I was working with a class used to update database.All things were working for 3 years perfactly.Now it started throwing exception for two records only.When i edit these two records and try to save back to db it throws exception.Else it works fine.
View 3 RepliesAt the top of my code for the form I have the following statements (and some other unrelated ones to):
Dim LastDataRow As DataRow
Public Event RowChanged As DataRowChangeEventHandler
When my form loads I run the following line of code:
AddHandler dt.RowChanged, New DataRowChangeEventHandler(AddressOf Row_Changed)
After the form loads I have a FetchData button which connects to the database and brings the records into a datatable object. During this fill operation my Row_Changed event fires (for every record I think) and tries to run DataAdapter.Update(DataTable) (pseudocode) which ultimately fails because I haven't yet created commands. The error I get in my Row_Changed procedure is:
Update requires a valid InsertCommand when passed DataRow collection with new rows.I hadn't even planned to use an InsertCommand at all since I will not be allowing users to insert records from this form. I do plan to allow them to delete or modify existing records, but not insert new ones.run my AddHandler statement after filling the datatable. However, I'm trying to figure out how to rewrite my code so that I can refresh the datatable without closing out the form/application and having to open it up again. I think that's a problem for a separate discussion.
I use DataGridView in my project. Everything worked fine until I added some code in the RowValidating event. During the form_load event exception is thrown on the statement that set the datasource of the DataGridView.The project uses bindingsource for the datasource of the DataGridView. My validating code is shown below:
Dim currentRow As DataGridViewRow = Me.dgExpenditure.Rows(e.RowIndex)
Dim incexpCell As DataGridViewCell = currentRow.Cells(0)
If Not Me.closingBoolean Then
[code]....
I debated whether or not to ask in the database section, but decided this was probably more of a VB question, than DB.I'm performing a query on my database and add its value to a DGV. At the moment, I'm just running tests to make sure the base example works so I can expand on it for more advanced tests.[code]It doesn't matter how I add the row, just adding it causes the error. And yes, the AllowUsersToAddRows property of the DGV is set to True, which wouldn't cause this problem anyway, but I decided to be extra careful.
View 1 Repliesi want to run a query and use the result for something else in my vb.net code. I have, opened the connection, passed the query and the connection object to the SqlCommand object and read it with the datareader object. The DataReader's HasRows property's value evaluates to true but i get an InvalidOperationException when i want to access the results of the query with the DataReader.[code]
View 1 RepliesI'm having an issue with updating a couple list boxes in the form load procedure. I have an array created from a MySQL database, and when I try to add that array to more than one ListBox, I get: A first chance exception of type 'System.ArgumentNullException' occurred in System.Windows.Forms.dll
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I'm getting a "IndexOutOfRangeExeption was unhandled" in my project
Private Sub LookUpButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LookUpButton.Click
'Look up the information on the state.
[Code].....
I'm about ready to give up and go another route. I just thought I'd ask here.
For Each ScreenName As String In da.settings_LinkedScreenNames
View 5 RepliesI have the following method to strip hidden and user-specified columns from a gridviewrow and return a tablerow. [Code] However, when I run this code and hit the Add method for the TableRow, I get an InvalidOperationException stating the Collection was modified; enumeration operation may not execute. I've gotten this exception before, but usually it's because I'm attempting to modify a table that is databound.
View 3 RepliesI am trying to show a dialog from one of my WPF view model commands however when i call ShowDialog() it throws a System.ArgumentException?
Here is my code:
Public ReadOnly Property OpenParser As ICommand
Get
Return New RelayCommand(Sub(param As Object) OpenParserExecute(DirectCast(param, Frame)))
End Get
[code]....
I remove the datagridviewcomboboxcolumn from the datagridview and dispose it. When I go to dispose of the datatable that is the datasource to the comboboxcolumn an ArgumentOutOfRangeException is thrown from the datagridview. Apparently the datagridview is still handling events for datagridviewcomboboxcells for comoboboxcolumns that have been removed from the datagridview.
View 8 Repliesi am writing a program that will store some passwords in order to make it more user friendly. Ofcourse i want to encrypt it and so i started to learn how to use the 3Des encryption method.
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i am trying to develop a simple app to automate binding of data from access db for filling a form in a sequential order vb 2008 express. an error keeps coming up 'expression expected' on an sql query in the code i wrote. the code is shown below:
Private
Sub STARTButton_Click(ByVal
sender As System.Object,
ByVal e
[code]....
I'm getting this exception in the designer when I try to look the form that contains the tab control in design mode. After I click OK, the designer simply shuts down
View 1 RepliesVB2008 (in VisualStudio) and automation of tasks in Excel. My work env.: PC#1 - WinXP Sp3 with VisualStudio & Office O27k (all US-EN) installed, PC#2 - when I am not at home I use an Laptop with WinXP + O27k (DE) and VisualStudio(US-EN), but the mix of language does not seem to be a problem - at least until now!
In one 'TestBench' appl. I have the following line of: oWB.Names.Add("DR_AppData2", RefersToR1C1:="=OFFSET(AppData!R3C1,0,0,(COUNTA(AppData!C1)-2),1)")
Where 'oWB' is a WorkBook Object and 'Names' refers to named regions in an Excel worksheet. I am adding a new 'Region': DR_AppData2 and assigning a dynamic number of rows.
The above line works perfectly well on 'PC#1' but throws an exception on 'PC#2' and this has really irritated me, and I find no reason for this behaviour! The Project environment and included references / resources are truly identical, because I copy the project data from one to the other. The only real difference is in the object library reference, on 'PC#1' Excel.exe is in English, and on 'PC#2' is in German. Having said that I have also altered the value assigned in : "RefersToR1C1:=" to the equivalent in German, but the error thrown is the same.
I have attached :
1. Screenshot of the error
2. Exception Details
I am trying to send E-mails asynchronously and it works fine as long as there isn't an AlternateView attached to the e-mail. When there is an alternate view, I get the following error:
Cannot access a disposed object. Object name: 'System.Net.Mail.AlternateView'
System.Net.Mail.SmtpException: Failure sending mail. ---> System.ObjectDisposedException: Cannot access a disposed object.
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I have done a access setting in registry in HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerSettings. Here i have given no access to the "Setting" and when i try to create a linklable in windowform i am getting exception. Ex:
The control System.Windows.Forms.LinkLabel has throw an unhandled exception in the designer and has been disabled. Exception: Requested Registry access is not allowed.
Stack trace:
at System.Windows.Forms.LinkLabel.get_LinkColor()
Exception Text:
System.Security.SecurityException: Requested registry access is not allowed.
at System.ThrowHelper.ThrowSecurityException(ExceptionResource resource)
at Microsoft.Win32.RegistryKey.OpenSubKey(String name, Boolean writable)
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I'm calling Sqlcommand.ExecScalar() - stepping through the stored proc works fine, right under
RETURN @RecordNum
@RecordNum correctly contains a bigint, as scoped. When I step into the RETURN.. I get an exception thrown, that visual studio does not seem to be able to capture.
The stored procedure works fine when executed directly, and returns a value without problem, and it seems like all is well, stepping through it from my code.
But as soon as I step into 'RETURN @RecordNum' (and recordnum contains a valid number..) BOOM! EXCEPTION! (and no details in the exception either back in visual studio.
I'm blaming a glitch in the matrix.
I've turned off even assigned the return from the ExecScalar to anything, same result.. I've tried ExecReader(), same result. I have turned NO COUNT on and off, same result. If I wasn't already bald, I would be now!
Goal: Load a validated xml file in to memory, traverse through the document to create objects and load object properties with values in named xml tags.Problem: How do I deal with missing tags?Amplifying information: in this example, there are three values I'm looking for; name (mandatory), location (optional), comments(optional). I found the problem in prototyping the solution. My inital test was with an xml file wtih all fields present. It works fine as long as I don't have nanespace declarations in the root element. However, if I leave them in place I get a null reference exceptoin. The same thing occurs if I leave off an optional tag. It appears that if the Element I'm trying to get a value on doesn't exist within that element, a null reference exception is thrown.
Code:
Private Sub btnImport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnImport.Click
Dim xelement As XElement = xelement.Load(txtXMLfileLoc.Text)
Dim ICAOxs As IEnumerable(Of XElement) = xelement.Elements()
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Okay, so I wrote a few custom ItemTemplates for VS2010 that implement IWizard in VB.NET (4.0). Straight forward enough. They work during my testing, but when someone else deploys and attempts to use any of them, Visual Studio throws an incredibly generic Exception has been thrown by a target of invocation error.
Stranger still, after they open up the project properties and try again... they work. Without changing anything. Anyone have any clue what is going on? Or perhaps even just a way of getting VS to give me a more specific error? I already tried devenv.exe /log but nothing out of the ordinary was there.
I've got a code sample below that will compile, but not run. Start it in the debugger by clicking the "step into" button on the toolbar, and an exception pops up before it reaches the first line of user code:
"Could not load type 'TestPrivileges.Win32Module+TOKEN_PRIVILEGES' from assembly 'TestPrivileges, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'."
Comment out either the 'Dim ... TOKEN_PRIVILEGES' line in the module or the 'Public Shared ... TOKEN_PRIVILEGES' at the end of the class, and the problem will stop occurring.Visual Studio 2008 as well as 2010 does it.
Module Module1
Sub Main()
Dim newState As Win32Module.TOKEN_PRIVILEGES = New Win32Module.TOKEN_PRIVILEGES
MsgBox("Here I am")
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I am using .net 2.0 and I am getting an exception of system is out of memory. My existing function takes datatable as input parameter which contains little bit large data (eg. more than 35000 rows) and in that function I am appending some xml node data and atlast I am returning the stringbuilder as a object.
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Error: System.Runtime.InteropServices.COMException (0x800A03EC): Exception from HRESULT: 0x800A03EC is thrown after execeution of Microsoft.Office.Interop.Excel.ApplicationClass.set_Calculation(XlCalc ulation RHS)
Out of nowhere COM start throwing exception when I set change excel's Calculation property. Line of code that followed set_Calculation was.Workbooks._Open. This used to cause exception every second try. Than I changed order, first open workbook and than set calculation property. Amount of exceptions start decreasing than I added thread.sleep(200) and exception is not thrown anymore. This happens only on one some of user machines while others are fine.Application itself is single threaded so this delay should be of importance if and only if set_Calculation is executed asynchronously. What I'm missing here?
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I have been researching all that is related to DataSources, DataReaders, DataAdapters, etc, with an Access 2010 DB bound to a DataGridView.
Everything is fine, just one line fails and is driving me nuts Here is the code:
[Code]...
The line that fails, actually updates my database, but somehow, the update is not performed on the line that belongs to the first row of the grid. What is more, if I change the value manually, the same update method works fine. What is going on here?
I dont know where's my error.To begin with i have two buttons ADD and SAVE.My Datebase Name is COURSE where all its fields are text except courseid (number).when i click SAVE the only error is FAILED to convert parameter value from a string to Int32 exactly during dataadapter.update (ds,course)I am not converting any datatype or value to int32 .
Private Sub BUTTONSAVE_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BUTTONSAVE.Click
MsgBox(" SAVING CHANGES....")
Me.Cursor = Cursors.WaitCursor
[code]....
I need to select some user datagridview settings (such as column width, column visible, etc.) from my database. Then I run a loop to change those settings. If any settings are changed I need to update the database. For some reason I can't get the code below to update anything. The code throws no errors when it executes, but when I check the database for the updates nothing is changed.
Public Sub pubsub_UpdateUserSettings(ByVal FormName As String, ByVal dgv As DataGridView, ByVal MethodID As Integer)
Dim adt As New SqlDataAdapter
Dim cmd As SqlCommand
Dim cmd2 As SqlCommand
Dim dt As New DataTable
[Code] .....
I am trying to make a little search system, so the user can enter a search parameter which then populate a DataAdapter, DataSet then DataGridView with the selected data then any change the user makes in the DGV are then commited to the MS Access (97) Database when a Update Button is pressed. This is what i have so far, at the minute it seems to populate the DA, DS and DGV but when i come to press the Update Button I get a pop up box with a long error message:
Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click
connetionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " & frmMain.varDP_System
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I am trying to update a DateTime object into a datetime field of a sql (SQL Server 2000) database.I have the following function
Public Sub Update(ByVal lastlogin as DateTime)
Using slqupdate as SqlCommand = _connection.CreateCommand()
sqlupdate.CommandType = CommandType.Text
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I am using SQL Compact Edition and have a textbox binding to a dataset. When I enter something in the text box and try to update the datasource I get that the column Code in the datasource cannot be null. The textbox has a value so why is Code null?
Dim CONN_STRING As String = "Data Source=" & My.Settings.AutoCallPath & ";Persist Security Info=false;"
conn.ConnectionString = CONN_STRING
Dim myCommand As New SqlCeCommand("SELECT * FROM AutoCallDataTable", conn)
da.SelectCommand = myCommand
[code]....
I have an application to re-sequence some items based on a an alphabetical ordering of the items from another table. I couldn't create an update statement to update the database when I pulled the information by a join query, So I pulled down both tables into a dataset with an XML Schema description where the two are related by the itm_id key as in the database. I then have two datagrids one with the items and one with the bound to the relationship this allows only the records associated with the itm to be displayed in the datagrid, I then run a loop that changes to sequence number for each corresponding record,this all works fine but then I go to update the back end database.
The update from the dataadapter executes successfully, but then if I reload the dataset from the database back end I find that the update did not actually update the records on the back end. The only record that was updated was the very first record which updated with a 0 then all the others did not take, I have re-run it several times and they will not take.
Me.Cursor = cursors.WaitCursor
odbaCatItem.MissingSchemaAction = MissingSchemaAction.AddWithKey
odbaCatItem.SelectCommand = odbsCatItem
[code].....