I'm having a problem with ASP.net redirection.
The Copy() method below is called from a javascript button in a grid with ajax and it works fine. It redirects to the Create action of the controller.
<AcceptVerbs(HttpVerbs.Post)> _
Sub Copy(ByVal noDemande As Integer)
Response.Redirect("/DemandeDeMontage/Create/" & noDemande)
End Sub
The Create action is a page that lets me edit the fields before saving them to the database. When an Id is passed, the fields will be pre-filled with another record's info (copied info).
<AcceptVerbs(HttpVerbs.Get)> _
Function Create(Optional ByVal id As Integer? = Nothing) As ActionResult
If (id Is Nothing) Then
Dim dmd As New DEMND_MONTG
Return View("Edit", dmd)
Else
Dim dmd As ODCT0124_DEMND_MONTG = _dmdMontRep.getDmdById(id)
dmd.CO_STAT = ModuleCommon.Status.AwaitingSave
Return View("Edit", dmd)
End If
End Function
There are no errors in the code above.
When debugging, everything seems to work. The Copy action is called, then Create, and then I can step through the HTML code of the Edit page without any errors.
However, the page will not change! It's like I'm not redirected at all. The edit page is not shown and I'm stuck on the page displaying the grid with all records I can copy.
Can someone explain why the edit page is not shown? Is there something really obvious I am not seeing?
That was a silly error on my part.
The Copy action was called via AJAX, but I forgot to specify what to do with the html returned from the action.
I'm using window.location = "/DemandeDeMontage/Copy/" + id now instead.
Related
I have an application in ASP.Net Ajax. I want to open it via a browsercontrol from a winform, and I wish to access a variable (username) that the user used to log in to the webform with. On load I would like to read that username and perform the rest of my webpage code on that browsercontrol using that username.
My ASP.Net Ajax has been published to a internal web server and the browsercontrol loads that IP address.
Is there any way to achieve this at all?
EDIT:
I have discovered the javascript extension: window.external
And I can call a C# procedure from the webpage using javascript with it, which is a start, but I need to retrieve a varaible from c# - this is where the problem comes in. I have tried the
var name = function window.external.GetGlobalVariable(MyGlobalProcedure, "Cannot Get Value");
But javascript error says the method cannot be applied to the object.
Your answer should be as follows:
Public Class Form1
Dim GlobalVar As String = "Your Name"
Dim YourBrowser As New WebBrowser
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
YourBrowser.Url = New Uri("Your URL address")
AddHandler YourBrowser.DocumentCompleted, AddressOf PageLoadComplete
End Sub
'The invokescript will only work once the HTML has finished loading itself into your WebBrowser
Sub PageLoadComplete()
'Must declare the string inside an array as the invokescript only allows an object to be sent
Dim VarToSend As String() = {GlobalVar}
YourBrowser.Document.InvokeScript("yourJavascriptfunction", VarToSend)
End Sub
The javascript section should look as follows:
<script type="text/javascript" language="javascript">
function userNameSet(name) {
$(document).ready(function() {
//variable now exists inside your WebBrowser client and can be used accordingly now
alert(name);
});
}
</script>
References for answer: http://www.dotnetcurry.com/showarticle.aspx?ID=194
"Store that name in a session variable and access the session in your ajax call"
In your ASP.Net application create a hidden field (or if it's somewhere on the UI in some control that works also). Put the username or whatever information you want to share into that field.
From your WinForms program you can request that field through the WebBrowser control like this:
MessageBox.Show(WebBrowser1.Document.GetElementById("txtUsername").GetAttribute("value"))
The above assumes you have some HTML element called txtUsername with the value attribute set.
I'm writing an ASP web application with VB back-end. What I'd like to do is generate a url and display this in control on the page. For example if I have a label and a button on the form. The label is blank. When the button is clicked the following code fires:
Protected Sub btnGenerate_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnGenerate.Click
label1.Text = "Hello"
End Sub
What I'd like to have is a url that would point to my ASP Page with the words "Hello" in the label. Is this possible?
You could do the following:
{siteaddress}/aspxpage.aspx?label=hello
then in you aspx page do something like:
<asp:label runat="server" id="yourLabelId" text='<%=Request.QueryString("label")%>' />
Or in the Page_Load:
yourLabelId.Text = Request.QueryString("label")
I would recommend validating the data before just writing it into the page.
Pass the text in query string e.g. suppose relative path of the page is /pagename.aspx , you can pass the query string as per given example below:
/pagename.aspx?text=hello
in c# write following code in Page_Load event
//You don't have to check the url all the time , so just check it if page is not posting back (first time after user visits the page and ignore all other same page post backs. Label can maintain its control state (text value) after every postback, so assign it only once to increase performance
if (!IsPostBack)
{
//Check if query string is provided or not , if it is not provided take some default text, I am taking empty string as default text.
string givenText = (Request.QueryString["text"] == null)?"":Request.QueryString["text"];
label1.Text = givenText;
}
You can also create a property for text given through query string and default text.
I have the following steps in my webpage
1) User Logs in and I set the following session variables
Session("userName") = reader_login("useremail").ToString()
Session("userId") = reader_login("user_ID").ToString()
Session("firstName") = reader_login("firstName").ToString()
2) Now on my logged in VB.NET templates I reference a MasterPage called LoggedIn.Master. In Which I added the following method to check for the above null session variables. And if they null to redirect back to login page.
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
'#Check that User is Logged in, if not redirect to login page
If (Session("userId") Is Nothing) Or (Session("userName") Is Nothing) Or (Session("firstName") Is Nothing) Then
Response.Redirect(ConfigurationManager.AppSettings("site_base_url").ToString & "login/", False)
End If
3) Now my question is if I want to use any above 3 Session variables in different .net templates or usercontrols referencing the above master page do i need to AGAIN add the check
If (Session("userId") Is Nothing) Or (Session("userName") Is Nothing) Or (Session("firstName") Is Nothing) Then
Response.Redirect(ConfigurationManager.AppSettings("site_base_url").ToString & "login/", False)
End If
In the respective pages or will the check in master page do. Because at the moment i.e. if in a usercontrol I attempt to do i.e.
customerName.Text = Session("userName").ToString()
or
Response.Write(Session("userName").ToString())
I am getting the error
Object reference not set to an instance of an object.
customerName.Text = Session("userName").ToString()
You can write a wrapper around the Session to handle null values and just call the wrapper when you access the items:
Public Class SessionWrapper
Public Shared ReadOnly Property Item()
'Access session here and check for nothing
End Property
End Class
And use it like this
SessionWrapper.Item("itemName")
In answer to your question - as long as the masterpage checks the session and redirects before all your controls and page code make a reference to Session, you should be fine.
You were using OnInit() which seems reasonable, but see this article for a good understanding of the timing of events.
Incidentally, I strongly discourage the use of ad-hoc calls to Session in your page and control code. Instead, I recommend you create a static SessionManager class that does the Session referencing for you. That way, you get to benefit from strong typing, and won't be able to accidentally make hard-to-debug 'session key' typos in your code like Session["FiirstName"]. Also, you can incorporate your null-session check right into the call for the session value:
EXAMPLE (in C#, sorry!)
public static class SessionManager
{
private static void EnsureUserId()
{
if (Session["userId"] == null)
{
Response.Redirect("YourLogin.aspx", false);
}
}
public static string FirstName
{
get
{
EnsureUserId();
if (Session["firstName"] == null)
Session["firstName"] = "";
return (string)Session["firstName"];
}
set
{
Session["firstName"] = value;
}
}
}
You can create an http module that asks about the session objects and if they are null, it will redirect to the login page and by developing this http module, in each page request the module will do the check and then you can use it normally without checking.
A better way to handle this would be to add a base class for all controls that require this session variables to be present. You can then add properties to wrap access to the session and other cool stuff and the check will work even if the controls are used with a different master page.
I have created an VB.NET page to record views for ads and will call page from img src.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Dim insert_number As Integer = 0
Dim ad_id As Integer = 0
If Request.QueryString("adid") Is Nothing Then
ad_id = 0
Else
If Not Integer.TryParse(Request.QueryString("adid"), ad_id) Then
ad_id = 0
End If
End If
Dim connectStr As String = System.Configuration.ConfigurationManager.AppSettings("connectStr").ToString()
Dim myconnection As SqlConnection = New SqlConnection(connectStr)
Dim mySqlCommand As SqlCommand
myconnection.Open()
Try
mySqlCommand = New SqlCommand("sp_record", myconnection)
mySqlCommand.CommandType = CommandType.StoredProcedure
mySqlCommand.Parameters.AddWithValue("#record_id", ad_id)
insert_number = mySqlCommand.ExecuteNonQuery()
Catch ex As Exception
End Try
myconnection.Close()
Dim oBitmap As Bitmap = New Bitmap(1, 1)
Dim oGraphic As Graphics = Graphics.FromImage(oBitmap)
oGraphic.DrawLine(New Pen(Color.Red), 0, 0, 1, 1)
'Response.Clear()
Response.ContentType = "image/gif"
oBitmap.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif)
'oBitmap.Dispose()
'oGraphic.Dispose()
End Sub
Unless I comment oBitmap.Save line, the code runs twice and it makes two inserts (store prcoedure runs twice) to Database.
I have tried AutoEventWireup = "true" and "false" at #PAGE. "true" runs code twice, "false" did not do anything (no error) and did not give any output as well.
I have also tried following version of creating 1pixel image output but it did run twice as well (it requires aspcompat=true in #PAGE part):
'Response.ContentType = "image/gif"
'Dim objStream As Object
'objStream = Server.CreateObject("ADODB.Stream")
'objStream.open()
'objStream.type = 1
'objStream.loadfromfile("c:\1pixel.gif")
'Response.BinaryWrite(objStream.read)
Any ideas are welcome.
You may want to do an onload function for the image to see why it's being called a second time. I'm guessing that it's getting loaded somewhere in the preload and then being called (.Save) during the page load as well and that's why you're seeing the double entry.
If you are trying to get unique page loads, you may want to try putting the oBitmap.Save line within a check for postback like this within the page load:
If Page.IsPostback = False Then
'Bitmap Code Here
End If
And see if that fixes it for you.
If you're loading data from a database, you'll want to make sure that it also is within that PostBack check (because a. you're loading the data twice and b. it can cause these double postbacks in some circumstances).
Edit: Wanted to edit code section to include all bitmap code, not just the save.
Not sure about the specifics, but that is a lot of code within in Page_Load function.
Generally, the way I would solve this type of problem is to have some sort of page arguments that you can check for in order to do the correct things. Either add some get/post parameters to the call that you can check for or check things like the Page.IsPostBack.
I realize this is an old post but I had an similar issue where the page was firing twice on the postback. I found several posts sugesting what is being dicusses here. However, what corrected my issue was setting the page directive property AutoEventWireup=false at the page level.
Here is a good article How to use the AutoEventWireup attribute in an ASP.NET Web Form by using Visual C# .NET that helped me solve this.
Hope this helps!
Risho
I'm sure this question has been asked a million times, however I haven't been able to find an answer that solves my problem.
I am programmatically adding some custom user controls to a PlaceHolder which I have on a simple aspx page. All of the user controls Postback's work correctly except for one which has a Gridview on it.
For some reason any postback that gets fired from within this control, does not call the specified event on the first click, however all future clicks it will work fine. I have no idea why this is the case, but many solutions I have found, suggest adding an ID to the ascx User Control, however this doesn't work in my case.
I've taken a look at the source file for the page that gets generated before and after the first click, javascript used for calling the postback changes, i.e
Before first click: onclick="javascript:__doPostBack('tmpControlID$sgvPrimaryEmploymentHistory','Select$0')"
After first click: onclick="javascript:__doPostBack('OFFHome1$tmpControlID$sgvPrimaryEmploymentHistory','Select$0')"
OFFHome1 is the parent user control which exists on the aspx page. All other controls are added to a placeholder in this control, i.e.
<%# Control Language="vb" AutoEventWireup="false" CodeBehind="OFFHome.ascx.vb" Inherits="UmbracoUserControls.OFFHome" %>
<asp:PlaceHolder ID="phOFFSection" runat="server"></asp:PlaceHolder>
Nothing to complicated. Then in the code behind the controls are loaded into the placeholder using the following:
Private Sub LoadNextOFFStep()
Dim ControlName As String = "TestControl.ascx"
phOFFSection.Controls.Clear()
If ControlName IsNot Nothing AndAlso ControlName <> String.Empty Then
Dim NewControl As Object = LoadControl(ControlName)
With NewControl
.ID = USERCONTROLNAME
Dim StepCompleted As Boolean = .FillControl()
If StepCompleted Then
Exit Sub
End If
Dim AllowSkip As Boolean = .AllowSkip()
btnSkip.Visible = AllowSkip
End With
phOFFSection.Controls.Add(NewControl)
End If
End Sub
Again, nothing overly complicated. The USERCONTROLNAME is just a const with the value "tmpControlID" in it.
The control that is giving me trouble is a little complicated, I was originally using a custom GridView control that we have created, but have removed it and replaced it with the standard asp one to see if the problem still occurs, and it does.
Any button, on control which fires off a postback will fail the first time, and all future click will work correctly. On the first click the Page_Load event will get called, but that is it.
What am I doing wrong??
After far too much time spent on this, I have finally worked it out.
It was to do with the order of events, however just not where I had thought. The FillControl function was getting called before User Control had been added to the PlaceHolder. I changed this so that it gets called after the User Control was added to the PlaceHolder and now it works first time.
Basically the code looks like this now:
Private Sub LoadNextOFFStep()
Dim ControlName As String = "TestControl.ascx"
phOFFSection.Controls.Clear()
If ControlName IsNot Nothing AndAlso ControlName <> String.Empty Then
Dim NewControl As Object = LoadControl(ControlName)
With NewControl
.ID = USERCONTROLNAME
Dim AllowSkip As Boolean = .AllowSkip()
btnSkip.Visible = AllowSkip
End With
phOFFSection.Controls.Add(NewControl)
Dim StepCompleted As Boolean = CType(phOFFSection.Controls(0), Object).FillControl()
If StepCompleted Then
LoadNextOFFStep()
Exit Sub
End If
End If
End Sub
Thanks for everyone's help.
Well... the answer to the first question is simple: It fails the first time because the ID of the control (or rather, in the postback script) is different on subsequent page loads. It works on subsequent clicks because the control ID stays the same.
Now as to WHY that is... much tougher! But probably something to do with the order of operations here.
Try explicitly setting the NamingContainer value for NewControl:
With NewControl
.NamingContainer = OffHomeOne; // whatever
.ID = USERCONTROLNAME