Question

我使用以下代码填充我的DropDownList;

 while (myDataReader.Read())
                {

                    DropDownList1.Items.Add(myDataReader[0].ToString());
                    DropDownList1.DataValueField = myDataReader[1].ToString();
                    DropDownList1.DataTextField = myDataReader[0].ToString();

                }

但无论DropDownList1中选择了什么，DataValue始终是从while循环读取的最后一个DataValue。

我做错了什么？

Answer 1

我没有使用myDataReader，而是将dropdownList绑定到数据源

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString);

SqlCommand cmd = new SqlCommand("Select * from students", con);

SqlDataAdapter da = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();
da.Fill(ds);

DropDownList1.DataTextField = ds.Tables[0].Columns["FullName"].ToString();
DropDownList1.DataValueField = ds.Tables[0].Columns["id"].ToString();

DropDownList1.DataSource = ds.Tables[0];
DropDownList1.DataBind();

Answer 2

因此，您似乎希望将数据库列名称用作数据值字段。但实际上，您实际上是将列值（而不是列名称）作为数据值字段提供。您的代码应如下所示：

DropDownList1.DataValueField = "ValueColumn"; //name of the value column, such as 'id' from the database
DropDownList1.DataTextField = "NameColumn"; //name of the descriptive column, such as 'name'
while (myDataReader.Read())
{
     //also, we removed the 'ToString' because we want to provide the datarow object, not the converted string value
     DropDownList1.Items.Add(myDataReader[0]);
}

DropDownList填充失败; DataValueField始终是最低值

2 个答案: