How to get the url of a Hyperlink-or-Picture column to WebPart?

I am Reading some Sample Codes. The list has 5 columns: Title, Name, Address, Age and Picture.  The type of information in Picture column is Hyperlink or Picture and Format Url as picture.

Then,  Function Page_Load of WebPart's ascx file is like:

protected void Page_Load(object sender, EventArgs e)
        {
            SPWeb ospweb = SPContext.Current.Web;
            SPList oList = ospweb.Lists["ChangleXiaoqu"];
            SPListItemCollection collItem = oList.GetItems("Name", "Age", "Address", "Pictrue");
            Random random = new Random();
            int RndItem = random.Next(1, collItem.Count + 1);
            SPListItem oItem = collItem[RndItem - 1];
            //Please note this line
	    this.ImgAuthor.ImageUrl = SPEncode.HtmlEncode(oItem["Pictrue"].ToString().TrimEnd('?', '.', ',', ' '));
            this.Name.Text = oItem["Name"].ToString();
            this.Age.Text = SPEncode.HtmlEncode(oItem["Age"].ToString());
            this.Address.Text = SPEncode.HtmlEncode(oItem["Address"].ToString());
        }

There are errors on 

this.ImgAuthor.ImageUrl = SPEncode.HtmlEncode(oItem["Pictrue"].ToString().TrimEnd('?', '.', ',', ' '));

If this line is commented, it will be ok!

So, How to get the url of a Hyperlink-or-Picture column to WebPart?