i have underneath code for databing a in memory datatable to a combobox. But no values are being shown in the combobox. I get no error. When debugging i see that the table holds the row correctly.
Dim w1 As String = "Hans"
Dim w2 As String = "van Neerven"
Dim table1 As DataTable
[Code].....
Probably a very dumb question but I have a program whereby I create and populate an in memory datatable, which I then add to a data-set. I then run a couple of updates on the dataset and need to know how to then send these updates down into the in memory datatable :Here is a mock up of the code structure following the creation and population of the table :
[Code]...
I wrote a procedure that builds a DataTable in memory using data stored on our DB2 database. The function builds a Multi-Level Bill of Materials (BoM), meaning that the data cannot simply be queried. The function works great and returns a nicely arranged DataTable object. However, I then need to query the in-memory DataTable against other tables on our server. What would be the best way to approach this problem? Should I make a DataTableAdapter for the Server tables and then build a DataView? I don't have too much experience yet with Data objects. (By the way, I looked into LINQ to DB2 and even installed IBM's addin's, but our server doesn't seem to support it at this time.)
View 6 RepliesI have a table in Access with two key fields (let's call them Item and Cust). These key fields *combined* are the primary key. So each record must have a unique Item and User combination. It can have a duplicate Item with other records, and a duplicate Cust with other records, but not a duplicate of both. Because my "primary key" is a combination of two fields, I can't make a primary key on the table in Access (it only supports one field as a primary key).
I have another table in SQLServer which also has Item and Cust, but in addition, is has several descriptive fields that give more details about the Item and Cust. I'm trying to use ADO.NET to bring in that SQL Server table and UPDATE some matching fields in Access with the descriptive fields. [Code]
I started a new project with one form, this form has two comboboxes, combobox1 has datasource (access 2007 database). When I select a value from combobox1 then it sets a datasource on combobox2. Then I click on button to show openFiledialog, it throws exception.
"Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
I am giving link to check its solution file. If I use database in access 2003 format it works fine!! [URL].
I want to filter the data that's being displayed to my datagrid once I click the combobox and select a specific value,the selected value will be the item to filter the data that I needed to be displayed in the datagrid.. I'm using a datatable,a combobox and a datagrid..here's my code
Private Sub cboView_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cboView.Click
dt = New DataTable
sda = New SqlDataAdapter("SELECT DISTINCT KPIPOSTCODE FROM KKPIGROUP", sqlcon)
sda.Fill(dt)
[code].....
Is there a dll somewhere or some place I can read a good example on how to add data from a datatable into a multicolumn combobox? Preferably to be able to stick a datagridview right into the combobox would be awesome.
View 3 RepliesI used this code:
Code:
Friend Sub PopulateCB(ByRef mycontrol As ComboBox, _
ByVal expressionSQL As String)
' DMBD is my data-handling class:
[code]...
Nevertheless, mycontrol remains empty after this.
I want to fill a combobox with the values that I have in a datatable. How can I do that? Below is the code for the population of the datatable:
[Code]...
I used this
[Code]...
Nevertheless, mycontrol remains empty after this.
I am using code similar to this to populate a combobox with items from a database. The display works fine, but when I try to get the combobox.SelectedValue it is returning a DataRowView, where I need an integer. Obviously this is becuase I haven't casted the value to an integer, but the function, CInt(cboPosition.SelectedValue) is throwing an InvalidCastException. Is there any way that I can get the ValueMember's type to be an Integer?
Dim cn As New SqlConnection(CreditDisputesLogConn)
Dim cmd As New SqlCommand("CustomersLookup", cn)
Dim da As New SqlDataAdapter(cmd)
[Code]....
How can I get an item value from a Combobox using a datatable as it's datasource? Here's my code for constructing the combobox. This code works, that's why I'm not showing it all, but I want you to know how I'm creating the combobox.
Try
query = "SELECT category_id, name FROM categories ORDER BY name ASC;"
dbCommand = New MySqlCommand(query, dbConnection)
[Code]....
I want to display what is the item you physically see in the combobox that you select.
I have some comboboxes that are binded to some fields in a datatable
is it possible to sort each single combobox without soting the datatable?
I used this
vb
Friend Sub PopulateCB(ByRef mycontrol As ComboBox, _
ByVal expressionSQL As String)
' DMBD is my data-handling class:
[Code].....
Nevertheless, mycontrol remains empty after this.
I have a combobox that is connected to a datatable with 3 columns. When i click a button i want 3 values from the selected item to be transferred to another datatable.The easiest way without any hassle to do this is via the Combobox.Text, Combobox.SelectedValue and....eyy nowhat?
View 8 RepliesI've populated my DataTable will all the results from a SQL search. Upon a button click I want to populate a combobox with all the results where a condition is met. My DataTable as a column called UserID and I want to add all results where the UserID is equal to a set value (for example 12). I can do this to add all results and I guess I could add a if statement inside this to be If Entry.Tag = 12 Then but is there a better way?
[Code]...
I have binded a datatable to a combobox, using DataSource, DisplayMember and ValueMember properties. Now I try to set the combobox to a preset value using comboBox.SelectedValue = value. Nothing happens however.
[Code]...
I'm trying to setup a form to search for data within an existing DataTable.
FilterColumnsComboBox.DataSource = WOTable.Columns?
FilterColumnsComboBox.DisplayMember = ???
FilterColumnsComboBox.ValueMember = ???
[Code]....
I could hard-code in the column names ("WO_Number",WO_CustID","CustLastName", etc...), but would prefer to pick this up dynamically (partly because I want to reuse this code later).
on a windows form i have a combobox called currency, it is populated by a table-adapter called exchan-gerate which is turn populated by a dataset called mydataset. on form load, i issue update commands to the back-end database that holds the table which populates the dataset - they work. if i look at the update to the combobox, they are not reflected until i exit and restart the app - then they're fine. further down the form load i've tried:
Me.exchangerate.Update(Me.DataSet.Currency)
Me.CurrencyComboBox.Refresh()
am i missing something silly to have the values in the combobox change and refresh at the time of the update to the database? as i said, an exit and restart of the app displays the accurate data.
I'm trying to populate the list of a combobox by binding it to a datatable. Also, I want the selected value of the combobox to be bound to an object property so that when the selected value changes, it's automatically updating the object. However it's causing an error at runtime: "This causes two bindings in the collection to bind to the same property.
Parameter name: binding" I thought binding the dropdown list to a datatable and the selected value to an object were different properties but obviously I'm not getting it right.
Code:
Private Sub PopulateSiteSelect()
With Me.PlanSiteSelect
If _Plan.PlanID <> Nothing And _User.UserID <> Nothing And _Plan.Category <> Nothing Then
[Code]....
In a combobox populated by a DataTable I am having two issues!The SelectedIndex property will not set 1. Either by integer 2. Or by FindString
[code]...
In VB 2005, I am calling a C++ DLL function that returns the address in memory and size in bytes of a jpeg image. How can I load that jpeg image directly from memory into a picture box in my VB form? I cannot afford to save it to disk first.
View 10 RepliesIm getting a problem with one of my programs I have made in visual basic.NET where it gives me a memory error when i debug the program in the IDE. the exact error is this: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt". My program basically has a few forms with text fields on that get their text values from an access database on the same hard drive. Im wondering if im doing something wrong because my program just seems to eat up memory whenever it does anything. For example I have one form that has a combobox on it and when you change the drop down list selection it retreives a few strings from the database and puts them into the relevant text boxes, if you keep changing the selection then the memory usage (in task manager) just keeps going up and up. occasionally I get the error mentioned above when debugging but in my built version of the program it throws an exception everytime the memory usage gets past 49K.
Also I noticed when debugging in the "immediate window" frame I get the following message often:A first chance exception of type 'System. Invalid OperationException' occurred in System.Data.dll...Do I need to somehow be "releasing" the memory that is used to gather data once it becomes redundant?
I am using the following code
This error occurs :
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Public Class FormRegEnumValue
[CODE]......................
QuoteSystem.AccessViolationException was unhandled Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt." Source="System.Windows.Forms"
Im designing a web browser and i continue to receive this error after going to about 3 websites it crashes with that error.
I have a BackgroundWorker object that I instantiated to perform a DB process on a background thread ansynchronously. I have event handlers for DoWork and RunWorkerCompleted. I can tell that the BackgroundWorker is disposing of itself because I added a message box into the Disposed event handler.Is it necessary to detach the event handlers to ensure that the memory is cleaned up and that there are not memory leaks?
View 1 RepliesI've noticed that every time I start a new thread in my program, the memory usage jumps about 1000k and it never goes back down. I have ensured that the thread is no longer running, and only one instance of my worker thread is ever running at a time. I am using ThreadPool.QueueUserWorkItem and ASyncOperation to get stuff done. The program starts using a Sub Main in a module that uses STAThread; I read that using STAThread instead of MTAThread makes it impossible for the Garbage Collector to get in and consider objects for garbage collection. However, when I change the STAThread to an MTAThread, the WebBrowser control in my frmMain cannot be instantiated.
I get this exception:
Code: An unhandled exception of type 'System.Threading.ThreadStateException' occurred in System.Windows.Forms.dll
Additional information: ActiveX control '8856f961-340a-11d0-a96b-00c04fd705a2' cannot be instantiated because the current thread is not in a single-threaded apartment. I do threading with the WebBrowser control, so will using MTAThread fix my problem? If so, how should I partition my code so that the WebBrowser control won't be affected by the above exception? I call the thread repeatedly with a timer (although only one instance ever runs at a time), and my program's memory usage starts at about 5000k and can jump to 300,000k+ depending on many times the thread needs to be called.
I cannot use Visual Basic 2008 at all. When I go to "new project" and choose "Windows Form Application" I get this error.I have tried multiple uninstall/reinstall with no result.A microsoft reply to this suggested that I needed: " .NET Framework 2.0 Service Pack 1 " I checked, and I did not have the .netframework 2.0 service Pack 1.
When I tried to download and install the above from Microsoft.com, the istaller said that "it was not allowsed" and I was not able to install the service pack 1.
I tried Uninstalling net framework 3.5, 3.0, 2.0 and then reinstalling .netframework 2.0 sevice pack 1; then reinstalling Visual basic 2008 express edition. At the reinstall of Visual basic 2008, .netframework 2.0 sevice pack 1 is unistalled by .net framework service pack 2.When I check the foruims for simiar problems, the formus are mostly for Visual basic 5.0, or other programs that I do not have.
Here is the programs I have installed:
Operating system: Windows XP
Microsoft .net framework 1.1
Microsoft .NET framwork 1.1 Hotfix(KB928366)
Microsoft .Net Framework 2.0 Service Pack 2
[code]....
All the security updates and hotfixes for Widows XP.
The follow code can be called about 6K times on the server it is run on then gets a out of memory error in the last catch statement. I don't see what is wrong with the code, it works well up until the out of memory..
Public Function AddUserToGroup(ByVal sSamAccountName As String, ByVal sGroupName As String) As Boolean
Try
Dim returnStatus As Boolean = True[code]......
I have two forms, Form1 and Form2. Form2 has a button to show OpenFileDialog. I call Form2 from Form1 by a button. My startUp Form is Form1. When i start debugging, i press my Form1's button to show my Form2, it shows, but when i click On Form2's Button to show OpenFileDialog it is giving me exception that
"Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
When i set my startup Form to Form2 and click Form2's Button to show OpenFileDialog then it shows!