I was just starting to learn how to use classes today and I think I might have a vague handle on them.Anyways, I was using a class to generate troops (as objects, since I needed various statistics tied to each individual one) in an army for sort of a basic medieval-type game I was creating and adding them to a combo box.It all works perfect and the index holds my object and I can call data from it, etc., my only issue is with the aesthetics of my result.All of the troops I add to the combo box as objects appear in the dropdown list as "WarProject.Soldier", the name of the object. This is obviously not something an end-user would understand or want to see. I have no idea how to change what an object appears as in the combo box.
I have two combo boxes. box1 and box2 both on same form. Depending on what is selected in box1 will determin the items in box2. I would like box2 to change in real time (not pressing a button!)
Whats the best way to do this? use a timer on the form with lots of if else (or case) statments?
I am getting an error when i try to populate some combo boxes with a value, the combo box has values in and the right amount the code is getting the right number.
the error msg is "Object reference not set to an instance of an object."
LANGUAGE: Visual Basic .NET VERSION: 3.5 IDE: Visual Studio 2008 OPTION STRICT: on OPTION EXPLICIT: ON
I need to populated a ComboBox and a CheckedListBox with a list of the Windows Accounts on the host computer. I also need to the user to be able to apply settings to the users individually. Thirdly, I need to find a way to add a startup registry key in the CURRENT_USER for a different user than the "Current User" (For example: User1 is an Administrator. User2 is a Limited Account [can't modify registry]. User1 needs to add Registry key to User2's "CURRENT_USER". This is a parental control application so the Admin accounts need to be able to access the registry from all users without affecting all users at once. I do not have any code to paste because I still have not the foggiest idea of where to start. I think it probably has something to do with an array (I have no experience with arrays whatsoever) but I am stumped from there. I'm a new, self-taught programmer so I speak idiot at times,
Summary of Questions 1) How do I retrieve a list of Windows Users? 2) How do I populate the objects above with such a list? 3) How do I interact with the items on that list (specific user accounts)? 4) How do I modify another user's CURRENT_USER Registry key?
I'm trying to add some features to a program my company has developed over the course of several years and I'm having trouble setting the combo box to the proper index. I have successfully populated cmbIGDefaultSpacer with the color options that are available but can't manage to have it set the current color as the index. (I can, however, display the current color in a text box, so I know that the necessary values are being passed to the form.) The error I get is 'Object reference is not set to an instance of an object.' in regards to this line:
In a windows forms project, I have several combo boxes. The first combo box contains a list of objects. Those objects then have several lists which are used as the datasource's for the successive combo boxes, depending on which item is chosen in the first.
Well I'm using VB 2010 and I need my 'Sub Main' coding to start before my forms do. But I can't find the Start Up Object combo list anywhere! I can find a Start Up Form combo list, but (as the name suggests) it only lists my various forms. I need my 'Sub Main' coding to start first!
So I wanted everyone's opinion on this and what you think of this. Using the WithEvents modifier makes life very easy in VB.Net (srsly, I love it), and I was exploring some of its limitations and noticed you can do something along the lines of this:
I'm trying to change the reference of a variable passed from one form to another in the constructor of the recieveing form but after I've changed it the original reference still remains in the source form. Why is this and can I force it to accept the new reference?
I am developing an windows application in VB 2008, My requirment is such that I have to change the applications Splash and Startup object on the basis of "Custom Constants" (Compilation Constants).As far as I have .Net idea it should be done in Application.Startup Event (guide me if i am wrong)Now, in Application.Startup_Event when I write the code
Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.StartupEventArgs) Handles Me.Startup My.Application.SplashScreen = SplashScreen2
[code]....
The application dont work as desired, instead it starts with Form2 (which is OK), while in case of Splash it doesnt changes the splash form.
i have worked on a culture switch control and i need to modify the ViewContext.RouteData("culture") to check if the view exists anyway when i do the following
Dim routeData As RouteData = ViewContext.RouteData routeData.Values.Remove("culture") routeData.Values.Add("culture", cultureValue)
then the original ViewContext.RouteData is changed when i change the routeData.I have tested to do the following to but no success
Dim tempViewContext As New ViewContext(ViewContext.Controller.ControllerContext, ViewContext.View, ViewContext.ViewData, ViewContext.TempData, ViewContext.Writer) Dim routeData As RouteData = tempViewContext.RouteData routeData.Values.Remove("culture") routeData.Values.Add("culture", cultureValue)
how to copy the ViewContext to a temporary object and changing the values without changing the original ViewContext values?
Edit: The only way i know work is to change the routeData then check if it exists and after it change the routeData back to the original culture... was hopping there were a another way but it works for know.
evrytime i add new controls to a form in vb.net the designer regenerates code and asks me to make corrections, so i have to keep on changing the object declarations to global using the 'global' keyword evertime it regenarates code,especialy dataset objects.how can i prevent this?
The issue is when I try to add a new item to the ArrayList with the following code, it gives me an error:
vb Private Sub btnLabelAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLabelAdd.Click Dim result As String = InputBox("New Filter Label:", "Label List")
[CODE]................
Object reference not set to an instance of an object.
I'm not really sure what I'm supposed to be doing with this. It's a new setting I just added and it's empty, so I'm not sure if that has anything to do with it or not. Anyone know what's going on and what needs to be done to get it to accept a value and not want to be "initialized"?
I have recently gotten my hands on a free, open-source IMAP connection API.So far, I have been successful in creating a connection to one of my accounts.Where I'm getting stuck is retrieving folders and/or emails from those folders.Does there happen to be anyone here that is familiar with this API, or even Gmail (particularly the folder structure for IMAP)?
If not, here is a link to the DLL that is listed on sourceforge and the company's website that created it (if you feel like testing):
Koolwired Sourceforge - Koolwired API
I have created a test account so feel free to use the code below without worrying about username/password issues; I'll just delete it when I'm done with it.Here is the code I have made so far for making a connection:
Dim gSession As New Koolwired.Imap.ImapConnect("imap.gmail.com", 993, True) Dim gAuthenticate As New Koolwired.Imap.ImapAuthenticate(gSession, "imap_test@serysoft.com", "imap_test") Try
[code]....
When I run that code, I get an error that states:System.NullReferenceException: Object reference not sent to an instance of an object. (The bold line in the above code).
Now, I'm not sure exactly what that means. Does that mean it tried to access the server and "INBOX" doesn't exist so it gets returned a NULL value? Or is it possibly the coding itself?Maybe the Gmail folder system is weird due to the fact they use labels (even though from what I have read online, the labels act as the folders in the IMAP system).
I create one function to run any select query. and return the OdbcDataReader type.But some time if there is no data it through error : Object reference not set to an instance of an object I need to know how i can control if there is no data.
Public Function Select_From_AnyTable(ByVal sqls As String, ByVal ConStr As String) Dim conn As OdbcConnection conn = New OdbcConnection(ConStr) Dim cmd As OdbcCommand = conn.CreateCommand() conn.Open() cmd.CommandText = sqls Dim reader As OdbcDataReader = cmd.ExecuteReader While reader.Read() Return reader End While conn.Close() End Function Dim ei As OdbcDataReader = Select_From_AnyTable("SELECT loginname from usertable limit 1", conStr) msgbox(ei.item("loginname "))
If there is data it work well but if no record found it through the error.
Like every other program that you make when you code a button to open the next form it should open right. Well not in my case. I don't understand the problem that Visual Basics is not seeing my next form that I'm trying to open. When its in the Solution Explorer plain as day. Error below.An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object.show is not set to a object. All its doing is opening the next form. Ive use this code over an over. Now its giving me this C.O.S. error.
Basically all I am trying to do is to insert data entered in a text box(description) on the application form into database(sql2008) in vb.net. The vb code I wrote is below:
vb.net Protected Sub Save_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Save.Click Dim note As String = Description.Text
[code]....
However when I click on save button, I get following message:
System.NullReferenceException: Object reference not set to an instance of an object.
What in this code might be causing this??This part of the code is Hilighted as causing the error.
My.Settings.Item(Holiday_" & i) = DirectCast(Me.Controls("ComboBox" & i.ToString), ComboBox).SelectedItem Public Sub btn_Update_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
i wanted to link options selected from Comb box A (general) to specific options in combo box B (specific). I want to pick a word in Combo box A that has specific words/phrases in Combo Box B show. But not all the words to show in the combo box B if they aren't associated with the Word picked in Combo Box A. Ex.When "Soda" is picked in A, only "Coke, Sprite, Fanta" should be visible in combo box b, not everything else.This is the code i used to make the boxes, but i don't know how to link them.
Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ' fills the combo boxes with values Me.xGeneralComboBox.Items.Add("Soda") Me.xGeneralComboBox.Items.Add("Juice")
How to use a databound combo box to display one field in the drop down, and another as the combo box text on roll up? Using VS 2005... For example, I have a datatable that has 2 fields. One called "ShortDesc" and one called "LongDesc". I want to be able to see the "LongDesc" column values in the drop down on the combo box. When I make a selection, I want the text in the combo box to read the corresponding "ShortDesc" value.
Combo box 2 is filled based on a selection made in combo box 1 and a listview is populated based on the selection made in combo box 2.When the LostFocus event completes in combo box 1, it hits the LostFocus event in Combo Box 2 but it shouldn't. How do I prevent this from happening or if I can't prevent it, how do I work around it? The following is the code used.
Private Sub cboCategory_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles cboCategory.LostFocus
I've got some code like the following. I want it so that when I chose an item in 'select 1' it changes the in the second combo box but I'm not sure of the best way to go about it. Does it have to be AJax or can it be done with just Javascript?
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head>
I am trying to clear a dataset in case it has some data already in so that I can add data to it to search a database, but when I run the program and get to the point that it tries to clear the dataset I get this error message "Object reference not set to an instance of an object", here is my
dtasetUser.Tables("tblUsers").Clear()Also I get an error "The 'Microsoft.ACE.OleDB.12.0' provider is not registered on the local machine" when trying to fill the same dataset, on searching I have found it is because I am trying to open a 2010 Access document in VB08, but I have no idea how to remedy this and any instructions I have seen make no sense to me, so I would like help with that too please.
I am able to populate an object and output everything. How do I remove say the name2 object?
la.Remove(Logins("name2")) doesn't seem to work. Private Sub btnListArray_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnListArray.Click
I'm trying to make a search textbox bring up certain records in a DataGrid. This is my code for that function:
Public Function Find(ByVal StrSearchString As String) As Boolean DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect Dim intcount As Integer = 0 For Each Row As DataGridViewRow In DataGridView1.Rows
[code]....
The problem comes on this line:
If DataGridView1.Rows(intcount).Cells(0).Value.ToString = StrSearchString Then
I can't figure out what the unhandled exception is. Any ideas? I'm sure it's something very simple I'm overlooking.
I'm searching for a way to change the font size of selected text in a RichTextBox (rtf) having different font families (e.g. Arial and MS SansSerif) and font styles (underline, bold...) using the FontDialog, but without changing the families and styles. The following code resets all the font attributes, which is not what I want:
