Getting Null Reference While Reading From A Cell
Nov 21, 2011I'm having this exception while trying to get the value of a cell from a table.[code]...
View 2 RepliesI'm having this exception while trying to get the value of a cell from a table.[code]...
View 2 RepliesIf a column contains null dbnull value in sql server database then how can i replace it with "N/A" string when i view the database table in datagridview
View 2 RepliesI have a fairly simple piece of code:
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?
I have several date fields in a datagridview, in sql these are saved as navchar fields. If the user needs to clear the date they can do so by highlighting the field and pressing the delete key. This clears the date no problem, unfortunately it sets the field to Nothing or "" (a blank). I need it to set it back to NULL for reporting purposes.
Here is the relevant part of the code:
Private Sub dgvWeldingLog_CellEndEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgvWeldingLog.CellEndEdit
Try
If dgvWeldingLog.Columns(e.ColumnIndex).Name = "dgvtxtDateWelded" Or _
dgvWeldingLog.Columns(e.ColumnIndex).Name = "dgvtxtFitCheck" Or _
[Code] .....
If there is an error in the data entry then the form cannot be saved. When I trap DBNull.Value is says it is equals to "Nothing" and not "NULL".
This is related to my previous question but it is a different problem.I have two classes: Server and Database.
[Code]...
The problem is in the LoadTables in the Server class. When it hits Databases.Add(db) it gives me a NullReference error (Object reference not set). I don't understand how it is getting that, all the objects are set.
I want to display a message if the value of cell of my datagridview is Null.
View 1 RepliesWhat im trying to do is check a row for null values in my datagridview before saving the data back to my access database, in particular the first columns cell of the new row being added. This is the code I have so far'
Private Sub LatheprogramsBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LatheprogramsBindingNavigatorSaveItem.Click
Dim test As String = Me.LatheprogramsDataGridView.Columns(1).ToString()
[code]....
I have a program in which I am doing a sql select on two tables with an outer join. In one option of my search I need to show all items in both tables so some items in the row will come back with a null value. I am familiar with using the DefaultCellStyle.NullValue = which works great when replacing Null values with the same value.
I am in need of replacing the null value in column 0 with the value in column 10. I think I am close but have not had any luck researching this on my own. Here is what I have.
dgvInventory.Columns(0).DefaultCellStyle.NullValue = CStr(dgvInventory.Item(10, ???).Value) if I replace the ??? with any value I get that rows data but all null values become the same, what can I do to tell it to replace the current rows column 0 with the current rows column 10 if column 0 is null.
I have some code which gets child items for a menu via the GetChildren function which takes a list of menuData: Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
If menuData.Children IsNot Nothing Then
menuData.Children.AddRange(GetChildren(menuData))
End If
Next
If I check if menudata.children isnot nothing, it always is nothing because the GetChildren function is yet to run (providing the child items, which do exist). If I remove this check and just have this code:
Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
menuData.Children.AddRange(GetChildren(menuData))
Next
Then I am presented with a Object reference not set to an instance of an object error on menuData.Children.AddRange(GetChildren(menuData))
I have the following code that checks if the value in a cell contains a nummeric value.
Private Sub dgvOrderRegel_CellValidating(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles dgvOrderRegel.CellValidating
Select Case e.ColumnIndex
Case 4 'Aantal
If Not IsNumeric(e.FormattedValue) Then
[Code]...
I have been trying to use sockets in VB.NET and once I cannot understand how to avoid a null reference. [code] I have tried introducing sock as 'New Socket', but this gives me 'Overload resolution failed because no accessible New can accept this number of arguments'.I also cannot simply add '= Nothing' onto the end of my declaration since this still gives a null reference.
View 6 RepliesI'm practicing on this one, and I know it would be better to just use a string variable instead of a class. I have another working program using a string variable, but on this one I wanted to make it use an array of class objects.
I keep getting null reference exceptions at the line where the object is assigned the textbox text.[code...]
How do I check for a null object in a subroutine handle?
Private Sub Form1_KeyDown( _
ByVal sender As Object, _
ByVal e As System.Windows.Forms.KeyEventArgs) _
[code]......
I have a null reference warning. Dummy code as follows:
Dim poo As IEnumPooTypes
Toilet.GetPooInBowl(poo)
The variable 'Poo' says it may result in an object reference not set error but I cannot use the 'New' keyword with an instance. How do I make the warning go away?
visual basic application prompting me a message "Object reference not set to an instance of an object". i have 2 project in one solution. One is developed in c# and other is in vb. i am calling a method of c# project in vb project. the vb code is:[code]when i debug vb project individually it works properly and when i call vb application from c# application, it prompting error. is i missed out any .net framework reference? [code]
View 1 RepliesIm trying to write code that will insert 'records' into an xml file, but everytime i click the button to make the changes to the XML file, it throws a null reference exception, ive gone through this code must be 100 times and cannot find what needs to be declared as 'new' as i know nodes can't be 'new' and the doc is 'new'
Imports System.Xml
Public Class frmuseradmin
[code]......
Using VB.Net, I am reading an Excel spreadsheet does anyone know what might cause a cell to be read as VBNull when it contains data?the cell clearly contains data. and what is extra weird is all the same cells in the rows before and after the bad one have the little green triangle in the upper left corner, indicating an error - but they all read fine the cell that reads as NULL is the cell in row 4 above
View 1 RepliesI get a 'Conversion from type DBNull to String is not valid' error when I proceed to insert the row with a null cell value from my program to MS Sql Server even if the column is already set to accept null values in the database. How do I solve this? FYI I'm using an unbound datagrid, and I get all the screen values during runtime.
Property SerialNo()
Get
Return strSerialNo [code]...
My site has been running fine for sometime now until recently I see in the event viewer a null reference exception in the DNN core:
DotNetNuke.Common.Globals.GetStatus() in
F:BuildsMaintenanceWorkingDirectoryLibraryCommonGlobals.vb:line
1125 at DotNetNuke.Common.Initialize.InitializeApp(HttpApplication
app) in
[code]....
the line 1125 is:
_Status = UpgradeStatus.None
Which is a property of the Globals class and an Enum Also when this happens it doesnt just do it once then sort its self it does it roughly every minute for an hour or so.I made sure all dataprovider.instances are either in a using or a try catch finally or self closing(if the reader is not used)?
I have the following code, which is meant to loop through a list of CheckBoxes and if checked if gets the text contained in the linked textbox through the tag of the Checkbox, i have used it before and it worked fine but this time i am getting the following error:
Null Reference Exception was unhandled
Dim DisCheckBox As CheckBox() = {chk0_6, chk6_12, chk12_18, chk18_24, chk2_3, chk3_4, chk4_5, chkXSB, chkSB, chkMB, chkLB, chkXLB, chkS, chkM, chkL, chkXL, chkXXL, chkXXXL, chkXXXXL, chkW8, chkW10, chkW12, chkW14, chkW16, chkW18, chkW20}
For Each Chk In DisCheckBox
[code]....
I know I'm being an idiot here and I just can't work it out. But i'm trying to take some data back from a vb.net database. It's falling over with a Object reference not set to an instance of an object error. And before the code runs it's saying the variable is being used before it's set, but I can't see how. Code:
Private taNotifications As dsDataTableAdapters.NotificationsTableAdapter = New dsDataTableAdapters.NotificationsTableAdapter
Dim notification As dsData.NotificationsDataTable = taNotifications.GetDataByClientID(userrow.UserID)
If notification.Rows.Count > 0 Then
Dim notificationrow As dsData.NotificationsRow
Dim forwardURL As String = notificationrow.ForwardLocation
End If
It falls over on the Dim forwardURL As String = notificationrow.ForwardLocation
P/Invoke on x64 null reference exceptions, I get null reference exceptions when I try to compile for x64 in .NET code that makes use of platform invocation services to call unmanaged code in dlls. Am I missing something obvious here?
[Code]
I keep getting a null reference exception w/this program, and its on the line that declares the array. I've looked it over and over and I just don't see why... Can you let me know if you see anything obvious? I'm also getting an "index out of range" exception, but it looks right to me...I declared everything with an 11 for 12 months, 0 to 11 for the intcount.
[Code]...
If Not obj is Nothing and obj.IsActive Then ' null reference exception??constructions like this in C# works, because obj.IsActive is not checked if the first condition is false...
View 2 Repliesi have this sql transaction i am using to make sales.But when ever i run the code it give me this null reference exception.I do not really know what is wrong.
[Code]...
Now, when I try to debug my program, it immediately throws the exception below, this is before entering the program itself if I understand correctly. Any advice on how to resolve this? Between now and the last time I tried running debug, I had tried making a section of the program MDI, but gave up on that and delete that code. Also none of that part of the program is even in a position to be ran (the initial interface and onward do not execute that code)
[Code]...
I'm currently taking a VB class and i'm having trouble running my program properly.[code]
View 3 Repliesstarted learning vb.net..encountered this problem in this code: Private Sub NavigateRecords()
TextBox1.Text = ds.Tables("stdDataSet").Rows(inc).Item(0)-error msg appeared here sayin null reference evception was unhandled. Object reference not set to an instance of an object.
TextBox2.Text = ds.Tables("stdDataSet").Rows(inc).Item(1)
TextBox3.Text = ds.Tables("stdDataSet").Rows(inc).Item(2)
TextBox4.Text = ds.Tables("stdDataSet").Rows(inc).Item(3)
[Code]...
Public Class Inventory
Public Property Productcode As String
Public Property lstattribute As List(Of Attribute)[code]....
I have a list of inventory items.I am trying to get the max count of attributelist in the inventory list .I used this code
oLsInventory.OrderByDescending(Function(c) c.AttributeList.Count).FirstOrDefault().AttributeList.Count
But if my attribute list null. The lambda throws null reference.Is there any way to check for null reference in lambda ? Or is there a better way to rewrite the above linq query ?
write know i am gettin null reference exception due to followin code
Imports System.Xml
Imports System.IO
[code].....