各位高手帮帮忙..关于“System.Data.SqlClient.SqlDataAdapter”并不包含“GetString”的定义怎么解决

Question

“System.Data.SqlClient.SqlDataAdapter”并不包含“GetString”的定义 要怎样解决... 答对的给满分

Answer 1

while (dr.Read())
                {                    ListViewItem item1=new ListViewItem();
                    item1.Text=dr.GetString(1) + "(" + dr.GetString(0) + ")";
                    item1.Tag=dr.GetString(0);
                    item1.ImageIndex=0;
                    listView1.Items.Add(item1);
                }
                con.Close();
            }
指着不包含GetString的定义..帮帮忙..

Answer 2

应该都是SqlDataAdapter 这个要改成SqlDataReader，因为SqlDataAdapter 没有GetString（）；

Answer 3

while (dr.Read()) 
                {                     ListViewItem item1=new ListViewItem(); 
                    item1.Text=dr.GetString(1) + "(" + dr.GetString(0) + ")"; 
                    item1.Tag=dr.GetString(0); 
                    item1.ImageIndex=0; 
                    listView1.Items.Add(item1); 
                } 
                con.Close(); 
            } 
里面说上下文不存在dr..怎样定义..谢谢..

Answer 4

可以这么定义：SqlDataReader dr = new SqlDataReader(); 
另外你给你个网址，你看看http://www.cnweblog.com/maomao2008/articles/276901.html

Answer 5

可以：你前面应该有SqlCommand myCommand = new SqlCommand(mySelectQuery,myConnection, myTrans);这句话吧。
那么你可以写成：SqlDataReader myReader = myCommand.ExecuteReader();

Answer 6

不可以...前面没有这句话.. if (comboBox2.DataSource != null && comboBox2.Text.Trim() != "")
            {
                con.Open();
                
                string sql = "select year(enrolmenttime) from classinfo where classid = " + comboBox2.SelectedValue;
                SqlCommand  cmd=new SqlCommand (sql,con);
                int rxnf = Int32.Parse(cmd.ExecuteScalar().ToString());
                sql = "select length from classinfo where classid = " + comboBox2.SelectedValue.ToString().Trim();
                cmd.CommandText=sql;
                int nianzhi = Int32.Parse(cmd.ExecuteScalar().ToString());
                int nf = rxnf;
                comboBox3.Items.Clear();
                for (int i=1;i<=nianzhi*2;i++)
                {
                    comboBox3.Items.Add(nf + "" + ((i+1)%2+1));
                    if((i%2)==0)
                    nf++;
                }                listView1.Items.Clear();
                sql = "select studentnumber,name from studentinfo   where classid = " + comboBox2.SelectedValue + " order by studentnumber asc";
                cmd.CommandText=sql;
                SqlDataReader reader = cmd.ExecuteReader();
                SqlDataReader dr = new SqlDataReader();  
                while (dr.Read())
                {                    ListViewItem item1=new ListViewItem();
                    item1.Text=dr.GetString(1) + "(" + dr.GetString(0) + ")";
                    item1.Tag=dr.GetString(0);
                    item1.ImageIndex=0;
                    listView1.Items.Add(item1);
                }
                con.Close();
            }
            else
            {
                comboBox3.Items.Clear();
                comboBox3.SelectedValue=-1;
                listView1.Clear();
            }
        
        }
这是所有的代码..new SqlDataReader() 说这个没构造函数

Answer 7

把SqlDataReader dr = new SqlDataReader();   去掉。
直接用 while (dr.Read()) 改成 while (reader.Read()) 试试