實現判斷用戶名是否已被占用:
第壹步:拖壹個textbox
<asp:textbox id="TextBox1" runat="server" Width="88px"></asp:textbox>
第二步:拖壹個自定驗證控件,指定驗證對象後,雙擊它
<asp:CustomValidator id="CustomValidator1" runat="server" ErrorMessage="用戶名已經存在,請重新選擇" ControlToValidate="TextBox1"
Display="Dynamic"></asp:CustomValidator>
第三步:在出來的源代碼中添加代碼:
private void CustomValidator1_ServerValidate(object source, System.Web.UI.WebControls.ServerValidateEventArgs args)
{
string accessString="Provider=Microsoft.Jet.oledb.4.0;Data Source="+Server.MapPath("database/user.mdb");
OleDbConnection conn=new OleDbConnection(accessString);
conn.Open();
string userName=args.Value;//獲取用戶名
string sqlstr="select count(*) from user1 where name1='"+ userName + "'";
OleDbCommand cmd=new OleDbCommand(sqlstr,conn);
int count1=Convert.ToInt32(cmd.ExecuteScalar());
//string rs=Convert.ToString(rs);
if(count1>0)//查找到數據庫已經存在該用戶名,則反饋不通過,否則通過
{args.IsValid=false;//表示網頁的控件有壹個沒通過則為false,都通過為true
}
else
{
args.IsValid=true;
}
conn.Close();
}