我正在尝试应用图片名称，但图片未加载。

if (!IsPostBack)
{
    string[] str = new string[] { "Select","Anniversary","Birthday","Graduation","Sympathy" };
    for (int i = 0; i < str.Length; i++)
    {
        DDl1.Items.Add(str[i]);
    }  // this Loop creates the items in the drop down list

    {
        string str = DDl1.Text;
        Image1.ImageUrl="~/Media"+str+".png";
    } // This is how i was trying to call the images from the Media folder in my project