aspx.cs里写个方法：
protected string SetFloor(int floor)
{
    if(floor>0)
        return "F"+floor;
    else
        return "B1";    
}

------解决方案--------------------
gridview行绑定里面处理下不也行么

C# code
    /// <summary>
    /// 数据行绑定
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            if (e.Row.Cells[1].Text == "0")//如果该行第1列为0 
            {
                e.Row.Cells[1].Text="B1";//替换
            }
            else if (e.Row.Cells[1].Text == "1")
            {
               e.Row.Cells[1].Text="F1";
            }
   
        }
    }