Asp.net - Use A Page_load Local Variable In Event Handler Of A Button?
Apr 27, 2009
Im making a site in Visual Studio using vb and I have a variable in page_load but need its value in the event handler of a button for passing on session.
I have a form in VB.NET that is used as a dialog in a mainform. Its instances are always locally defined, there's no field for it. When the user clicks the OK button in the dialog, it will fire an event with exactly one argument, an instance of one of my classes. Since it is always a local variable, how can I add an event handler for that event?
Code for the event, a field in MyDialog: public Event ObjectCreated(ByRef newMyObject as MyObject) Code for the main form to call dialog : (never mind the syntax) Dim dialog As New MyDialog() dialog.ShowDialog(Me) AddHandler ObjectCreated, (what do I put here?) //Or how do I add a handler?
I have two radio button on my asp.net page, with AutoPostBack = True When I click on either of those, they each set a flag SaveData=False However, when I click on them, the page_load event occurs first, so the page_load event saves the data, then the radiobutton_OnCheckedChanged event is triggered. How can I trigger the OnCheckedChanged before the page_load event?
On one side, in Vb.Net when you add an event handler to an object the created method is named: <NameOfTheObject>_<NameOfTheMethod>.As I like to have consistent syntax I always follow this rule when creating event handlers by hand.On the other side when I create private variables I prefix them with m_ as this is a common thing used by the community, in C# people use to put _ at the beginning of a variable but this is no CLS compliant.
The event handlers in my parent class are never called though the events are raised in the child class.
The Code:
Public Class childForm Public Event checkboxchangedEvent(ByVal checkbox1 As Boolean, ByVal checkbox2 As Boolean) Private Sub checkboxchanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged, CheckBox2.CheckedChanged
When you click on a button control on a web form visual studio automatically put in this code for you in the code behind. Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnFlightInfo.Click end Sub
Say for example, I wanted to call this method from another method. How would I do that? I know that the sender is the actual button object, but what is e? Here is what I have so far inside another sub. Just trying to get a better understanding of how this method works. btnSave_Click(btnSave, ??what would you put there??)
Reading about VB .NET I found out that now it is possible to handle more than one control with the same event handler. What I want is to specify what my Radio buttons will have to do, using a single sub instead of using a sub for each of them. However I am still far from achieving that. I am using something like that:
Private Sub ForAllRadioButtons_CheckedChanged_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadioButton1.CheckedChanged, RadioButton2.CheckedChanged, RadioButton3.CheckedChanged If sender.name = RadioButton1 Then Code 1 ... ElseIf sender.name = RadioButton2 Then Code 2 ... ElseIf sender.name = RadioButton3 Then Code 3 ... End If End Sub
However, I get an error message which says : Operator '=' is not defined for types 'Object' and 'System.Windows.Forms.RadioButton'. I bet 100 $ that it's something that I don't do it right . Unfortunately I can't get that money. Would it be the same if use the Click event instead of the CheckedChanged ?
During the process of my program I am creating several different buttons depending on what file the user selects. I have been able to create these buttons and I would like to set up the event handler so when the user selects one of these buttons it pops up a message box that shows the user the name of the button they just clicked on. The message box isn't the goal of what I would like to do with it but If I could get that to work I would be able to alter the code to get it to work the way I want it to.
Below is my code that I currently have. I don't have the event handler doing anything at this time as I can't seem to get it to work I am still playing around with it.
ublic Sub resizebuttons() Dim X As Integer = 175 For Each item As String In CSVInput.selected
I'm creating an ASP.NET Custom Control for my web application which is basically an ASP.NET Button control contained inside multiple <div> elements (for styling purposes).How can I create a Click event handler for my custom control so that my control acts as an ASP.NET Button?
Ie.
<cc:Button id="myButton" runat="server" Text="Submit" /> Sub myButton_Click(sender as object, e as EventArgs) Handles myButton.Click End Sub
i just start programming in asp.net i struggling to add event handler dynamically. here is the scenario when the aspx page is load a link button is add with an event handlerpage load add link button and event handler with link button
Dim products As New LinkButton products.Text = "Products" testPanel.Controls.Add(products)
assistance.My Objective: create project that allows the end user to add data to a textbox then select desired rows via checkbox column in a datagridview. Once the end user has selected all desired rows for update then on button click commit data from textbox to cells belonging to the alert_notes column.
I have a problem with running code in the right order. What I am trying to do is updating a session state variable when I press a button. When I run my code it always runs the event handler for the button after my page_load function.The reason why I need to run it after page_load is that, thatI add a line to the textList. Which the loadGui() should add to a table. The table has a remove button for all lines so the loadGui() function can not be added later becuase then the event handler of the remove buttons wont work.
User press the add button which add a row in the TempResponse Session(TempResponse) gets updated loadGui() runs and includes the newly added row Sub Page_Load()
I am populating the DropDownList ddlItems in the Page_Load event. I am then changing the current selection of the DropDownList in the Page_Load event but the dropdownlistbox.SelectedItems aren't firing up. Can anyone please help me? The dropdownlist keeps on repopulating and I cannot stick with one value that I have selected.Here's a screenshot of the problem.I want to have the value LK00260 selected when I PostBack.Instead of having to see "Add New Item" everytime I postback OVER AN OVER AGAIN.
[code]...
I don't want 'Add New Item' to show up everytime I repopulate the box. Instead, I want a value that I have selected such as 'LK00260'. Can anybody please help? I have AutoPostBack set to true already.
I'm fiddling with sessions in asp.net in a http module.The problem:
session("whatever") = "something"
is set on page_load I need an event in the http-module which is executed after page_load, and in which I have access to the session in System.Web.HttpContext.Current.Session I was looking at this HTTPModule Event Execution Order? but I can only get the session in PostAcquireRequestState, which obviously comes before page_load...
sub Page_Load //Get data form databse and show it end sub sud deletsome(Source As Object, e As EventArgs) //delete one record when user click on submit button end sub
When I click the button, the page reload, all the data have no change, I must re-enter the page again, the record I have delete disappear. Can you show me why? The full code here:
remove an event handler from within the event handler?
I have a class that gets data from a hand scanner. When the scan is complete and the data is validated, the class fires a custom "ScanComplete" event and returns the data in a custom EventArgs.
In the calling program, I'm creating an instance of the scanning class and adding a handler for the "ScanComplete" event. In the event handler I get the data that was scanned and then remove the handler.
It seems to be working but it feels wrong to remove the handler while I'm running inside the handler. Will this cause a problem?
I'm wondering whether it is possible to declare a global variable in a click event. I need to declare an array of a specific size. The specific size is generated using a series of IF statements. I only need to know how to declare it.
I'm trying to complete this airline reservation application, but having a problem in this part of the question:Creat an event handler for the FlightBindingSource's PositionChanged event: select FlightBindingSource in the class Name combobox then select position changed in method name combobox to creat the FlightBindingSource's PositionChanged event handler. Write a code to access the currently displayed flight object and pass its flightNumber to method DisplayPassengers as a decimal.This Is my code so far:
HTML
Public Class AirlineReservationForm Private database As New ReservationsDataClassesDataContext() Private Sub FillAll()[code].....
When I utilize AddHandler in VB to add my own method to the Click event :
AddHandler Button.Click, AddressOf myButton_Click
I see that my code executes last - after other event handlers for the Button_Click event. Is there a way to insert my event handler in front of other events so that it executes first?
I have a form that I am adding a set of buttons to. I am adding an event to those buttons. I need this event to function slightly to determine what button was pressed.
I need the button to simply set a string variable equal to the clicked buttons text so I can determine what button was pressed.
How can this be accomplished?
''Adding the buttons'' For Each dr In dtMenus Dim strMenuName As String strMenuName = dr.Item("strMenuName").ToString
I am planning to use a shared variable to implement a logging facility. Have a look at the code below:
Imports System.IO Public Class TestClass Public Shared objError As New StreamWriter("C:Test.txt") End Class
[Code]....
I think I have found my answer here: [URL] "A static variable continues to exist and retains its most recent value. The next time your code calls the procedure, the variable is not reinitialized, and it still holds the latest value that you assigned to it. A static variable continues to exist for the lifetime of the class or module that it is defined in."
I am not convinced that this is the best way to create a logging facility.
When I've used the remove handler method in my code, I get this warning:The 'AddressOf' expression has no effect in this context because the method argument to 'AddressOf' requires a relaxed conversion to the delegate type of the event. Assign the 'AddressOf' expression to a variable, and use the variable to add or remove the method as the handler.Why do I have to assign the "AddressOf" expression to a variable?
Is it possible to determine using VB.NET whether a certain event has any handlers attached to it? I don't own the event, in this particular case I want to know which of the items in a Windows.Forms.MenuStrip have their ToolstripMenuItem.Click event handled.