ASP.NET Setting SelectedValue That Doesn't Belong To The List Does Not Trigger Exception
Jan 25, 2010
I have an ASP.Net form where I use a DropDownList control to display data retrieved from a table. However setting the SelectedValue of the DropDownList to a value not existing in the dropdown list does not trigger an exception.
I have a WinForms app built with VB.Net in VS 2010, and I'm scratching my head over the following issue.I have a form with a combobox which gets bound to a datasource when the form is loaded:
With Me.cboCompany .DataBindings.Clear() .DataSource = Me.m_dsBidResults.Tables("Company") .ValueMember = "company_id"
[code].....
This seems to work fine, as long as the user doesn't switch focus to some other control and then go back to the combobox. After switching focus, if the user then changes the combobox selection to the first item in the dropdown list (SelectedIndex = 0), the SelectionChangeCommitted event fires, but the SelectedValue remains set to the previously selected value. I've verified this by adding a message box in the above event handler, displaying SelectedIndex and SelectedValue side-by-side.
'add this to SelectionChangeCommitted event handler MsgBox(String.Format("Selected Index: {0}, Selected Value: {1}", cboCompany.SelectedIndex, cboCompany.SelectedValue))
This does NOT happen if the user changes SelectedIndex to anything other than 0; everything behaves as expected. I've verified that the table I'm binding to contains unique values for company_id and company_name.Do I need to use some other event to verify that the SelectedValue has actually changed?
I want to get a list of all users and groups that belong to a specific department (entered by the user) from Active Directory using VB.Net and DirectoryServices.
I have a class library in which i have created a simple new application with a form and added AX webbrowser control on it. In order to apply events on popup of webapplication shown in webbrowser (or to detect whether a pop-up has opend), i am using LostFocus event on webbrowser control, it was working fine till now.But after i reset my IE settings (Internet options->Advance->Reset) the event stopped working. I am using IE9 and the class library is developed in VB.NET (VS 2010).
I use Visual Studio 2003, VB.net, NetFramework 1.4 and Windows XP I have been using the following Code Snippet for a number of years in both Web Services and Windows Applications. However suddenly around the 29th September 2010 it has stopped sending E-Mails from both Web Services and Windows Applications. The same problem has happened not only to my own Network but on two other Networks, one using XP as its Server and the other using Server 2003. All 3 of these are using different ISPs.
I am looking to create a 500ms timer that I can use to make some text flash.Setting up the timer is straight forward enough, but I have not found an example of letting the timer create an exception so I do not have to poll it for a timeout.
I have a gridview with a dropdown list that was created programmatcially. I want to have access to the selected value and to that row's Id. I have the dropdownlist created in *Gridview_RowDataBound* and I am able to use the text in the cell but my addHandler is never fired. Where do I give it the Add handler. I believe I can assign it the addhandler in RowCreated but how would I be able to set up the add handler if the button is created in rowdatabound?
[Code]...
It fits best in Rowdata bound because my dropdownlist items don't duplicate but I need to be able to use the addhandler I created.
I have a main form that has a dynamically generated treeview and also a panel control. Depending on the selection made within the treeview the panel docks 1 of three diffrent usercontrols which are full sub forms(done for ease of modifing design of sub form rather than layering panels on top of panels).Upon button click withing usercontrol i wish to trigger event within main form.For example delete button wich then triggers to remove current selected node from treeview. code for 1 of three diffrent user controls
Dim ctrlQ As New QuoteUC(TrViewQuotation.SelectedNode) PnlSubFormDock1.Controls.Add(ctrlQ)
Code for delete button for which i need to raise event.
If MsgBox("Are you sure you wish to delete this customer ?", vbYesNo, "Delete Record") = vbYes Then Deletecustomer(n) End If
So I have a program that I am converting to .NET FW 3.5 and I am getting the titled exception on the following line:If IsNothing(dsTopPI.Rows.Find(profile.Item("GEMSID"))) Then Continue For
which is in a for each loop. The thing is, I have set the primary key and when I put in the following code:Dim columns() = DSTop30Profiles1.DTtop30profiles.PrimaryKey Console.WriteLine("Column count: " & columns.Length.ToString)For a = 0 To columns.GetUpperBound(0)Console.WriteLine(columns(a).ColumnName & " - " & columns(a).DataType.ToString)Next
I get this in the output:Column count: 1 GEMSID - System.Int32
That would seem to indicate that there is in fact a primary key, right?
i have to develop a software for motorola mc9090 that reads barcodes and rfids simultaneously, so i need to catch two different triggers: the one on the keyboard for barcodes and the other in the backside for rfids.the problem is that i didn't find any sample that illustrates how to set the trigger to read only barcodes, i found something on emdk 2.5 samples that shows how to set the trigger to read rfids but nothing for barcodes. So when i press any trigger the barcode reader is always enabled with rfids reader.Does exist a way to manage them with separated triggers?
Note: this is not a duplicate of Jeff's question. That question asked "Is an equivalent?" I know there isn't, and I want to know why! The reason I ask is that I've only just become clear on how important it is, and the conclusion seems very strange to me. The Exception Handling block of Microsoft's Enterprise Library advises us to use this pattern:
[Code]...
The policy is defined in an XML file, so that means that if a customer has an issue, we can modify the policy to assist with tracking down (or perhaps papering over) the problem to give them a fast resolution until we deal with it properly - which may involve arguing with 3rd parties, about whose fault it all is. This is basically an acknowledgement of the simple fact that in real applications the number of exception types and their "recoverability" status is practically impossible to manage without a facility like this.
Meanwhile, the CLR team at MS says this is not an option, and it turns out those guys know what they're talking about! The problem is that right before the catch block runs, any finally blocks nested inside the try block will be executed. So those finally blocks may do any of the following: Harmlessly modify the program state (phew, lucky). Trash something important in the customer's data, because the program state is screwed up to an unknown degree. Disguise or destroy important evidence that we need to diagnose an issue - especially if we're talking about calls into native code. Throw another exception, adding to the general confusion and misery.
Note that the using statement and C++/CLI destructors are built on try/finally, so they're affected too. So clearly the catch/throw pattern for filtering exceptions is no good. What is actually needed is a way to filter exceptions, via a policy, without actually catching them and so triggering the execution of finally blocks, unless we find a policy that tells us the exception is safe to recover from. The CLR team blogged about this recently:
Usually when I get an exception, the code line that creates it is marked yellow etc.. However now i only get a System.NullReferenceException as a line in the Immidiate window;
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
Is this due to some setting, or why don't I get any better indication?
I have creating timekeeping application, I was used drag and drop for my datagridview. During build I can add, edit and delete records. But when I published and run there was an error saying (see below). [Code] When JIT debugging is enabled, any unhandled exception, will be sent to the JIT debugger registered on the computer, rather than be handled by this dialog box.
What is going on with my code. To .NET and handling SQL connections. I am trying to catch an error where lets say someone puts in something that violates the rules of the field (i.e. they put data in a field that doesn't matched what is on the other table.) Please find teh code I ahve put on the save button to try to catch the error. Instead of popping a message box up the program just closes itself.
Private Sub Job_tableBindingNavigatorSaveItem_Click_2(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Job_tableBindingNavigatorSaveItem.Click Try
The exception message I am receiving is this... "Year, Month, and Day parameters describe an un-representable DateTime."
Now I've traced my values being passed and everything is correct. Values loops through 1 to 12 but still I continue to receive an exception. Only way I can avoid this is by throwing a Try, Catch statement around where I'm passing over the value.
Here's my code..
001 Dim Calendar(11) As AppointmentBookControl.AppointmentBookControlMonthlyOverviewCalendarControl 002
[Code]....
Line '011 .Month = i+1' is where the problem is located. The values for (i+1) maintain within the bounds of 1 through 12..
I am trying to get an index of a List(Of Details) Details being a class i use instead of an annon method. Is it because i am using array.findindex when it's not an array but a list(Of???
Dim index As Integer = Array.FindIndex(Details, Details.FirstOrDefault(Function(nd) nd.Name = "name")) Error1Data type(s) of the type parameter(s) in method 'Public Shared Function FindIndex(Of T)(array() As T, match As System.Predicate(Of T)) As Integer' cannot be inferred from these arguments. Specifying the data type(s) explicitly might correct this error.
I have a BindingList of transactions that I am binding to a DataGridView. The client now wants each row to have a sequential number. (1,2,3, etc).There could be hundreds of transactions. So is there an efficient way to assign a sequential number to each item in the bindingList?I know I could For/Next through and manually assign an incrementing index. But I am concerned about the performance when we process lots of transations.
I have added a .jpg file to the resources folder in my project. I then added the file as a resource so it shows up under the resources folder in the Solution Explorer. However, when I go to call the resource file in my code it doesn't show up in the list of available resources. Here is what I am trying to do:
I have a routine in a custom class that is assigning values to an object based on data from a table row. However, several tables may be used to update these values and only have some of the fields in common. Therefore, I want to check each field value to make sure it exists before I attempt to access it's value to assign to my object. However, I am getting the error "Column x Does Not Belong To Table."
'error occurs on first line If Not memberRow.Item("nickname") Is Nothing Then returnval.NickName = Trim(memberRow.Item("nickname").ToString) End If
I want to know what's the right way to work with objects that belong to a category.I'm building an applications with the following layers:Base data access Data access Business logic + Factories Presentation.I want to pass only objects to the presentation layer and back.I have objects (Employees), that belong to a certain category (EmployeeCat). I was wondering if I should have just an EmployeeCatID property in my Employee class/object, or an EmployeeCat property that contains a complete category object.If I want to fill a GridView with a list of employee objects as datasource, and I used just an ID in my Employee objects, then I will have some work at the presentation level to display the category names, so I think. On the other hand, if the list of employees contains plain category objects... I'm not sure what will happen.
I got some simple sql statement to see a record but I get an error - column does not belong to table...
Here's my
Dim mydataset As New DataSet mystring = "select max(NoteRef) as max_NoteRef from notes" Dim adapter As New SqlDataAdapter(mystring, nwindconn) adapter.Fill(mydataset, "notes") Label1.Text = mydataset.Tables(0).Rows(0).Item("NoteRef")
The ListBox gets populated correctly. After it is populated, i have a CommandButton and on the click event of the button, i want to remove selected items from the ListBox. So in the click event of the CommandButton, i have written the following code:
lstItems.Items.Remove(lstItems.SelectedItem)
After selecting an item from the ListBox and when i click the CommandButton, i get an error as "Items collection cannot be modified when the DataSource property is set".
Within Control Panel -> Regional and Language Options, there is a Formats tab, with a drop down of all possible language formats. I wish to retrieve this list using VB.NET. Could anyone point in the direction of which Windows API call to use?