菜鸟遇到有关问题了。大家帮帮忙。

初学者遇到问题了。。大家帮帮忙。。。
前台。。 ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>无标题页</title>
<style type="text/css">
.style1
{
height: 106px;
}
</style>
</head>
<body>
<form id="form1" runat="server">

<div class="style1">

用户名<asp:TextBox ID="TextBox1" runat="server" Height="22px"></asp:TextBox>
密码 <asp:TextBox ID="TextBox2" runat="server" Height="22px"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" Height="26px" Width="56px" />
<br /><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

</div>
</form>
</body>
</html>

后台。。 ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓

Imports System.Data.SqlClient
Imports System.Data
Partial Class _Default
Inherits System.Web.UI.Page

Protected Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs)
'创建数据库连接↓
Dim conn As SqlConnection
Dim comd As SqlCommand
Dim datar As SqlDataReader
Dim sql As String

conn = New SqlConnection("Server=local;user id=sa;pwd=123321;database=liu")
conn.Open()
'执行sql语句↓
sql = "SELECT 用户名 FROM 用户"
comd = New SqlCommand(sql, conn)
datar = comd.ExecuteReader()
conn.Close()
Label1.text = datar
End Sub

End Class

大家帮忙看看。数据库连接对了吗？还有就是假如我想查看那个datar到底显示的什么。。在哪可以打印出来？
[解决办法]
不对，参考msdn代码


private static void CreateCommand(string queryString,
    string connectionString) 
 
{
    using (SqlConnection connection = new SqlConnection(
               connectionString))
    {
        connection.Open();

        SqlCommand command = new SqlCommand(queryString, connection);
        SqlDataReader reader = command.ExecuteReader();
        while (reader.Read())
        {
            Console.WriteLine(String.Format("{0}", reader[0]));
        }
    }
}

[解决办法]
If datar.Read() Then
Label1.text = datar(字段名)
Else

菜鸟遇到有关问题了。大家帮帮忙。

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