图片与Base64互转

/// <summary>
/// Base64转图片
/// </summary>
/// <param name="data"></param>
public Image Base64ToImage(string data)
{
    data = data.Replace("data:image/png;base64,", "").Replace("data:image/jgp;base64,", "").Replace("data:image/jpg;base64,", "").Replace("data:image/jpeg;base64,", "");//将base64头部信息替换
    byte[] bytes = Convert.FromBase64String(data);
    MemoryStream memStream = new MemoryStream(bytes);
    Image mImage = Image.FromStream(memStream);
    Bitmap bp = new Bitmap(mImage);
    bp.Save(DateTime.Now.ToString("yyyyMMddHHss") + ".png", System.Drawing.Imaging.ImageFormat.Png);//注意保存路径
    return bp;
}
/// <summary>
/// 图片转Base64
/// </summary>
/// <param name="img"></param>
/// <returns></returns>
public string ImageToBase64(Image img)
{
    try
    {
        Bitmap bmp = new Bitmap(img);
        MemoryStream ms = new MemoryStream();
        bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        byte[] arr = new byte[ms.Length];
        ms.Position = 0;
        ms.Read(arr, 0, (int)ms.Length);
        ms.Close();
        return Convert.ToBase64String(arr);
    }
    catch (Exception ex)
    {
        return null;
    }
}