无法在 canvas 上绘制形状

Question

我创建了一个自定义视图，以便我可以在点击时绘制形状并执行一些操作

我创建了一个名为 fillOnTouch(); 的方法； 应该使用油漆和 canvas 作为参数，然后在 canvas 上绘制彩色圆圈，当我从 TouchEvent 调用此方法时，它不会在 canvas 上绘制，因此我尝试在 Touchevent 上创建彩色路径然后在 onDraw 方法上绘制这条路径，但结果是相同的，canvas 中没有绘制形状，因为它应该是

触摸事件

 @Override
public boolean onTouchEvent(MotionEvent event) {
    float x = event.getX();
    float y = event.getY();
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            touchStart(x, y);
            coloredCircles.addCircle(x, y, 20, Path.Direction.CW);
            checkStrokeInRightPath(x, y);
            FillLetters.fillCircleOnTouch(x, y, fillCircles, dataLists, mCanvas);
            invalidate();
            break;
        case MotionEvent.ACTION_MOVE:
            touchMove(x, y);
            checkStrokeInRightPath(x, y);
            FillLetters.fillCircleOnTouch(x, y, fillCircles, dataLists, mCanvas);
            coloredCircles.addCircle(x, y, 20, Path.Direction.CW);
            invalidate();
            break;

        case MotionEvent.ACTION_UP:
            touchUp();
            checkStrokeInRightPath(x, y);
            FillLetters.fillCircleOnTouch(x, y, fillCircles, dataLists, mCanvas);
            coloredCircles.addCircle(x, y, 20, Path.Direction.CW);
            invalidate();
            break;
    }

    return true;
}

fillOnTouch 方法

 public static void fillCircleOnTouch(float x, float y, Paint paint, List<List<Integer>> circleList, Canvas canvas) {

    List<Integer> xPoints, yPoints, circleCount;
    int r = DrawLetters.radius;
    float xStart, xEnd, yStart, yEnd;
    if (!circleList.isEmpty()) {
        xPoints = circleList.get(0);
        yPoints = circleList.get(1);
        circleCount = circleList.get(2);
        if (iterationCount < xPoints.size()) {
            float nextCircleX = xPoints.get(iterationCount);
            float nextCircleY = yPoints.get(iterationCount);
            paint.setColor(blendColors("#FFFF00", "#0000FF", (circleCount.get(iterationCount)) * ((float) (1.0 / xPoints.size()))));
            xStart = nextCircleX - r;
            xEnd = nextCircleX + r;
            yStart = nextCircleY - r;
            yEnd = nextCircleY + r;
            Range<Float> xRange = new Range<>(xStart, xEnd);
            Range<Float> yRange = new Range<>(yStart, yEnd);
            if (xRange.contains(x) && yRange.contains(y)) {                  
                canvas.drawCircle(nextCircleX, nextCircleY, r, paint);                   
                iterationCount++;
            }
        }
    }
}

onDraw 方法

  @Override
protected void onDraw(Canvas canvas) {
    // save the current state of the canvas before,
    // to draw the background of the canvas
    canvas.save();

    // DEFAULT color of the canvas
    int backgroundColor = Color.WHITE;
    mCanvas.drawColor(backgroundColor);

    // now, we iterate over the list of paths
    // and draw each path on the canvas
    for (Stroke fp : paths) {
        mPaint.setColor(fp.color);
        mPaint.setStrokeWidth(fp.width);
        mCanvas.drawPath(fp.path, mPaint);
    }

    if (coloredCircles != null && !coloredCircles.isEmpty()) {

        canvas.drawPath(coloredCircles, mPaint);
    }


    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
    canvas.restore();
}