Android:将数据传递到自定义 View 类中？

Question

我正在用 Android 开发我的第一款游戏。在游戏的一部分中，我正在绘制一条路径，我希望该路径从 RelativeLayout 的中心开始。我已成功获取中心坐标，但现在我需要将这些坐标 (int xCenterInt, yCenterInt;) 传递到我的自定义 View ，而这正是我无法弄清楚的。我无法让 Intents 工作，除非我做错了 Intents。那么如何将我的 int 值传递到我的自定义 View 类中呢？这是我在主 Activity 中使用的获取中心坐标的方法:

public void getBoardNumbers() {
    gBoard_RL.getViewTreeObserver().addOnGlobalLayoutListener(NumbersoGLL);
}


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;

        //---- How do I get xCenterInt, yCenterInt to my DrawPath Class?

    }
};

这是我的自定义 View 类，需要在其中插入坐标:

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

//--- The coordinates Integers need to go here:
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);
}// --- END onDraw

class Pt {
    float x, y;

    Pt(float _x, float _y){
        x = _x;
        y = _y;
    }
}//--- END PT
}

Answer 1

您可以通过在 DrawPath 类中为 xCenterInt 和 yCenterInt 创建一个 setter - getter 来实现这一点，示例:

public class DrawPath extends View {
Paint paint = new Paint();
Path path = new Path();
int xC_Int, yC_Int;
int xCenterInt, yCenterInt; //create new variables

//your other codes

public void setxCenterInt(int setxCenterInt) {
   this.setxCenterInt = setxCenterInt;
}

public int getxCenterInt() {
   return setxCenterInt;
}

//do the same for yCenterInt

之后，使用我们之前创建的setter-getter:

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;

        //use your DrawPath instance
        myDrawPathInstance.setxCenterInt(xCenterInt);
        //do the same for yCenterInt
    }
};