Private _PurchaseDelivery as PurchaseDelivery Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As PurchaseDeliveryItem)
[Code]....
Which is inside a class which overrides a custom list base. The code is occassionaly throwing an unhandled exception, System.NullReferenceException, on this line when used in production:
If _PurchaseDelivery IsNot Nothing AndAlso _PurchaseDelivery.DefaultSKUBinID.HasValue Then
DeafultSKUBinID is declared as an Integer? (Nullable Int) in the PurchaseDelivery class. I cannot see what might be causing this error, why would this be returning an error?
When I put a break point to the last if clause in the sub ("If (backOrder < 0) Then", see below) it runs until the break point, if I put the break point further below, I get the following error:
Cannot insert the value NULL into column 'OrderID', table 'WHM.dbo.OrderDetails'; column does not allow nulls. INSERT fails. The statement has been terminated.
I've discovered first hand that it only happens when prodqty is bigger then qtyOnStock, thus executing the if clause.
The code:
Private Sub NCOSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NCOSubmit.Click Dim sqlText As String = ""
I am testing a program, and I am getting a null reference error at this line. oParent.Invoke(oParent.cUpdatingSolidWorks, iSolidWorksItem). I have stepped through the program, and all the items are created. A watch window with the three objects all have data in them. I am wondering what would cause this error if the objects exist. [Code]
I am still a newbie with VB. If I return a number the if statement works fine, with opening the new form and updating it as needed. Id the if statement returns a Null from the database it crashes.
While recently working on a program, I've run into two problems.Firstly, let me state my purpose of this program.The users enter a 'script' into the VB program, the program then saves the scripts as a '.java' file, then attempts to compile it using java
Basically, when you set an Integer to "Nothing" it seems to equal the same value as if you were to set it to 0. So, in a function that returns an Integer how can I return something that will show that the function failed? In most cases I would use -1 or something but in this case I need to allow for negative values too.
Here's some more detailed information: I'm using the GetValue method of the Microsoft.Win32.RegistryKey class to read a numeric value from the registry. The GetValue method has an optional argument that you can pass in that specifies what should be returned if the value did not exist, normally I would use Nothing but in this case because I am storing the returned value in an Integer then it is just the same as if the GetValue method returned 0 (which is a valid value in this case).
Example:
vb.net Dim Reg As Microsoft.Win32.RegistryKey = My.Computer.Registry.LocalMachine Dim SubKey As Microsoft.Win32.RegistryKey = Reg.OpenSubKey("SYSTEMCurrentControlSetControlTimeZoneInformation", False)
I am currently working on an SSIS package that we are migrating from SSIS 2005 to SSIS 2008. The issue is that the developers of the current version used the fact that in SSIS 2005 the accessor of a NULL column returns 0, whereas SSIS 2008 throws an exception. Also, they extensively use expressions such as this one: IIf(Row.X_IsNull, System.DBNull.Value, Row.X) The problem is that in SSIS 2008, regardless of whether the condition is set to true, the program still tries to read Row.X and throws an exception. The package is big and it would take a very long time to convert all of these IIfs to manual Ifs with temporary variables.
I have one list that pushes to another list. Think of a shopping cart situation. If you double-click on the white area after the list of items in the first window, I get a null exception error when I push the info to the second window. How can I avoid that error??
Existing Code is below... Private Sub lstBooksAudio_doubleclick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstBooksAudio.DoubleClick If lstBooksAudio.SelectedItem = "" Then MsgBox("Please Click on an item.") [Code] .....
I have a ListView populated with colors one can choose to customize the UI a bit. I want the user to be able to click an item in the ListView and have it's BackColor become the BackColor of a picturebox (the "preview"). This is my
VB.NET Private Sub listColors_ItemSelectionChanged(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ListViewItemSelectionChangedEventArgs) Handles listColors.ItemSelectionChanged clrPreview.BackColor = listColors.FocusedItem.BackColor End Sub
If I try to select a different item with one already selected, I get "System.NullReferenceException was unhandled." How can I fix this?
I have a DataGridView1 populated by sql searches. On the rare occasion that nothing is returned, my app cannot make use of data so I'm trying to check for null values. My code below is not correct because IsDBNull is not a member of the of the DataGridView1.
If DataGridView1.SelectedRows(0).IsDBNull Then MsgBox("Nothing to display") Exit Sub End If
I'm hoping someone can assist. I'm still learning VB so excuse my lack of knowledge. The below code is a mashup of a code snippet I found that effectively reads from an SQLite database. The initial code snippet consisted of a textbox for input, a textbox for output, and also consisted of a datagrid to store the contents and a button to activate the lookup.
I am connected to a MYSQL database and the following Insertcommand works fine:
InsertCommand="INSERT INTO suppliers (Supplier) VALUES (?Supplier)"
Now when I want the option of updating all the columns it keeps saying "Column 'Contact_2' cannot be null" or contact_1, so all the fields need something and not all suppliers of course have two numbers. What am I doing wrong? here is the
InsertCommand="INSERT INTO suppliers (Supplier, Contact_1, Contact_2) VALUES (?Supplier, ?Contact_1, ?Contact_2)"
why I am getting a NULL reference error. Form: Public Sub CreateSession() ' This will be the execution function after the date, provider, session type, session number ' and consumers have been entered. Each Consumer will have it's own tabpage and seperate record.
I have a couple of textboxes whose databinding's text is set and also readonly is true and visible is false. but when I try to read their values they are all null unless I turn their visibilty to true. The same method is also needed to add a new row to the table (when using bindingsource1.addnew()).
What I do is I have a variable on form1 and its an integer which has a value on load of 0 and named count.When I click the 'doSomething' button it is increased by 1 and when I use the function 'msgBox' I get to see 1.After that I start a thread which is going to look up count but when I check the value there is 0.
I have a web application on a Windows 2008 server. The web application opens another application interactively.The issue: If I am logged into the server, the web application runs without any problem. If I log-off, and try to use the web application, I get an error "Buffer cannot be null."If I log myself back into the server,go to another computer and try the web app, it will work fine.What security setting is causing this?
I have the following If Trim(txtConfirmationDate.Text) <> "" Then sqlinsert2.Parameters.AddWithValue("@CONFIRMDATE", CDate(txtConfirmationDate.Text)) Else sqlinsert2.Parameters.AddWithValue("@CONFIRMDATE", VB.vbNull) End If Unfortunately, it writes "01/01/1900" to the database. How do I get it to just leave the field as NULL?
When I debug my code I notice that some of th code below is skipped when an integer is not filled in in the DB.Example:When the value of the piece of code in bold (Aanspreektitel_ID) is null in the db the code skippes the rest of the code blok and thus not filling the values on my form.
I have a datetimepicker and combobox on my form. If a user does not change the date on dtpicker or does not change text on combo box, these controls return null value, and the save operation fails. The controls are bound to data in a database.
I just tried to convert some of my Projects from VB2008 to VB2010 RC, but got compiling Errors while compiling the resX Files. Seems like the reason are ImageLists/Icons, since if I remove them the files compile fine. I already tried to edit the Forms witch are showing the Errors with the Designer. The Designer changed the Content of the resX file lightly, but the error was still present Here the Error(German Version): 'FormsfrmUserTmpBUTable.resx : error RG0000: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.' I recall a similar error in the Beta, but since I can't find it anymore, I guessed it was fixed.
How can I get this to happen? I googled around and it seems setting the CUSTOM FORMAT to " " when the field is null will work but not for a BOUND datetimepicker.