DataGridView automatically adds new row - why?

Question

Hello I have an older C# application using Windows Forms was written quite poorly. I recently had to make some extensive changes in the app, and now I'm facing quite strange problem.

The application was first designed to load data in main windows OnLoad method (terrible idea, I know) and later refactored to load data in another thread unobtrusively. The application makes use of BindingListView (http://blw.sourceforge.net/) which is quite straightforward implementation of IBindingListView interface.

Before the changes I made to application everything worked fine. Application started with all data loaded and there was not any problem (ommiting bad user experience when waiting for app to load data).

But when I changed the application to load data dynamicly in another thread (the grid is first displayed empty and later the data are loaded to it), there started to pop up some empty rows, which were not in the ObservableCollection bound to the grid.

I managed to track the new added rows to this call stack:

     Equin.ApplicationFramework.BindingListView.dll!Equin.ApplicationFramework.AggregateBindingListView<BusinessLogic.DataEntries.TrackEntry>.AddNew() Line 295 C#
    Equin.ApplicationFramework.BindingListView.dll!Equin.ApplicationFramework.AggregateBindingListView<BusinessLogic.DataEntries.TrackEntry>.System.ComponentModel.IBindingList.AddNew() Line 1617 + 0x8 bytes  C#
    System.Windows.Forms.dll!System.Windows.Forms.BindingSource.AddNew() + 0xbd bytes
    System.Windows.Forms.dll!System.Windows.Forms.CurrencyManager.AddNew() + 0x26 bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.DataGridViewDataConnection.AddNew() + 0x86 bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.DataGridViewDataConnection.OnNewRowNeeded() + 0x24 bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.OnRowEnter(ref System.Windows.Forms.DataGridViewCell dataGridViewCell = null, int columnIndex = 0, int rowIndex = 0, bool canCreateNewRow, bool validationFailureOccurred) + 0x10a bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.SetCurrentCellAddressCore(int columnIndex = 0, int rowIndex = 0, bool setAnchorCellAddress, bool validateCurrentCell, bool throughMouseClick = false) + 0x59f bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.SetAndSelectCurrentCellAddress(int columnIndex = 0, int rowIndex = 0, bool setAnchorCellAddress, bool validateCurrentCell, bool throughMouseClick, bool clearSelection = true, bool forceCurrentCellSelection = false) + 0x2a bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.MakeFirstDisplayedCellCurrentCell(bool includeNewRow) + 0x66 bytes
    System.Windows.Forms.dll!System.Windows.Forms.DataGridView.OnEnter(System.EventArgs e) + 0xe0 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.NotifyEnter() + 0x20 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.UpdateFocusedControl() + 0xc6 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.AssignActiveControlInternal(System.Windows.Forms.Control value = {System.Windows.Forms.DataGridView}) + 0x54 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.ActivateControlInternal(System.Windows.Forms.Control control, bool originator = false) + 0x76 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.SetActiveControlInternal(System.Windows.Forms.Control value = {System.Windows.Forms.DataGridView}) + 0x73 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.SetActiveControl(System.Windows.Forms.Control ctl) + 0x33 bytes
    System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.ActiveControl.set(System.Windows.Forms.Control value) + 0x5 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.Select(bool directed, bool forward) + 0x1b bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.Select() + 0xf bytes
    System.Windows.Forms.dll!System.Windows.Forms.SplitContainer.SelectNextActiveControl(System.Windows.Forms.Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) + 0x2c bytes
    System.Windows.Forms.dll!System.Windows.Forms.SplitContainer.SelectNextControlInContainer(System.Windows.Forms.Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) + 0xdc bytes
    System.Windows.Forms.dll!System.Windows.Forms.SplitContainer.Select(bool directed, bool forward) + 0x65 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.SelectNextControl(System.Windows.Forms.Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) + 0x7b bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.SelectNextControlInternal(System.Windows.Forms.Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) + 0x4a bytes
    System.Windows.Forms.dll!System.Windows.Forms.Form.Active.set(bool value) + 0x11d bytes
    System.Windows.Forms.dll!System.Windows.Forms.Form.WmActivate(ref System.Windows.Forms.Message m) + 0x42 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Form.WndProc(ref System.Windows.Forms.Message m) + 0x146 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x10 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x31 bytes
    System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg = 6, System.IntPtr wparam, System.IntPtr lparam) + 0x5a bytes
    [Native to Managed Transition]
    [Managed to Native Transition]
    System.Windows.Forms.dll!System.Windows.Forms.Control.SetVisibleCore(bool value = true) + 0x333 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Form.SetVisibleCore(bool value = true) + 0x87 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Control.Visible.set(bool value) + 0x11 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason = -1, System.Windows.Forms.ApplicationContext context = {System.Windows.Forms.ApplicationContext}) + 0xe8 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x61 bytes
    System.Windows.Forms.dll!System.Windows.Forms.Application.Run(System.Windows.Forms.Form mainForm) + 0x31 bytes
    Registr optické komunikace.exe!GUI.Program.Main() Line 29 + 0x1d bytes  C#
    [Native to Managed Transition]
    [Managed to Native Transition]
    mscorlib.dll!System.AppDomain.nExecuteAssembly(System.Reflection.Assembly assembly, string[] args) + 0x19 bytes
    mscorlib.dll!System.Runtime.Hosting.ManifestRunner.Run(bool checkAptModel) + 0x6e bytes
    mscorlib.dll!System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly() + 0x84 bytes
    mscorlib.dll!System.Runtime.Hosting.ApplicationActivator.CreateInstance(System.ActivationContext activationContext, string[] activationCustomData) + 0x65 bytes
    mscorlib.dll!System.Runtime.Hosting.ApplicationActivator.CreateInstance(System.ActivationContext activationContext) + 0xa bytes
    mscorlib.dll!System.Activator.CreateInstance(System.ActivationContext activationContext) + 0x3e bytes
    Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone() + 0x23 bytes
    mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) + 0x66 bytes
    mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x6f bytes
    mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44 bytes

which makes me suspect, that the adding of the new unwanted row is somehow initiated in DataGridView alone, without explicitly written code to do it.

So my question is - can DataGridView do this? And how can it be turned off? My next question is also, how can I trace what is firing the AddNew method of BindingListView, if the DataGridView is just processing some commands issued to it earlier?

Answer 1

Set the property AllowUserTAddRows=false; or through code

myDataGridView.AllowUserToAddRows = false;