本Demo来自简书https://www.jianshu.com/p/9e774990bdb5 对大佬的分享进行学习与改进 int accurateEnd = reachedPartEnd - progressHeight / 2; int accurateStart = 0 + progressHeight / 2; if (accurateEnd > accurateStart) { canvas.drawLine(accurateStart, lineY, accurateEnd, lineY, mPaint); } else { canvas.drawLine(accurateStart, lineY, accurateStart, lineY, mPaint); }