一个绑定的radiobuttomlist 为什么显示的时候会比数据库少一项?

Question

很奇怪,还有就是怎么让它第一项默认被选中?

Answer 1

把绑定代码贴出来嘛，RadioButtonList1.Items[0].Selected = true;//0是第一项

Answer 2

string sql="select * from vote order by id ";        string conn = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("vote.mdb");        OleDbConnection oleconn = new OleDbConnection(conn);        oleconn.Open();        OleDbCommand cmd = new OleDbCommand(sql, oleconn);
        OleDbDataReader dr = cmd.ExecuteReader();
        while(dr.Read())
        {
            rdl.DataSource = dr;
            rdl.DataTextField = "name";
            rdl.DataValueField = "name";
            rdl.DataBind();          
            
        }        oleconn.Close();链接数据库代码在这里......

Answer 3

string sql="select * from vote order by id ";        string conn = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("vote.mdb");        OleDbConnection oleconn = new OleDbConnection(conn);        oleconn.Open();        OleDbCommand cmd = new OleDbCommand(sql, oleconn);
        OleDbDataReader dr = cmd.ExecuteReader();        rdl.DataSource = dr;
        rdl.DataTextField = "name";
        rdl.DataValueField = "name";
        rdl.DataBind();          
           
        oleconn.Close();

Answer 4

直接用dr给rdl.DataSource赋值就可以了上面记得 dr.Close();

Answer 5

不能 while(dr.Read())后再绑定，这时候一条数据已经被Read掉了，你上面的代码中不需要用while来判断，直接用
rdl.DataSource = dr;
rdl.DataTextField = "name";
rdl.DataValueField = "name";
rdl.DataBind(); 
就可以了