public partial class frmBook : Form
    {
        public frmBook()
        {
            InitializeComponent();
        }
        public static string str = "";
        public static string strConn = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=db_LibraryMIS;Data Source=2011-20120218ZM";
        //在dvgBook空间上显示图书表的数据
        public void showinf()
        {
            using (SqlConnection con = new SqlConnection(strConn))
            {
                DataTable dt = new DataTable();                               //内存中开辟一个内存数据表
                SqlDataAdapter da = new SqlDataAdapter("select BID as 图书编号,BName as 图书名称,BWrite as 作者,BPublish as 出版社,BDtate as 出版日期,BPrice as 价格,BNum as 数量,BType as 类型,BRemark as 备注 from tb_Book order by BID", con);
                da.Fill(dt);
                this.dvgBook.DataSource = dt.DefaultView;
            }
        }
        private void frmBook_Load(object sender, EventArgs e)
        {
            showinf();
        }
DataGridView控件如下图显示空空的：

public static string str = "";
 你这个是干吗用的？

噢，那个是后面用于记录DataGridView控件中指定单元格信息的字段

  DataGridView绑定数据源时，this.dvgBook.DataSource = dt.DefaultView;后边必须加this.dvgBook.DataBind().