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ASP.net, c#, website, dropdownlist, Not calling browserLink function[Answered]
1 reply
Last post Apr 09, 2019 02:14 AM by Ackerly Xu
Last post Apr 09, 2019 02:14 AM by Ackerly Xu
Member
18 Points
50 Posts
ASP.net, c#, website, dropdownlist, Not calling browserLink function
Apr 08, 2019 07:38 PM|Tom4IT|LINK
When I run this code on my desktop machine the dropdownlist works. When I run the code on the test server the page doesn't refresh with the result of the change in the dropdownlist on change function. When I step through in the visual studio debugger the difference I can see is that the browserLink function doesn't get called after this linke <select name="DropDownList1" id="DropDownList1" onchange="changeCourse(event)">. I have active script enabled in the browser. Is there a javascript library I need to install on the test machine or some script I need to enable.
I looked up browserLink on msdn and see that it is a .net core function. I see that on my desktop I have .net core 2.0 development tools, and .net core 1.0 - 1.1 development tools for web installed and I don't have those installed on the test server. But those options are not in the test server Server Manager Select features. Could that be the problem?
courses.forEach(function (course) {
var value = course.RecordID + '|' + course.CourseCode + '|' + course.Title;
html += '<option value="' + value + '">' + course.Title + '</option>';
instructor aspx listing
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="instructorcourse.aspx.cs" Inherits="updatecourses" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head3" runat="server">
<title>On Grounds</title>
<style type="text/css">
.auto-style1 {
width: 30px;
}
.auto-style2 {
width: 132px;
}
.auto-style5 {
width: 24px;
}
.auto-style7 {
width: 140px;
height: 26px;
}
.auto-style8 {
width: 24px;
height: 26px;
}
.auto-style9 {
width: 273px;
}
.auto-style10 {
width: 123px;
}
.auto-style11 {
width: 123px;
height: 26px;
}
.auto-style12 {
/*width: 140px;*/
}
</style>
</head>
<body>
<%--<script>JavaScript is Active</script>
<noscript>JavaScript is Disabled</noscript>--%>
<form id="form3" runat="server">
<h2 class="auto-style9">
<asp:Image ID="Image1" runat="server" Height="103px" Width="216px" ImageUrl="~/headerLogo.png" />
</h2>
<h2>Attendance</h2>
<h2>Intructor - Next Course</h2>
<table>
<tr>
<td class="auto-style10">Insctructor ID:</td>
<td class="auto-style12">
<asp:TextBox ID="txtInstructorID" runat="server" Enabled="False"></asp:TextBox></td>
<td class="auto-style5"></td>
</tr>
<tr>
<td class="auto-style11">Instructor Name:</td>
<td class="auto-style7">
<asp:TextBox ID="txtInstructorName" runat="server" Enabled="False"></asp:TextBox></td>
<td class="auto-style8"></td>
</tr>
<tr>
<td class="auto-style10">Course Code:</td>
<td class="auto-style12">
<asp:TextBox ID="txtCourseCode" runat="server" Enabled="False"></asp:TextBox></td>
<td class="auto-style5"> </td>
</tr>
<tr>
<td class="auto-style10">Course Title:</td>
<td class="auto-style12">
<asp:TextBox ID="txtCourseTitle" runat="server" Enabled="False"></asp:TextBox></td>
<td class="auto-style5">
<select name="DropDownList1" id="DropDownList1" onchange="changeCourse(event)">
</select> <%--on change, populates text boxes with result, then should call browserLink function, not calling now--%>
</select>
</td>
</tr>
<tr>
<td class="auto-style10">Course StartTime:</td>
<td class="auto-style12">
<asp:TextBox ID="txtStartTime" runat="server" Enabled="False"></asp:TextBox></td>
</tr>
<tr>
<td class="auto-style10">Attendance Code: </td>
<td class="auto-style12">
<asp:TextBox ID="txtAttendanceCode" runat="server" ToolTip="Use the System Generated Random Code or click the Code Button to Generate a New Code, Youn can alsto Enter Your Own Code!"></asp:TextBox>
</td>
<td class="auto-style5">
<asp:Button ID="btnGenerateCode" runat="server" OnClick="BtnGenerateCode_Click" Text="Code" />
</td>
</tr>
</table>
<br />
<asp:Button ID="btnAdd" runat="server" Text="Save Code" OnClick="btnAdd_Click" />
<br />
<br />
<asp:Button ID="btnHelp" runat="server" Text="?" ToolTip="Instructions/Notes: You can use the system generated code or create your own. We recommend that it is user-friendly. All codes are unique to this course. Click Save Code to capture the attendance code for this course session. Students must be in this class and on the Parker U wireless network to post their attendance. If students do not have a smartphone or laptop, you can allow them to log in to MyParker at the podium. " />
<br />
<br />
<asp:Label ID="lblMsg" runat="server" EnableViewState="False"></asp:Label>
<br />
<asp:Panel ID="Panel1" runat="server" Width="267px">
<%--<br />
Instructions/Notes:
<br />
-You can use the system generated code or create your own. We recommend that it is user-friendly.
<br />
-All codes are unique to this course.
<br />
-Click Save Code to capture the attendance code for this course session.
<br />
-Students must be in this class and on the Parker U wireless network to post their attendance.
<br />
-If students do not have a smartphone or laptop, you can allow them to log in to MyParker at the podium.--%>
</asp:Panel>
<asp:Label ID="Label2" runat="server" EnableViewState="False"></asp:Label>
<br />
<br />
<table>
<tr>
<%--<td class="auto-style4">Record ID: </td>--%>
<td class="auto-style2">
<asp:TextBox ID="txtRecordID" runat="server" Enabled="False" Visible="False"></asp:TextBox>
</td>
<td class="auto-style1">
<%-- will select next course on form load, by hostid, will go in form load</tr>--%>
</table>
<br />
<br />
</form>
<script type="text/javascript">
function load() {
var xhttp = new XMLHttpRequest();
xhttp.open('post', 'instructorcourse.aspx/GetCourseTitles', true);
xhttp.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
xhttp.setRequestHeader('Content-Type', 'application/json');
xhttp.onreadystatechange = function () {
if (xhttp.readyState == XMLHttpRequest.DONE && xhttp.status == 200) {
var $titlesDropDown = document.getElementById('DropDownList1'),
courses = JSON.parse(JSON.parse(this.responseText).d),
html = '';
courses.forEach(function (course) {
var value = course.RecordID + '|' + course.CourseCode + '|' + course.Title;
html += '<option value="' + value + '">' + course.Title + '</option>';
});
$titlesDropDown.innerHTML = html;
}
};
xhttp.send(JSON.stringify({ instructorId: '<%=txtInstructorID.Text%>' }));
}
document.addEventListener('DOMContentLoaded', load);
function changeCourse(e) {
var temp = e.target.value.split('|'),
recordID = parseInt(temp[0]),
courseCode = temp[1],
title = temp[2];
document.getElementById('<%=nameof(txtInstructorID)%>').value = recordID;
document.getElementById('<%=nameof(txtCourseCode)%>').value = courseCode;
document.getElementById('<%=nameof(txtCourseTitle)%>').value = title;
}
</script>
</body>
</html>
instructor cs script
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Web;
using System.Web.Security;
using System.Web.Services;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class updatecourses : System.Web.UI.Page
{
protected void Page_LoadComplete(object sender, EventArgs e)
{
//MessageBox.Show("You are in the Form.Shown event.");
{
SqlConnection con = new SqlConnection(Database.ConnectionString);
try
{
var returnUrl = Request.Params["ReturnUrl"];
var hostID = Request.Params["HostID"];
if (string.IsNullOrWhiteSpace(hostID))
{
if (!string.IsNullOrWhiteSpace(returnUrl))
Response.Redirect(returnUrl);
throw new Exception("Variable \"HostID\" not found in query params");
}
con.Open();
var cmd = new SqlCommand("select * from OnGroundsWebSite.dbo.courses where InstructorID = @hostId", con);
//var hostID = Request.Params["HostID"];
cmd.Parameters.AddWithValue("hostId", hostID);
var dr = cmd.ExecuteReader();
if (!dr.Read())
Response.Redirect($"studentcourse.aspx?hostId={hostID}"); // won't need to redirect, instructor will click link on web site for Faculty (Instrcutor) or student
dr.Close();
//string accountId = Request.Cookies["AccountIdentifier"].Value;
//if (string.IsNullOrWhiteSpace(accountId))
// Response.Redirect("/enteremail.aspx");
//var query = string.IsNullOrWhiteSpace(txtRecordID.Text) ? "select * from courses where InstructorID = @instructorId" : "select * from courses where InstructorID = @instructorId and RecordID = @RecordID"; //---- should select from schedule
//var query = "select * from courses where InstructorID = @instructorId"; //need to join to get course and account info
var query = "select * from courses where InstructorID = @hostID"; //need to join to get course and account info
//cmd.Parameters.AddWithValue("HostID", "Int");
cmd = new SqlCommand(query, con);
//cmd.Parameters.AddWithValue("instructorId", accountId);
//cmd.Parameters.AddWithValue("instructorId", hostID);
cmd.Parameters.AddWithValue("HostID", hostID);
cmd.Parameters.AddWithValue("RecordID", txtRecordID.Text);
cmd.Parameters.AddWithValue("now", DateTime.Now);
//cmd.Parameters.AddWithValue("Now", DateTime.Now);
dr = cmd.ExecuteReader();
if (dr.Read())
{
// display data in textboxes
txtRecordID.Text = dr["RecordID"].ToString();
txtInstructorID.Text = dr["InstructorID"].ToString();
//txtInstructorID.Text = dr["HostID"].ToString();
txtInstructorName.Text = dr["InstructorName"].ToString();
txtCourseCode.Text = dr["CourseCode"].ToString();
txtCourseTitle.Text = dr["CourseTitle"].ToString();
//txtStartTime.Text = dr["StartTime"].ToString();
txtAttendanceCode.Text = dr["AttendanceCode"].ToString();
//btnUpdate.Enabled = true;
//btnUpdate.Visible = true;
}
else
{
lblMsg.Text = "You do not have a class in the next hour.";
//btnUpdate.Enabled = false;
//btnUpdate.Visible = false;
}
dr.Close();
}
catch (Exception ex)
//catch (Exception)
{
lblMsg.Text = "Error --> " + ex.Message;
}
finally
{
con.Close();
}
if (string.IsNullOrWhiteSpace(txtAttendanceCode.Text))
{
//string alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
//string small_alphabets = "abcdefghijklmnopqrstuvwxyz";
string numbers = "1234567890";
string characters = numbers;
int length = 5;
string otp = string.Empty;
for (int i = 0; i < length; i++)
{
string character = string.Empty;
do
{
int index = new Random().Next(0, 5);
character = characters.ToCharArray()[index].ToString();
} while (otp.IndexOf(character) != -1);
otp += character;
}
txtAttendanceCode.Text = otp;
}
}
}
protected void BtnGenerateCode_Click(object sender, EventArgs e)
{
{
//string alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
//string small_alphabets = "abcdefghijklmnopqrstuvwxyz";
string numbers = "1234567890";
string characters = numbers;
int length = 5;
string otp = string.Empty;
for (int i = 0; i < length; i++)
{
string character = string.Empty;
do
{
int index = new Random().Next(0, 5);
character = characters.ToCharArray()[index].ToString();
} while (otp.IndexOf(character) != -1);
otp += character;
}
txtAttendanceCode.Text = otp;
}
}
[WebMethod]
public static string GetCourseTitles(string instructorId)
{
var result = new List<dynamic>();
SqlConnection con = new SqlConnection(Database.ConnectionString);
try
{
con.Open();
//var cmd = new SqlCommand("select RecordID, CourseCode, CourseTitle from courses where InstructorID = @instructorId", con);
var cmd = new SqlCommand("select InstructorID, CourseCode, CourseTitle from courses where InstructorID = @instructorId", con);
cmd.Parameters.AddWithValue("instructorId", instructorId);
var reader = cmd.ExecuteReader();
while (reader.Read()) //reader, reading through results
{
result.Add(new
{
//RecordID = reader.GetInt32(1),
//RecordID = reader.GetInt64(1),
//HostID = reader.GetString(0), //runs with GetString, but should be RecordID
RecordID = reader.GetString(0), //InstructorID, getting by column id, assigning to variable for json function
//RecordID = reader.GetGuid(0),
//RecordID = reader.GetGuid(0),
CourseCode = reader.GetString(1),
Title = reader.GetString(2)
});
}
reader.Close();
}
catch
{
}
finally
{
con.Close();
}
return JsonConvert.SerializeObject(result);
}
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnAdd_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(Database.ConnectionString);
try
{
con.Open(); //
SqlCommand cmd = new SqlCommand("insert into OnGroundsWebSite.dbo.InstructorCourse(RecordID,InstructorID,CourseID,CourseCode,CourseTitle,AttendanceCode) values(@RecordID,@InstructorID,@CourseID,@CourseCode,@CourseTitle,@AttendanceCode)", con);
//InstructorCourse, will have one record for instructors course
//attendance is Students attendance for course, multiple student records for InstructorCourse
//If instructor save and browse to page again, should it show attendance code saved, now shows new code
//if try to save, shows key violation
cmd.Parameters.AddWithValue("@RecordID", txtRecordID.Text);
cmd.Parameters.AddWithValue("@InstructorID", txtInstructorID.Text);
cmd.Parameters.AddWithValue("@CourseID", txtRecordID.Text);
cmd.Parameters.AddWithValue("@CourseCode", txtCourseCode.Text);
cmd.Parameters.AddWithValue("@CourseTitle", txtCourseTitle.Text);
cmd.Parameters.AddWithValue("@AttendanceCode", txtAttendanceCode.Text);
int count = cmd.ExecuteNonQuery();
if (count == 1)
//lblMsg.Text = "Attendance [" + txtCourseTitle.Text + "] has been added!";
lblMsg.Text = "Attendance Code [" + txtCourseCode.Text + "] has been recorded!";
else
lblMsg.Text = "Could not add Attendance!";
}
catch (Exception ex)
{
lblMsg.Text = "Error --> " + ex.Message;
}
finally
{
con.Close();
}
}
}
Contributor
3500 Points
1300 Posts
Re: ASP.net, c#, website, dropdownlist, Not calling browserLink function
Apr 09, 2019 02:14 AM|Ackerly Xu|LINK
Hi Tom4IT ,
Not clear about what browserLink function means.
From your code, you bind a change event on a select.
It seems you have one more </select> in your html.
And you fill the select with load method.
In your test server , have you seen the dropdownlist is filled?
And have you seen the changeCourse is called?
Since you are writing javascript code , I suggest you debug using F12 developer tool to check if there is any error message in your console in client and debug your javascript code.
https://developers.google.com/web/tools/chrome-devtools/javascript/
Best regards,
Ackerly Xu
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