在android中放大/缩小或拖动后获取画布坐标

我正在开发一个应用程序，我在其中粘贴图像，在画布上画画。此应用程序还可以放大/缩小画布或将其拖动到不同的位置。 我的问题是：缩放或拖动画布后，无法获得正确的画布坐标。我想在缩放或拖动画布后绘制手指绘画，但无法检索到我触摸过的正确位置..：( 我也是新来的蜜蜂。这是密码

@Override
public void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    canvas.save();
    //canvas.translate(mPosX, mPosY);
    canvas.scale(mScaleFactor, mScaleFactor, super.getWidth() * 0.5f,
            super.getHeight() * 0.5f);
    mIcon.draw(canvas);
    for (Path path : listPath) {
        canvas.drawPath(path, paint);
    }
    canvas.restore();
}

public TouchExampleView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);

}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    // Let the ScaleGestureDetector inspect all events.
    mScaleDetector.onTouchEvent(ev);

    final int action = ev.getAction();
    switch (action & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();

        mLastTouchX = x;
        mLastTouchY = y;
        mActivePointerId = ev.getPointerId(0);
        break;
    }

    case MotionEvent.ACTION_MOVE: {
        final int pointerIndex = ev.findPointerIndex(mActivePointerId);
        final float x = ev.getX(pointerIndex);
        final float y = ev.getY(pointerIndex);

        // Only move if the ScaleGestureDetector isn't processing a gesture.
        if (!mScaleDetector.isInProgress()) {
            final float dx = x - mLastTouchX;
            final float dy = y - mLastTouchY;

            mPosX += dx;
            mPosY += dy;

            invalidate();
        }

        mLastTouchX = x;
        mLastTouchY = y;

        break;
    }

    case MotionEvent.ACTION_UP: {
        mActivePointerId = INVALID_POINTER_ID;
        break;
    }

    case MotionEvent.ACTION_CANCEL: {
        mActivePointerId = INVALID_POINTER_ID;
        break;
    }

    case MotionEvent.ACTION_POINTER_UP: {
        final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
        final int pointerId = ev.getPointerId(pointerIndex);
        if (pointerId == mActivePointerId) {
            // This was our active pointer going up. Choose a new
            // active pointer and adjust accordingly.
            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastTouchX = ev.getX(newPointerIndex);
            mLastTouchY = ev.getY(newPointerIndex);
            mActivePointerId = ev.getPointerId(newPointerIndex);
        }
        break;
    }
    }

    float objectNewX,objectNewY;
    if (mScaleFactor >= 1) {
        objectNewX = ev.getX() + (ev.getX() - super.getWidth() * 0.5f) * (mScaleFactor - 1);
        objectNewY = ev.getY() + (ev.getY() - super.getHeight() * 0.5f) * (mScaleFactor - 1);
    } else {
        objectNewX = ev.getX() - (ev.getX() - super.getWidth() * 0.5f) * (1 - mScaleFactor);
        objectNewY = ev.getY() - (ev.getY() - super.getHeight() * 0.5f) * (1 - mScaleFactor);
    }

    if (ev.getAction() == MotionEvent.ACTION_DOWN) {
        path = new Path();
        path.moveTo(objectNewX,objectNewY);
        path.lineTo(objectNewX,objectNewY);
    } else if (ev.getAction() == MotionEvent.ACTION_MOVE) {
        path.lineTo(objectNewX,objectNewY);
        listPath.add(path);
    } else if (ev.getAction() == MotionEvent.ACTION_UP) {
        path.lineTo(objectNewX,objectNewY);
        listPath.add(path);
    }

    return true;
}

private class ScaleListener extends
        ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        mScaleFactor *= detector.getScaleFactor();

        // Don't let the object get too small or too large.
        mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));

        invalidate();
        return true;
    }
}

---

最后是我自己做的

通过将此公式应用于（px，py）坐标绘制所有内容：

float px = ev.getX() / mScaleFactor + rect.left;
float py = ev.getY() / mScaleFactor + rect.top;
rect = canvas.getClipBounds();
//Get them in on Draw function and apply above formula before drawing

---

希望这会有所帮助。

我无法获得正确的画布坐标。你必须更具体一些。比例本身是否有效？定义你期望的正确画布坐标？它们现在有什么问题？尝试缩放图像，然后在画布上绘制一些东西。然后你就会知道。同时取消对画布的注释。翻译（mPosX，mPosY）；如果我在平移或缩放之前在画布上绘制一些东西，效果会很好。但在平移/缩放之后，效果不会很好。即使在缩放或平移之后，我也需要一种正确绘制的方法…：>嘿，awais，我也在做同样的事情。我没有正确理解你的解决方案。你能分享你的代码或帮助我吗？你的pr在哪里问题？？？在我的例子中，我必须在屏幕上绘制一些东西，我使用float x=ev.getX（）/mScaleFactor+rect.left；代替event.getX（）；与Y轴类似。Rect是绘制画布的剪贴簿。我们必须将其保存在某个矩形变量中。它们在onDraw函数中不断更新…检查此项，如果您能提供帮助，它将非常棒…再次需要您的帮助…感谢您的偏移值，我已经实现了缩放。现在，我使用Scal添加了滚动eGestureDetector.SimpleOnScaleEgestureListener-onScroll方法…现在我又坚持使用偏移量了？如果你能帮我解决这两个值x和y是我点击区域的偏移量，那就又是gr8了？或者我需要用上面的x和y值更新我的绘制对象？你需要更新绘制对象吗根据上面提到的x和y的相对值进行ss。谢谢，伙计！！！我已经知道了我的对象的移动位置。。但是我不知道如何将可点击区域移动到我正在处理的相同位置。。如果你有任何想法，请提出建议！！！我尝试了getHitRect并将偏移量添加到其中？很好！！！兄弟再次需要你的帮助…我将滚动功能添加到了缩放后的布局..再次卡在偏移点？查看此链接的答案粘贴一些代码男孩…我猜上述计算应适用于缩放..：\

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    clipBounds_canvas = canvas.getClipBounds();
    /////Do whatever you want to do..!!!            
};

@Override
public boolean onTouchEvent(MotionEvent ev) {
    int x = ev.getX() / zoomFactor + clipBounds_canvas.left;
    int y = ev.getY() / zoomFactor + clipBounds_canvas.top;
    //Use the above two values insted of ev.getX() and ev.getY();
}