCDInterval = 1 * 1000;

// ---GameBoard variables
RelativeLayout root_RL, gBoardInfo_RL, gBoard_RL;
LayoutInflater LayInf = null;
View root_VUE, gBoardInfo_VUE;
LayoutParams root_LP, gBoardInfo_LP, gBoard_LP;
int xScr2Int, yScr2Int, xScrInt, yScrInt, xCenterInt, yCenterInt;
String xCenterStr, yCenterStr, xHStr, yWStr;
float xCenter_FL, yCenter_FL;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    overridePendingTransition(R.anim.cutin, R.anim.cutout);

    root_RL = new RelativeLayout(this);
    root_LP = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.MATCH_PARENT,
            RelativeLayout.LayoutParams.MATCH_PARENT);
    root_RL.setId(1);
    root_RL.setBackgroundColor(Color.WHITE);
    root_RL.setLayoutParams(root_LP);
    setContentView(root_RL);

    createBlankGBoard();
    addDP();
}// --- END onCreate


//--- Interface call
@Override
public void passGBCenterIntValuesInterface(int xC_IInt, int yC_IInt) {
    xC_IInt = xCenterInt;
    yC_IInt = yCenterInt;
    dp.setCenterInt(xC_IInt, yC_IInt);

}//--- END Interface call


public void createBlankGBoard(){
    LayInf = (LayoutInflater) getApplicationContext().getSystemService(
            Context.LAYOUT_INFLATER_SERVICE);
    gBoardInfo_VUE = LayInf.inflate(R.layout.game1_info, null);
    gBoardInfo_LP = new LayoutParams(LayoutParams.MATCH_PARENT,
            LayoutParams.WRAP_CONTENT);
    gBoardInfo_LP.addRule(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.TRUE);
    gBoardInfo_VUE.setId(2);
    gBoardInfo_VUE.setLayoutParams(gBoardInfo_LP);
    gameTime_TV = (TextView) gBoardInfo_VUE.findViewById(R.id.game1_timeValue2_TV);
    gameScore_TV = (TextView) gBoardInfo_VUE.findViewById(R.id.game1_scoreValue2_TV);
    root_RL.addView(gBoardInfo_VUE);

    gBoard_RL = new RelativeLayout(this);
    gBoard_LP = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.MATCH_PARENT,
            RelativeLayout.LayoutParams.MATCH_PARENT);
    gBoard_LP.addRule(RelativeLayout.BELOW, gBoardInfo_VUE.getId());
    gBoard_LP.setMargins(10, 10, 10, 10);
    gBoard_RL.setLayoutParams(gBoard_LP);
    gBoard_RL.setBackgroundColor(Color.MAGENTA);
    root_RL.addView(gBoard_RL);
    getGameBoardNumbers();
}

public void addDP(){
    root_RL.removeView(gBoard_RL);
    dp = new DrawPath(this);
    gBoard_RL.setBackgroundColor(Color.CYAN);
    gBoard_RL.addView(dp);
    root_RL.addView(gBoard_RL);

}

//-- Get GameBoard info using oGLL
public void getGameBoardNumbers(){
    gBoard_RL.getViewTreeObserver().addOnGlobalLayoutListener(
            NumbersoGLL);   
}

//-- oGLL
OnGlobalLayoutListener NumbersoGLL = new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {

        xScrInt = gBoard_RL.getWidth();
        yScrInt = gBoard_RL.getHeight();

        xScr2Int = gBoard_RL.getWidth()/2;
        yScr2Int = gBoard_RL.getHeight()/2;
        xCenterInt = gBoard_RL.getLeft() + xScr2Int;
        yCenterInt = gBoard_RL.getTop() + yScr2Int;

        xHStr = String.valueOf(xScrInt);
        yWStr = String.valueOf(yScrInt);

        xCenter_FL = (float)xCenterInt;
        yCenter_FL = (float)yCenterInt;

        String xCInt_Str = String.valueOf(xCenterInt);
        String yCInt_Str = String.valueOf(yCenterInt);

        gameScore_TV.setText(xCInt_Str + ", " + yCInt_Str);


    }
};
}

這是View類：

public class DrawPath extends View {
Paint paint = new Paint();
Path path = new Path();
private int xC_Int, yC_Int;

class Pt {
    float x, y;

    Pt(float _x, float _y) {
        x = _x;
        y = _y;
    }

}

public void setCenterInt(int xC_IInt, int yC_IInt){
    this.xC_Int = xC_IInt;
    this.yC_Int = yC_IInt;
}

Pt[] thePath = { new Pt(xC_Int, yC_Int),
        new Pt(200, 200),
        new Pt(200, 500),
        new Pt(400, 500)
        };

public DrawPath(Context context) {
    super(context);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    paint.setColor(Color.RED);
    paint.setStrokeWidth(7);
    paint.setStyle(Paint.Style.STROKE);
    path.moveTo(thePath[0].x, thePath[0].y);
    for (int i = 1; i < thePath.length; i++) {
        path.lineTo(thePath[i].x, thePath[i].y);
    }
    canvas.drawPath(path, paint);
}
}

和接口類：

public interface GBoardValueSetter {

void passGBCenterIntValuesInterface(int xC_IInt, int yC_IInt);

}

Answer 1

在對活動的接口調用中，分配從調用中獲取的參數：

public void passGBCenterIntValuesInterface(int xC_IInt, int yC_IInt) {
    xC_IInt = xCenterInt; <-- RIGHT THERE
    yC_IInt = yCenterInt; <-- RIGHT THERE
    dp.setCenterInt(xC_IInt, yC_IInt);

}//--- END Interface call

xCenterInt和yCenterInt可能為0