I need SQL Dependency change on a gridview displaying all rows that are changed or old data. Can anybody help me?
Here is my script:
<script>
$(function () {
var notify = $.connection.notificationsHub;
notify.client.displayNotification = function (msg) {
$("#newData").html(msg);
};
$.connection.hub.start();
});
</script> </head> <body>
<form id="form1" runat="server">
<div>
<asp:GridView id="newData" runat="server" AutoGenerateColumns="False">
</asp:GridView>
public void SendNotifications()
{
string message = string.Empty;
string conStr = ConfigurationManager.ConnectionStrings["TestDB"].ConnectionString;
using (SqlConnection connection = new SqlConnection(conStr))
{
string query = "SELECT [Message] FROM [dbo].[tb]";
using (SqlCommand command = new SqlCommand(query, connection))
{
command.Notification = null;
SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
connection.Open();
SqlDataReader reader = command.ExecuteReader();
if (reader.HasRows)
{
while (reader.Read())
{
message = reader.GetString(0);
}
}
}
}
NotificationsHub nHub = new NotificationsHub();
nHub.NotifyAllClients(message);
}
private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
{
if (e.Type == SqlNotificationType.Change)
{
SendNotifications();
}
}
Related
I am struggling a bit to populate my dropdown list, can anybody tell me where I am going wrong?
ASPX CODE it keeps looping after getting the connection string - back into the connection string method.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindDropDownList();
}
}
private string GetConnectionString()
{
using (DataManager dmgr = new DataManager())
{
dmgr.Connect(ConfigurationManager.AppSettings["ProductionKey"]);
return BindDropDownList();
}
}
public string BindDropDownList()
{
DataTable dt = new DataTable();
SqlConnection connection = new SqlConnection(GetConnectionString());
try
{
connection.Open();
string sqlStatement = "SELECT * FROM Itemseriesmaster";
SqlCommand sqlCmd = new SqlCommand(sqlStatement, connection);
SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCmd);
sqlDa.Fill(dt);
if (dt.Rows.Count > 0)
{
DropDownList1.DataSource = dt;
DropDownList1.DataTextField = "Description"; // the items to be displayed in the list items
DropDownList1.DataValueField = "ID"; // the id of the items displayed
DropDownList1.DataBind();
}
}
catch (SqlException ex)
{
string msg = "Fetch Error:";
msg += ex.Message;
throw new Exception(msg);
}
finally
{
connection.Close();
}
return AppRelativeTemplateSourceDirectory;
}
DataManager Code - where the code calls into
public DataSet ItemSeriesMaster(int id, string description)
{
object[] args = new object[2] { id, description };
return CallSp(MethodBase.GetCurrentMethod(), args) as DataSet; // i know this is not an sp call.. just testing
}
}
}
I am trying to go to my database and bring out the list.
I want to create a grid and automatic update it, when data changes in the database. It works with a simple table control.
public partial class index : System.Web.UI.Page
{
static string connectionString = #"Data Source=*******;initial catalog=Test;persist security info=True; Integrated Security=SSPI;";
protected void Page_Load(object sender, EventArgs e)
{
}
[WebMethod]
public static IEnumerable<Person> GetData()
{
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
using (SqlCommand command = new SqlCommand(#"SELECT [Id],[Name] FROM [dbo].[Persons]", connection))
{
command.Notification = null;
SqlDependency.Start(connectionString);
SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(Dependency_OnChange);
if (connection.State == ConnectionState.Closed)
connection.Open();
using (var reader = command.ExecuteReader())
return reader.Cast<IDataRecord>()
.Select(x => new Person(x.GetInt32(0), x.GetString(1))).ToList();
}
}
}
private static void Dependency_OnChange(object sender, SqlNotificationEventArgs e)
{
MyHub.Show();
}
public void FillGrid()
{
List<Person> persons = new List<Person>();
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
using (SqlCommand command = new SqlCommand(#"SELECT [Id],[Name] FROM [dbo].[Persons]", connection))
{
if (connection.State == ConnectionState.Closed)
connection.Open();
using (SqlDataReader rdr = command.ExecuteReader())
{
while (rdr.Read())
{
var id = rdr.GetInt32(0);
var name = rdr.GetString(1);
persons.Add(new Person(id, name));
}
}
}
}
grid.DataSource = persons;
grid.DataBind();
}
}
public class MyHub : Hub
{
public static void Show()
{
IHubContext context = GlobalHost.ConnectionManager.GetHubContext<MyHub>();
context.Clients.All.displayStatus();
}
}
And the apsx Page :
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="Scripts/jquery-1.6.4.min.js"></script>
<script src="Scripts/jquery.signalR-2.2.2.min.js"></script>
<script src="signalr/hubs"></script>
<script type="text/javascript">
$(function () {
// Proxy created on the fly
var job = $.connection.myHub;
// Declare a function on the job hub so the server can invoke it
job.client.displayStatus = function () {
getData();
};
// Start the connection
$.connection.hub.start();
getData();
});
function getData()
{
var $tbl = $('#tbl');
$.ajax({
url: '/index.aspx/GetData',
contentType: 'application/json;charset=utf-8',
datatype: 'json',
type: 'POST',
success: function (data) {
if (data.d.length > 0) {
var newdata = data.d;
$tbl.empty();
$tbl.append(' <tr><th>ID</th><th>Name</th></tr>');
var rows = [];
for (var i = 0; i < newdata.length; i++) {
rows.push(' <tr><td>' + newdata[i].Id + '</td><td>' + newdata[i].Name + '</td><td></tr>');
}
$tbl.append(rows.join(''));
}
}
});
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<table id="tbl"></table>
<dx:ASPxGridView ID="grid" runat="server"></dx:ASPxGridView>
</div>
</form>
</body>
</html>
However I want to use a Devepress Aspxgridview. The Devexpress Site states they don't support SignalR. However since the Javascript function is triggered when data changes in the database, is it possible somehow to force the client to get the data from the server? Force a postback and/or call the FillGrid method? ( To create the grid from js is not possible since the AspxgridView Control is much more complicated).
SOURCE: https://www.youtube.com/watch?v=30m-7wpmbrc
Although SignalR is not supported out of the box, it should be possible to manually notify the server side about the update using the existing API. You can send a callback to the server using the ASPxClientGridView.PerformCallback method, and handle the server side ASPxGridView.CustomCallback event to reload data from the SQL server.
I'm deleting a single database record from a listview and after deleting I try to navigate in my listview using listView1.selectedindex property, but I have noticed that it highlights the incorrect record (for example I set listView1.selectedindex to 1 but it displays a record which has index 0) . What is wrong? Please help!
protected void deleteButton_Click(object sender, EventArgs e)
{
int id = int.Parse(((Label)ListView1.Items[ListView1.SelectedIndex].FindControl("idLabel")).Text);
using (SqlConnection conn = new SqlConnection(connStr))
{
string Sql = "delete from Employee where id = #id";
conn.Open();
using (SqlCommand dCmd = new SqlCommand(Sql, conn))
{
dCmd.Parameters.AddWithValue("#id", id);
dCmd.ExecuteNonQuery();
}
conn.Close();
}
BindDataFromBaseToListView();
}
BindDataFromBaseToListView method looks so:
private void BindDataFromBaseToListView()
{
using (SqlConnection conn = new SqlConnection(connStr))
{
conn.Open();
using (SqlDataAdapter dAd = new SqlDataAdapter("select * from Employee", conn))
{
DataTable dTable = new DataTable();
dAd.Fill(dTable);
ListView1.DataSourceID = null;
ListView1.DataSource = dTable;
ListView1.DataBind();
}
conn.Close();
}
Instead of using deleteButton_Click event you could use your ListView's OnItemCommand event to get the selected row values and delete the item that you want like the code below:
protected void ListView1_ItemCommand(object sender, ListViewCommandEventArgs e)
{
if (e.CommandName == "delete")
{
int id = 0;
if(int.TryParse((e.Item.FindControl("idLabel") as Label).Text, out id))
{
using (SqlConnection conn = new SqlConnection(connStr))
{
string Sql = "delete from Employee where id = #id";
conn.Open();
using (SqlCommand dCmd = new SqlCommand(Sql, conn))
{
dCmd.Parameters.AddWithValue("#id", id);
dCmd.ExecuteNonQuery();
}
conn.Close();
}
BindDataFromBaseToListView();
}
}
}
And on your control's element will look like this:
<asp:ListView ID="ListView1" runat="server" OnItemCommand="ListView1_ItemCommand" .. >
...
<ItemTemplate>
<asp:Button runat="server" CommandName="delete" Text="Delete" ID="DeleteButton" />
...
Let me know if you still have issue with it.
I am trying to check if the username exists or not . I am using XMLHTTPREqUEST object in the html page and sending user name and password values to Default aspx page.But when I exacute the code .Nothing happens.I mean There is no exception message or anyting after debugging I have noticed that connection state open but datareader's hasRows property returns false.I am sure I am able to pass query string values into variables . And What am i missing out Can you plase help
protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["ka"] != null && Request.QueryString["pass"] != null)
{
string username = Request.QueryString["ka"];
string pass = Request.QueryString["pass"];
SqlConnection con = new SqlConnection("server=.\\sqlexpress;database=Projects;UID=sa;Password=1234");
if (con.State == ConnectionState.Closed) {
con.Open();
SqlCommand cmd = new SqlCommand("select * from userstable where username=#name and pass=#pass", con);
cmd.Parameters.AddWithValue("#name", username);
cmd.Parameters.AddWithValue("#pass", pass);
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)
{
Response.Write("exist");
}
else
{
Response.Write("Doesntexist");
}
con.Close();
}
}
Response.Close();
}
this is Htmlpage
<script src="Scripts/jquery-2.1.1.js"></script>
<script type="text/javascript">
function createXHR() {
var xhr;
try {
xhr = new XMLHttpRequest();
} catch (e) {
}
return xhr;
}
function signIn() {
var xhr = createXHR();
var username=$('#txtusername').val();
var pass=$('#txtpass').val()
xhr.onreadystatechange=function(){
if(xhr!=null){
if(xhr.readyState==4){
if(xhr.status>=200 && xhr.status<300){
var v = $('#result').html(xhr.responseText);
if (v == "exist") {
$('#result').html("Done");
}
else if (v == "Doesntexist") {
$('#result').html("Error");
}
else{
$('#result').html(v);
}
}
}
}
else{
$('#result').html("Error");
}
}
xhr.open("GET", "Default.aspx?ka='" + username + "&pass=" + pass, true);
xhr.send(null);
}
</script>
</head>
<body>
<input id="txtusername" type="text" name="txtusername"/><br />
<input id="txtpass" type="text" name="txtpass"/><br />
<input id="Button1" type="button" value="signin" onclick="signIn();" /><br />
<div id="result" ></div>
</body>
I am trying to display a grid if the user entered register number exists in database, if the register number does not exists this means that I need to display one label also.i am a new one in asp.net,so please help me.
Here is my code below.
public DataTable madhrasaViewByRegNo(string viewByNo)
{
try
{
madhrasaInfo infomadhrasa = new madhrasaInfo();
object decobj = new object();
if (sqlcon.State == ConnectionState.Closed)
{
sqlcon.Open();
}
SqlCommand sqlcmd = new SqlCommand("madhrasaViewByRegNo", sqlcon);
sqlcmd.CommandType = CommandType.StoredProcedure;
sqlcmd.Parameters.Add("#regNo", SqlDbType.VarChar).Value = viewByNo;
decobj = sqlcmd.ExecuteNonQuery();
if (decobj == null)
{
decStuId = decimal.Parse(decobj.ToString());
}
else
{
DataTable dtbClass = new DataTable();
SqlDataAdapter sqlda = new SqlDataAdapter("madhrasaViewByRegNo", sqlcon);
sqlda.SelectCommand.CommandType = CommandType.StoredProcedure;
sqlda.SelectCommand.Parameters.Add("#regNo", SqlDbType.VarChar).Value = viewByNo;
sqlda.Fill(dtbClass);
return dtbClass;
}
}
catch (Exception)
{
throw;
}
return null;
}
public void gridfillByNo()
{
madhrasaSp spMadhrasa = new madhrasaSp();
DataTable dtbl = new DataTable();
dtbl = spMadhrasa.madhrasaViewByRegNo(TextBox2.Text);
gvstuResult.DataSource = dtbl;
gvstuResult.DataBind();
}
public void regSearch()
{
madhrasaSp spmadhrasa = new madhrasaSp();
spmadhrasa.madhrasaViewByRegNo(TextBox2.Text);
if (madhrasaSp.decStuId > 0)
{
gridfillByNo();
MultiView1.ActiveViewIndex = 1;
}
else
{
MultiView1.ActiveViewIndex = 0;
Label1.Visible = true;
Label1.Text = "Invalid Register Number";
}
}
protected void Button2_Click(object sender, EventArgs e)
{
regSearch();
}
You Dont you just set the grid view's EmptyDataText to 'Reg No Dosent exist'. It will solve your ploblem.
<asp:GridView ID="GridView1" runat="server" EmptyDataText="register number not available">
</asp:GridView>