android折线图圆点的动画,android – 如何在折线图中的高亮点上绘制圆圈？

您可以使用 ValueAnimator 来实现动画效果。以下是一个示例代码，可以在折线图的高亮点上绘制圆圈并添加动画效果：

1. 首先，在图表上绘制高亮点时，将其包装在一个圆圈 Drawable 中：

private Drawable getHighlightDrawable() {
    GradientDrawable drawable = new GradientDrawable();
    drawable.setShape(GradientDrawable.OVAL);
    drawable.setColor(Color.GREEN);
    drawable.setSize(20, 20);
    drawable.setStroke(2, Color.WHITE);
    return drawable;
}

2. 然后，在绘制高亮点时，同时将圆圈 Drawable 绘制在其上方：

private void drawHighlight(Canvas canvas, LineDataSet dataSet, int xIndex, int yIndex, Highlight highlight) {
    // Get the x and y coordinates of the highlight point
    float x = dataSet.getXValue(xIndex);
    float y = dataSet.getYValue(yIndex);

    // Draw the highlight point
    float[] pts = new float[]{x, y};
    mChart.getTransformer(dataSet.getAxisDependency()).pointValuesToPixel(pts);
    canvas.drawCircle(pts[0], pts[1], 10, mHighlightPaint);

    // Draw the circle Drawable on top of the highlight point
    Drawable drawable = getHighlightDrawable();
    int width = drawable.getIntrinsicWidth();
    int height = drawable.getIntrinsicHeight();
    drawable.setBounds((int) (pts[0] - width / 2), (int) (pts[1] - height / 2), (int) (pts[0] + width / 2), (int) (pts[1] + height / 2));
    drawable.draw(canvas);
}

3. 最后，在高亮点上添加 ValueAnimator 动画，使其缩放大小：

private void animateHighlight(final int duration, final int repeatCount, final Highlight highlight) {
    final Drawable drawable = getHighlightDrawable();
    final int width = drawable.getIntrinsicWidth();
    final int height = drawable.getIntrinsicHeight();
    final float start = 1.0f;
    final float end = 1.5f;
    final ValueAnimator anim = ValueAnimator.ofFloat(start, end);
    anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            float value = (float) animation.getAnimatedValue();
            int scaledWidth = (int) (width * value);
            int scaledHeight = (int) (height * value);
            drawable.setBounds((int) (highlight.getX() - scaledWidth / 2), (int) (highlight.getY() - scaledHeight / 2), (int) (highlight.getX() + scaledWidth / 2), (int) (highlight.getY() + scaledHeight / 2));
            mChart.invalidate();
        }
    });
    anim.setInterpolator(new LinearInterpolator());
    anim.setDuration(duration);
    anim.setRepeatCount(repeatCount);
    anim.start();
}

在您想要添加动画的位置调用 animateHighlight() 方法即可。