asp:DataList ID="DataList1" runat="server" RepeatDirection="Horizontal" RepeatColumns="5"
CellSpacing="25">
ItemTemplate>
img src="%# Eval("FullName") %>" width="50" height="50" border="0" >
/ItemTemplate>
/asp:DataList>

string path = Server.MapPath("img");//獲取img文件夾的路徑
Response.Write(path);
DirectoryInfo di = new DirectoryInfo(path);
//DataList1.DataSource = di.GetFiles("*.jpg");只獲取jpg圖片
DataList1.DataSource = di.GetFiles();//獲取文件夾下所有的文件
DataList1.DataBind();