DropdownList: SelectedValue does nothing.

 I have a ComboBox set as a DropDownList, and the SelectedValue property, which ostensibly will find and select the selected value, does not.

cbSalesman.SelectedValue = salesman;  This is probably because you would need to give it not just a string to look for, but an actual object that is a member of the Items list.  That would require ugly gyrations along the lines of the following.

1. get the string to look for
2. get the index of that string in the dropdown (using Items.IndexOf)
3. grab the item at that index
4. feed it to the "SelectedValue" property.

Instead of all that, why not just do this.

cbSalesman.SelectedIndex = cbSalesman.Items.IndexOf(salesman);


...

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Operation is not valid due to the current state of the object.

App Details:

Visual Studio 2010
Desktop Winforms App
MDI Child form with a Datagridview connected to SQL Server 2008

Error details:
When closing the form, debugger jumps to this line in form.designer.cs (one of the files you are not supposed to edit).

/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
    if (disposing && (components != null))
    {
        components.Dispose();  //<<<---error points here
    }
    base.Dispose(disposing);
}

and here is the massive error...

System.InvalidOperationException was unhandled
  Message=Operation is not valid due to the current state of the object.
  Source=System.Windows.Forms
  StackTrace:
       at System.Windows.Forms.DataGridViewCell.GetInheritedStyle(DataGridViewCellStyle inheritedCellStyle, Int32 rowIndex, Boolean includeColors)
       at System.Windows.Forms.DataGridViewCell.GetPreferredWidth(Int32 rowIndex, Int32 height)
       at System.Windows.Forms.DataGridViewColumn.GetPreferredWidth(DataGridViewAutoSizeColumnMode autoSizeColumnMode, Boolean fixedHeight)
       at System.Windows.Forms.DataGridView.AutoResizeColumnInternal(Int32 columnIndex, DataGridViewAutoSizeColumnCriteriaInternal autoSizeColumnCriteriaInternal, Boolean fixedHeight)
       at System.Windows.Forms.DataGridView.OnColumnGlobalAutoSize(Int32 columnIndex)
       at System.Windows.Forms.DataGridView.OnColumnCommonChange(Int32 columnIndex)
       at System.Windows.Forms.DataGridViewCell.OnCommonChange()
       at System.Windows.Forms.DataGridViewComboBoxCell.set_DataSource(Object value)
       at System.Windows.Forms.DataGridViewComboBoxCell.DataSource_Disposed(Object sender, EventArgs e)
       at System.EventHandler.Invoke(Object sender, EventArgs e)
       at System.ComponentModel.Component.Dispose(Boolean disposing)
       at System.Windows.Forms.BindingSource.Dispose(Boolean disposing)
       at System.ComponentModel.Component.Dispose()
       at System.ComponentModel.Container.Dispose(Boolean disposing)
       at System.ComponentModel.Container.Dispose()
       at Onesource.MaterialReceiptsEntry.Dispose(Boolean disposing) in P:\Projects\myproject\sample\MaterialReceiptsEntry.Designer.cs:line 18
       at System.Windows.Forms.Form.WmClose(Message& m)
       at System.Windows.Forms.Form.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DefMDIChildProc(IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at System.Windows.Forms.Form.DefWndProc(Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.Form.WmSysCommand(Message& m)
       at System.Windows.Forms.Form.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DefMDIChildProc(IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at System.Windows.Forms.Form.DefWndProc(Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.ContainerControl.WndProc(Message& m)
       at System.Windows.Forms.Form.WmNcButtonDown(Message& m)
       at System.Windows.Forms.Form.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at Onesource.Program.Main() in P:\Projects\myproject\sample\Program.cs:line 19
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

The solution:
I was looking through the ugly error stack above and found a lot of references to stuff like GetPreferredWidth. Having previously dealt with numerous problems involving AutoSizeColumnsMode and DataGridViewComboboxColumns,   I decided to try testing the form with AutoSizeColumnsMode set to None.  The layout did suck, but the form stopped crashing...

This means that the datagridview is trying to resize its columns during a form close!  Here is what I did to solve the problem.

I set the AutoSizeColumnsMode to AllCells and added a FormClose event as follows...




private void MaterialReceiptsEntry_FormClosing(object sender, FormClosingEventArgs e)

{

myDataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.None;

}

This ensures that the grid will not be updating its column sizes as the form is closing.

...

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Case Schizophrenia and the DataGridViewComboboxColumn

So by default SQL Server (Microsoft) creates indices* and  does searches that are case insensitive.

Select * from orders where salesrep='bob' Will find BOB, bob, bOb, etc. (but not Robert)

So I have a DataGridViewComboboxColumn for that field, but since the data all comes from Paradox, where anything goes, I have a mixture of case scenarios.

As it turns out, even though your database cares not what capitalization you use, the combobox does.  It WILL NOT MATCH a field that has an alternate capitalization of whats in your data.

Example: if you have DONNA in the lookup list, and Donna in the orders table, the dropdown will display SOME RANDOM OTHER NAME.

It also throws a dataerror that looks like...

Order Entry [OrdersGrid]: Row 2 Column 16 Context Formatting, PreferredSize... System.Windows.Forms.DataGridViewDataErrorEventArgs DATA: TONYA 

...and it throws this error for each and every row you attempt to display on the screen.

The solution?

All I did was load the Purchase Orders table using the salesman as its own lookup.  like this

update Purchase_Order set Salesman=(select Salesman from Salesman S where S.Salesman=Purchase_Order.Salesman)

So, we're looking up the salesman, say "Bob" in the Salesman lookup table (finding, say "BOB") and writing that back over the Bob in the row, essentially updating the names in such a way as to match exactly what's in the lookup table.

Now our DataGridViewComboboxColumns work, and we didn't even have to edit the program!




...
* I still can't make myself use the word indexes.

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Microsoft Lies

Ok, I joined the Microsoft Partner network so I could get Visual Studio 2010 (back when that was a new thing).  It was a good deal, but before I signed I called in and asked specifically if I could continue to use the software if I decided not to renew my partner network membership.

The answer was yes.  My memory is not fuzzy on this because that was the key upon which my decision to join depended.  So I signed up.

Fast forward to this morning.  I need to move my Visual Studio to a new machine.  The machine is up and running and all I need is...

1. a link to re-download the installer
2. my product key (which I may have somewhere in my 2010 tax box).

You'd think all this info would be readily available in my records.  So I log into my msdn account, click "My Product Keys" and...

So I called in again and got a really helpful guy named Ozzie.  And as it turns out, Ozzie will not help me move my Visual Studio to my new machine unless I shell out for a new partner membership membership for $149 or something - I couldn't quite hear the price over the call center chatter.

Now those of you who know me know that I am struggling mightily in this economy.  And now apparently - even though I got a valid microsoft product without cheating, they want MONEY just to move it to a new machine!  Apparently, they want money just for me to continue using the software at all!  So apparently, when you buy something, it is not really yours!  It's theirs, you're just renting it!  They should stop calling it sales, and call it what it is.  Rentals!  They are not GM, they are Netflix!  You don't get to keep what you buy!

So now I am faced with an ethical dilemma.  Do I (apparently illegally) keep using "my" software to try and eke out a living?  Or (even though I was lied to twice) should I deactivate it and basically starve to death?

I have about -$32,000 right now, and am struggling to keep food on the table.  I CANNOT just pay them and take the hit.  Especially after they misled me!

Please, if you are considering signing up for the Microsoft Partner Network to get your hands on discount software, RECONSIDER!  That or understand exactly what you will be DENIED access to after your subscription ends.


...

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Sucky Docking in Visual Studio

Delphi always did this right.  Even back in 1990.  But Some dipshit at Microsoft thought this would be the perfect way to make controls dock.  When you dock a binding navigator to the top of your panel or form, and then a Datagridview to "fill", Microsoft thought this is what you'd have in mind.

 Even the little box that pops up seems to show it correctly.

Whatever the case, I must now use a splitter - an object with tons of functionality that I don't want - to complete my layout.

Microsoft, you SUCK.

...

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

C#.NET Finding the First Day of the Week in One Line of Code

while (myDate.DayOfWeek != DayOfWeek.Sunday) { myDate = myDate.AddDays(-1); }

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Open a Web Page from C#.NET

How to easily open a web page from your C# App.

System.Diagnostics.Process.Start("http://209software.com/");

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

[INTERSOLV][ODBC Paradox driver][Paradox]Network initialization failed.

If you're seeing a...

[INTERSOLV][ODBC Paradox driver][Paradox]Network initialization failed.

... or a ...

[INTERSOLV][ODBC Paradox driver][Paradox]Directory is controlled by other .NET file.

... message, you're probably  trying to connect an ASP.NET or VS.NET Program to a Paradox database.

You've been all over the internet and there is some stuff about not being able to work on a SUBST path, but nothing you try works.  If you use the SUBST path you get Network initialization failed, while using the real path gives Directory is controlled by other .NET file.


...

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.

Incrementing a Non Numeric Index in SQL Server

So I have this client, and all his sales invoices in the old system are either numeric, or they are numeric (1000) with a single character prefix (C1000).   We want to auto increment the index automatically, but the autoincrement stuff is not going to work here.

So I wrote a function based on this SQL.

select 'C' + isnull(cast(1+max( cast(SUBSTRING(Invoice_no,2,99) as int)) as varchar),'1000')
from Sales where Invoice_No like 'C%'

Let's work from the inside out.

1. Invoice_no is the column to increment.  ('C1234')
2. first we substring the first character off with SUBSTRING(Invoice_no,2,99) ('1234')
3. we use cast to find the integer of it (1234)
4. we use 1+max to aggregate (find the max value of this integer) and add one. (1235)
5. we cast the result back to a varchar ('1235')
6. then - if isnull gives us a nulll, we use the hard-coded value of '1000'
7. we prepend the 'C' back on  ('C1235')

Now we make this into a function so we can use it like "GetDate()" in the default value of the column.

ALTER FUNCTION [dbo].[NextSalesID] ()

RETURNS varchar(10)
AS
BEGIN
    DECLARE @Answer varchar(10)   
    select @Answer= 'C' + isnull(cast(1+max( cast(SUBSTRING(Invoice_no,2,99) as int)) as varchar),'1000')
    from Sales where Invoice_No like 'C%'
    RETURN @Answer
END

 Now we have to add it as the default value for our column.  This is accomplished by editing the table in SQL Server Management Studio, selecting the column, and...

Binding a scalar Function to a Column Default

MAKE SURE that management studio doesn't add quotes '' around your function name.

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Bryan Valencia is a contributing editor and founder of Visual Studio Journey.  He owns and operates Software Services, a web design and hosting company in Manteca, California.