垂直搜寻栏无法通过viewmodel设置thumbtint

Question

这是我的垂直搜索栏代码。

public class VerticalSeekBar extends SeekBar {

public VerticalSeekBar(Context context) {
    super(context);
}

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

public VerticalSeekBar(Context context, AttributeSet attrs) {
    super(context, attrs);
}

protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(h, w, oldh, oldw);
}

@Override
protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(heightMeasureSpec, widthMeasureSpec);
    setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
}

protected void onDraw(Canvas c) {
    c.rotate(-90);
    c.translate(-getHeight(), 0);

    super.onDraw(c);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    if (!isEnabled()) {
        return false;
    }

    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_MOVE:
        case MotionEvent.ACTION_UP:
            setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));
            onSizeChanged(getWidth(), getHeight(), 0, 0);
            break;

        case MotionEvent.ACTION_CANCEL:
            break;
    }
    return true;
}

}

但是，当我尝试设置android:thumbtint="@{viewModel.thumbtint}"时，拇指色的颜色不会改变。我只能通过seekbar.thumb进行设置。

我希望能够以这种方式进行设置android:thumbtint="@{viewModel.thumbtint}"

有什么建议吗？