Windows Form App Ignore Event Handler On Page Load
Oct 24, 2009
I have a windows application that has a tab control with 5 different tabs. Each of these tabs has a datagrid view that is populated with data on form load with data from SQL Server. I have an event handler for the datagrids for CellValueChanged that appends an asterisk, "*" to the tab, when a change is made, this is meant to mimic the same behavior in VS or SSMS. The issue that I have just realized is that on page load as the datagrids are populated this event handler is raised thousand of times. I have included an If Then statement to exit the sub if it occurs during page load, but am concerned about the performance implications, if any. Is there a better way to handle such functionality? Possibly a way to ignore the event handler on form load? If not is there a negative impact leaving this functionality in?
I have a form that is built and loaded dynamically when File/open is selected.however I now want to use the same code to open a default file and populate the form using the Form load event to call:
Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click how would I do this? Just incase this doesn't make sense, I want the same code to run during form load as if the user selected file/open but do not know the syntax of how to call OpenToolStripMenuItem_Click() from form load.
i am wanting to add handler for controls i add at Page_load at page load i added several image buttons and applied the image urls using -i used the borderwidth propertiy for padding as was having trouble getting a cssclass to work. [code] what i want these Image button to do is when clicked a larger image in another panel will appear so i will need to assign the clicked buttons image url to the large image controls, image url
Everyting is OK, but when I click on F5, it refresh the page and run the code another time. This means a new record is added to the data base on each F5.This is my code, do you have any advices?
Imports System.Data.OleDb Partial Class Default2 Inherits System.Web.UI.Page
For several days now I've been messing around with Ajax calls using different combinations of javascript, ASP controls, and regular controls. I've gotten a bit of understanding about what's going on, but using ASP controls still hides too much of the machinery, and I want to have a deeper understanding. With that aim, can anyone tell me why the following setup doesn't quite work?I have a file "Testy.aspx" with the following:[code].....
So, I hoped to make my .aspx file do double-duty both as the regular-page request handler as well as the Ajax request handler. However, when I click the button ("baroo") to generate the Ajax request, the result that ends up written back to the "testytext" div is the raw html for the entire page, as if under normal request conditions. Clearly, my attempt to override the page request by making the code-behind implement IHttpHandler and supplying an "Overrides Sub ProcessRequest" method is not working. The server is still treating the Ajax request as a normal request, and in fact my own "ProcessRequest" method is never even called.Is it possible to build a page/handler like this? How can I intercept the incoming request from the client and respond accordingly?This is how Ajax works, right? So it must be possible.Again, I'm deliberately doing this as an excercise to avoid the use of "magic" ASP controls like UpdatePanels,
I am working with database information,and I have to add code in a dateforms , load event handler .That should set the value of the date time picker to match that of the date time picker in the main form?
I'm using FileSystemWatcher in an application.it monitors the files in a folder, then do some processing. I monitor FileCreate, Change, Rename, Delete event.the problem is: when I copy some images to that folder, it fired the create event, but the file is not actually ready, so, when I load the file in the event handler, it failed.how can deal with this correctly?
My current problem, as stated in the title, is that I am trying to create a series of buttons from a custom class within app_code and place them on a master page. The whole reason for this is I do not want to have to copy and paste event handlers on the content pages.
However, upon the click of these buttons I need for a method on the content page to be called and update html within a div of the content page.Is there any way to accomplish updating the div of the content page from an event handler in the custom class? Remember, the method that updates the div exists on the content page.
I am trying to learn Visual Basic and am working through a text book that my son used for a class. Each time I create an event handler by double clicking on the design page, the code that automatically populates is almost identical to the code in the book, except the byval portion is omitted from the code.[code]
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
I am having an Activex Application (dll) which contains a third party control ie a Chart Control, as well as a Windows Application(.EXE). I am using that dll project in my exe application in order to populate the Activex user Control. If i double-click on the Activex Control, how can i pass an event handler from this dll Project to Windows application? If this event gets worked successfully, i have to load a screen from that windows application.
When the user clicks on the Activex Control, ie the Chart Control, is there any way to send a event handler from dll project to Windows Application?
I am using VB.NET for Windows applications. What is the difference between Load event,Activate event and Enter event in the Form and in which order the above event is executed.
I have a Windows form in VS2010 with a rectangular area that I draw in with Graphics.DrawImage for best performance. I want to create a Mouse-move event handler just for that area (to change the cursor when the mouse is inside it), along the lines of handlers for the other controls on the form. But since the rectangle isn't a PictureBox or Panel or other control, I don't see an obvious way to handle it. A mouse-move event handler for the entire form could affect the performance of the app.
I have a simple, but important question: How can I raise events of my form1 on another module/form?My form tempalte is crowded with events (50 of them contextmenustrip events)How can I place those events on another form/module to clean it up a little?
I'm trying to execute different code depending on the button clicked (button 4 or 5) on Form1, but when I click on button5 to activitae the code on the Form2's Load event everything is Ok, but when I click the back button to return to Form 1 and click on the Button4 to activate the code on the Form2's Load event again, it doesn't active the Form's Load event, is there a way to form the form load event every time I access it from Form1? [code]
How to retrieve the particular row of detailsview into textbox on page load event if details view defaultmode is readonly..i want to retrieve the email id from detailsview email row in textbox1 on page load event ?
When I double click on a form control while in the design view in a Web Application project within Visual Studio 2010, say a 'button' or a 'submit' for example, it inserts a javascript function into my .aspx file. When I do this at work it automatically creates an event handler for the control in the code-behind.How do I change this to that setting?I don't want to type those event handler subroutines every time!
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?
ll app build in VB 2005 that has a DLL. The app runs fine on 32bit systems but fails on 64-bit ones (Failed to load the assembly: BadImageFormat from the DLL). As I could not fix the problem I wish to somehow ignore this error so the rest of the app can run normally. I wish to retain the funcionality on 32-bit systems thus not removing the DLL from the project.
The title pretty much precisely asks the question, but I shall repeat;
When I double click on a form control while in the design view in a Web Application project within Visual Studio 2010, say a 'button' or a 'submit' for example, it inserts a javascript function into my .aspx file. When I do this at work it automatically creates an event handler for the control in the code-behind.How do I change this to that setting? I have used '/resetsettings' already, and other answers to similar questions do not solve my problem. I have reinstalled, gone through every menu I can find (though I may have missed something)I don't want to type those event handler subroutines every time!
I have two forms. Form A and Form B. Form A has a datagrid that is populated from a SQL Database Table query. When a button is pressed Form B is launched that allows you to add a record to the database table. I need for the datagrid to be refreshed and show the newly added record when I close form B and go back to the parent.
I fear that there is something obviously wrong with my code, but I have come across a situation where the Form.Load event is not firing when I create and show my form. The form is not subclassed (as I've seen some problems with that in some searches), and I am not getting any errors thrown when I step through the code in the debugger.
I have a break point set on the IDE-created form load function (which does have the Handles MyBase.Load signature suffix) but the breakpoint is never reached and the form does display and work.The form is passed three arguments in the constructor but the IntializeComponent() function is called before anything else is done.
I want one form frmFrontEnd to be the base of my application, so when i press F5 it is the first to 'open/be seen' and then from here using previous i want other forms to open. How can i set frmFrontEnd in the form load event to be the parent form? If you're not living on the edge, you're taking up too much room
