How to auto check existing data in textbox without refreshing the page.

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Hi, I want to check data (UserID) on textbox without refreshing the page. Actually I want when user write any UserID in textbox then it check from the db & result on same line without refreshing the page (i.e. UserID available or UserID not available). I am using ajax for this but still page is refreshing. See my Code:

ASP.NET

<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <asp:TextBox ID="UserID" runat="server" CssClass="w254" AutoPostBack="True" OnTextChanged="UserID_TextChanged"></asp:TextBox>
         <asp:Label ID="lbl_error" runat="server" Text="Label" Visible="False" Font-Size="Small"></asp:Label>
        <br />
        <br />
    </ContentTemplate>
</asp:UpdatePanel>
<asp:TextBox ID="FirstName" runat="server"></asp:TextBox>

Code :

C#

protected void UserID_TextChanged(object sender, EventArgs e)
   {
       lbl_error.Visible = true;
       int chk = 0;
       string chk_existing_email = "select userID from tbl_Registration where userID ='" + UserID.Text + "' ";
       chk = new CommonClass().Is_exist(chk_existing_email);
       if (chk == 1)
       {
           UserID.Focus();
           lbl_error.Text = "UserID is available!";
           lbl_error.ForeColor = System.Drawing.Color.Green;
       }
       else
       {
           UserID.Focus();
           lbl_error.Text = "UserID is not available!";
           lbl_error.ForeColor = System.Drawing.Color.Red;
       }
   }

Posted 25-Mar-13 3:26am

Mas11

Updated 25-Mar-13 3:52am

v2

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Comments

Raje_ 25-Mar-13 9:33am

Use Web service for that.

Mas11 25-Mar-13 9:51am

Hi Raje_ I have created web Service for this but how could I Call this on Textbox. Really appreciate your suggestion.

[System.Web.Services.WebMethodAttribute(), System.Web.Script.Services.ScriptMethodAttribute()]
public static string[] GetCompletionList(string prefixText, int count, string contextKey)
{
SqlConnection conn;
SqlCommand cmd;
string cmdString = "select userID from tbl_Registration where userID = '" + prefixText + "'";
conn = new SqlConnection(ConfigurationManager.AppSettings["mas"]);
cmd = new SqlCommand(cmdString, conn);
conn.Open();
SqlDataReader myReader;
List<string> returnData = new List<string>();
myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
while (myReader.Read())
{
returnData.Add(myReader["userID"].ToString());
}
return returnData.ToArray();
}

2 solutions

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ZurdoDev · Answer 1 · 2013-03-25T03:55:00

Solution 1

It is because you have AutoPostback = True on your textbox, so it is going to postback. Use the JavaScript event, OnChange or Onblur and use jquery's .ajax() method instead.

Posted 25-Mar-13 3:55am

ZurdoDev

Comments

Mas11 25-Mar-13 10:00am

Thanks Ryan I'll try by this. But any suggestion over my given code.

ZurdoDev 25-Mar-13 10:02am

Not if you don't want a postback. Your code IS postback. You could use an updatepanel but I have never liked them much, personally.

Raje_ · Answer 2 · 2013-03-25T04:04:00

You can use Jquery to call Web Service:-

JavaScript

$("#txtSearch" ).autocomplete({
 source: function(request, response) {
         $.ajax({
     url: "WebService/search.asmx/SearchResult",
     dataType: "json",
     contentType: "application/json; charset=utf-8",
     type: "POST",
     data: "{ 'strKey': '" + request.term + "'}",
             //strKey is your parameter of your web mehod
             success: function (data) {
                  response($.map(data.d, function(item) {
                     return {
                         label: item.FirstColumn,
                         value: item.SecondColumn
                     }
                 }))
             },
        error: function(XMLHttpRequest, textStatus, errorThrown) {
       alert(textStatus);
               }
 });
   },
    select: function(event, ui){
        event.preventDefault();
        $("#txtSearch" ).val(ui.item.label);
         },
 minLength:2
   });

Good luck.