下面的代码是从本地上传图片，并显示出来。 我觉得代码没什么问题啊，可就是显示不出来！请帮忙看一下，指点一下，不胜感激！
public partial class q : System.Web.UI.Page
{
    Boolean fileok = false;
    protected void Page_Load(object sender, EventArgs e)
    {
    }
    protected void Button1_Click(object sender, EventArgs e)
{
    Response.Write(fileok);
    if (FileUpload1.HasFile)
    {
        string fileext = (FileUpload1.FileName).ToLower();
        string[] allowedextensions ={ ".jpg", ".bmp", ".gif", ".bng" };
        for (int i = 0; i < allowedextensions.Length; i++)
        {
            if (fileext == allowedextensions[i])
            {
                fileok = true;
            }
        }
    }
    if (FileUpload1.PostedFile.ContentLength > 1024000)
    {
        fileok = false;
    }
    if (fileok)
    {
        try
        {   FileUpload1.PostedFile.SaveAs(MapPath ("file/") + FileUpload1.PostedFile.FileName);
            Label1.Text = "上传文件成功";
            Image1.ImageUrl = MapPath ("file/") + FileUpload1.PostedFile.FileName;
        }
        catch
        {
            Label1.Text = "无法上传图片";
        }
    }
    else
    {
        Label1.Text = "文件类型不对或文件太大!";
    }
}
}

用的是FileUpload控件