c#问题 点一下button轮流显示图片（用picturebox）怎么写程序？

private ImageList imgList = new ImageList();
private int imgIndex = 0;

private initImageList()
{
imgList.Add(Image.FromFile(@"d:\\aaa.jpg"));
imgList.Add(Image.FromFile(@"d:\\bbb.jpg"));
imgList.Add(Image.FromFile(@"d:\\ccc.jpg"));
}

private void FrmImg_Load()
{
initImageList();
}

private void button1_Click(object sender,Eventarg e)
{
if(i >= imgList.Images.Count)
{
i = 0;
}
picturebox1.Image = imgList[i];
i++;
}