I have a method named raise_alarm() which, show a message box based on jquery. But when I call this method from an event of a control(such as submit button) which is inside of Updatepanel, it isn't working. Related codes are below. How can I fix it?
Public Sub Raise_Alarm(ByVal p_Page As Page, ByVal p_Message As String, Optional ByVal p_IsError As Boolean = True)
Dim strScript As String
strScript = "$(function() { Mesaj('" & p_Message & "'); });" & ControlChars.NewLine
p_Page.ClientScript.RegisterStartupScript(p_Page.GetType(), "alert", strScript, True)
end sub
Private Sub dtlQuestion_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs) Handles dtlQuestion.ItemCommand
If Not User.Identity.IsAuthenticated Then
Raise_Alarm(Me, "Giriş Yapmadan Oy Veremezsiniz")
Exit Sub
End If
end sub
You have to use ScriptManager instead of p_Page.ClientScript.
EDIT : Example. I replaced p_Page.ClientScript by ScriptManager in your code.
Public Sub Raise_Alarm(ByVal p_Page As Page, ByVal p_Message As String, Optional ByVal p_IsError As Boolean = True)
Dim strScript As String
strScript = "$(function() { Mesaj('" & p_Message & "'); });" & ControlChars.NewLine
ScriptManager.RegisterStartupScript(p_Page.GetType(), "alert", strScript, True)
end sub
Private Sub dtlQuestion_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs) Handles dtlQuestion.ItemCommand
If Not User.Identity.IsAuthenticated Then
Raise_Alarm(Me, "Giriş Yapmadan Oy Veremezsiniz")
Exit Sub
End If
end sub
ClientScript is not ajax enabled, ScriptManager knows how to deal with partial postbacks. Please have a quick look at this article on msdn.
Related
i have three textboxes, one has 'quantity', the second has 'unit price' and the third has 'total'. what i want is to display the product of 'quantity' and 'unit price' into the 'total' textbox using the keyup trigger.
I am just beginning asp.net
Thanks
The focus of your application wont lie on the form itself so I would suggest putting the event in each textbox.
There is for sure a smoother solution but this worked for me:
Private Sub TextBoxQuantity_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBoxQuantity.KeyUp
If e.KeyCode = Keys.Up Then
TextBoxTotal.Text = TextBoxQuantity.Text & vbTab & TextBoxUnitPrice.Text
End If
End Sub
Private Sub TextBoxUnitPrice_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBoxUnitPrice.KeyUp
If e.KeyCode = Keys.Up Then
TextBoxTotal.Text = TextBoxQuantity.Text & vbTab & TextBoxUnitPrice.Text
End If
End Sub
Private Sub TextBoxTotal_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBoxTotal.KeyUp
If e.KeyCode = Keys.Up Then
TextBoxTotal.Text = TextBoxQuantity.Text & vbTab & TextBoxUnitPrice.Text
End If
End Sub
This is a wiki page on VB.net KeyPress-Event. Please read it to avoid further questions on this topic.
I'm working on a Login session through Visual Basic with asp.net. When the session timeout is complete and I click on another different page it gives me an error, "Object reference not set to an instance of an object." SessionState mode="InProc"
Here is the code that I used for the session:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Session("Username") Is Nothing Then
Label1.Text = "Welcome, " & Session("Username").ToString()
End If
End Sub
If Session("Username") IsNot Nothing Then
Label1.Text = "Welcome, " & Session("Username").ToString()
Else
Response.Redirect("~/Default.aspx")
End If
You need to check for if it's not null before you reference it. You were doing the opposite. You were checking to see if it's null, verifying it was, then referencing it. That's why you get a NullReferenceException. Basically all null reference exceptions are the same, you're trying to perform an operation on an object that is null.
Use a built in function which is exactly what you are looking for :
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsNothing(Session("Username")) Then
Label1.Text = "Welcome, " & Session("Username").ToString()
End If
End Sub
That's all :=)
Cheers
I'm new to asp.net (after programming for years in classic asp). I'm trying to build a page which adds something to a string.
My code is following:
default.aspx
<body>
<form id="form1" runat="server">
<div>
<p><asp:textbox id="tb" runat="server"></asp:textbox></p>
<asp:Panel ID="tbPanel" runat="server"></asp:Panel>
</div>
</form>
</body>
Code behind:
Partial Class demo_Default
Inherits System.Web.UI.Page
Public Property gesStr As String
Set(value As String)
ViewState("gesStr") = value
End Set
Get
Dim o As Object = ViewState("gesStr")
If o Is Nothing Then
Return ""
Else
Return o
End If
End Get
End Property
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim anzeigeStr As String = ""
If Page.IsPostBack Then
Else
gesStr = "1;"
End If
tb.Text = gesStr
Dim iButton As New Button
iButton.Text = "add"
iButton.CommandArgument = "1;"
AddHandler iButton.Click, AddressOf add
tbPanel.Controls.Add(iButton)
Me.anzeige()
End Sub
Private Sub add(ByVal sender As Object, ByVal e As EventArgs)
Dim myButton As Button = DirectCast(sender, Button)
Dim addString As String = myButton.CommandArgument
gesStr += addString
End Sub
Private Sub anzeige()
Dim gesArray As Array = Split(gesStr, ";")
For xLauf As Integer = 0 To UBound(gesArray) - 1
Dim anzLabel As New Label
anzLabel.Text = "<p>" & gesArray(xLauf) & "</p>"
tbPanel.Controls.Add(anzLabel)
Next
End Sub
End Class
The problem:
Pressing the button will cause a postBack, but the result of adding won't appear until the button is pressed a second time. The desired result is that the sub displays the correct array within the loop after the first time pressing the button.
Thank you so much for any help!
You need to call the function anzeige() and bind gesStr value to the textbox control each time the button is click. See the code below:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Page.IsPostBack Then
Else
gesStr = "1;"
End If
tb.Text = gesStr
Dim iButton As New Button
iButton.Text = "add"
iButton.CommandArgument = "1;"
iButton.CommandName = "1;"
AddHandler iButton.Click, AddressOf add
tbPanel.Controls.Add(iButton)
End Sub
Private Sub add(ByVal sender As Object, ByVal e As EventArgs)
Dim myButton As Button = DirectCast(sender, Button)
Dim addString As String = myButton.CommandArgument
gesStr += addString
anzeige()
End Sub
Private Sub anzeige()
Dim gesArray As Array = Split(gesStr, ";")
For xLauf As Integer = 0 To UBound(gesArray) - 1
Dim anzLabel As New Label
anzLabel.Text = "<p>" & gesArray(xLauf) & "</p>"
tbPanel.Controls.Add(anzLabel)
Next
'Bind gesStr value to the textbox control
tb.Text = gesStr
End Sub
I have a CheckBoxList on my page that isn't behaving very well.
The idea is that once the submit button on the form is clicked, the app should clear the database table of all rows pertaining to the specific user and then re-insert new ones based on the user's CheckBoxList selections.
The problem is that regardless of whether or not any (or all) items in the CheckBoxList are selected, the app keeps getting Selected = False.
Here's my code:
Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
loadRegions()
End Sub
Private Sub loadRegions()
Dim db As New Database
Dim sql As String = "select * from regions"
Dim dr As MySqlDataReader = db.execDB(sql, "Text", Nothing, "DataReader", False)
If dr.HasRows Then
cblRegion.DataSource = dr
cblRegion.DataTextField = "regionname"
cblRegion.DataValueField = "regionid"
cblRegion.DataBind()
End If
dr.Close()
End Sub
Protected Sub btnRegister_Click(sender As Object, e As System.EventArgs) Handles btnRegister.Click
' ============================================================
' There's more code in here, but it's irrelevant to this paste
' ============================================================
Dim sql As String = "delete from userregions where userid = " & lblUserID.Text & ";"
For i As Integer = 0 To cblRegion.Items.Count - 1
If cblRegion.Items(i).Selected Then
sql &= "insert into userregions (userid, regionid)" & _
"values(" & UserID & ", " & cblRegion.Items(i).Value & ")"
db.execDB(sql, "Text", Nothing, "None", False)
End If
Next
End Sub
For the record
I'm aware of the potential for SQL Injection here. I'll be going over to using Parameters as soon as I have the loop working.
Thanks for your time.
Any help will be greatly appreciated.
You only need to call loadRegions on the initial load and not on postbacks:
Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
loadRegions()
End If
End Sub
Otherwise you'll lose changed values and events are not triggered.
Add this line of copde "If IsPostBack Then Return" in Page_Load method.
Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
If IsPostBack Then Return
loadRegions()
End Sub
In page loaded, write the following:
If Not IsPostBack
loadRegions()
End If
I'm using ASP.net 4.0 VB :)
I am using a session variable to add a user entered code into the url of each page. I can get the code to show up at the end of the page's URL that my textbox is on, but what do I add to every page to make sure that the session stays at the end of every URL that person visits during their session? This is the code from the page that the user enters their user code.
Protected Sub IBTextBoxButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles IBTextBoxButton.Click
Session("IB") = IBTextBox.Text
Dim IB As String = Session("IB")
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
ProductID.Value = Request.QueryString("id")
If Session("IB") Is Nothing Then
tab4.Visible = "False"
Else
tab4.Visible = "True"
End If
End Sub
This is what I have in the page load of one of the other pages. What else do I add to make sure that variable is added to the URL of that page?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim IB As String
IB = Session("IB")
End Sub
string url = Request.Url.ToString();
string newUrl = url + url.Contains("?") ? "&" : "?" + "ib=" + Server.UrlEncode(IBTextBox.Text);
Response.Redirect(newUrl);
return;
The approach I might use would be to create a base page class that all of your pages can inherit. The base page would then inherit the System.Web.UI.Page.
Within your base page class, create a property for IB and also handle the page load event.
In that event, check if the QueryString has the IB parameter in it. If it does, set the property to the value in the parameter.
Private _IB As String
Public Property IB() As String
Get
Return _IB
End Get
Set(ByVal value As String)
_IB = value
End Set
End Property
Public Function GetIB(ByVal url As String) As String
If Not(_IB = String.Empty) Then
If (url.Contains("?")) Then
Return "&IB=" & _IB
Else
Return url & "?IB=" & _IB
End If
Else
Return url
End If
End Function
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not (String.IsNullOrEmpty(Request.QueryString("IB"))) Then
_IB = Request.QueryString("IB")
End If
End Sub
Finally in your markup you would need to place something like the following at the end of all of your links:
next page
I threw this code into the Master Page to make sure that every page knows whether or not the Session is there. Thanks for all the help everyone!
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Handles Me.Load
If Session("IB") Is Nothing Then
IBText.Visible = True
IBTextBox.Visible = True
IBTextBoxButton.Visible = True
Else
IBText.Visible = False
IBTextBox.Visible = False
IBTextBoxButton.Visible = False
lblIB.Visible = True
lblIB.Text = "Welcome, " + Session("First_Name") + " " + Session("Last_Name")
End If
End Sub