Archive for the ‘.NET’ Category.

Real world Conference data & a Windows Phone App! (CONDG meeting, December 8, 2011)

Samidip Basu gave a very informative presentation on OData as it applied to the Columbus M3 Conference that took place in November of 2011, and how he put together a Windows Phone app that consumed the Azure hosted data.

As it was at the December CONDG meeting two years ago, I won a totally crappy T-shirt, and gave it to a former co-worker. Which made the evening that much more successful.

BTW, Happy Birthday to the Petrified Forest National Park, established this day in 1962. The petrified logs and the Painted Desert are fantastic, I highly recommend a trip there.

How to Move Your App to the Cloud (CONDG meeting, June 23, 2011)

Brian Prince gave a presentation on Windows Azure at the Central Ohio .NET Developer Group meeting on June 23, 2011. The presentation was mostly talking the process of moving existing applications to Azure, and the pitfalls that can arise when doing so. It was a very interesting presentation, and very appropriate since the company I am now working at is looking at creating some cloud based services.

BTW, Happy 99th Birthday to Alan Turing. OK, he is not currently among the living, but Happy Birthday to him nonetheless.

Continuous Integration: More than just a toolset (CONDG meeting, March 24, 2011)

Jay Harris gave an excellent talk and demo on continuous integration at the Central Ohio .NET Developer Group meeting on March 24, 2011. The presentation was mostly talking about the concepts and pitfalls of continuous integration, but he did run through a quick installation and demo of a free continuous integration tool, and the demo gods smiled on Jay as it went pretty well.

Also, Shawn Wallace gave a quick presentation on the mysterious world of branching and merging, a subject that does not get nearly the attention that it deserves at most software companies.

On a personal note, my name was drawn as the first name on the door prizes, which meant that I could choose one of three unknown prizes. Of course, having the first choice, I drew the lemon of the lot (Windows Vista Ultimate, joyous day) and was embarrassed in front of the group. The second name drawn, a former co-worker of mine, also chose one of the unknown prizes, and got the best of the lot, a Microsoft Arc mouse. Oh well.

BTW, happy birthday to Steve Ballmer.

Don’t try, don’t catch

Have you ever had a situation where all of those nested try/catch blocks just get in your way when trying to chase down a problem? I just hate that.

Luckily, in Visual Studio 2008 (and other versions, I am sure), there is a handy dandy way to disable all of the try/catch blocks when you run the application in debug mode from the IDE.  Just go to the Debug menu, select Exceptions, click the box under the Thrown column for Common Language Runtime Exceptions (or others if that is what you are looking for), and click OK.  Now when the code has a problem, you see it right away instead of trying to work backwards through nested try/catch blocks in different classes and modules.

Just don’t forget to put it back to the way it was when you are done. I am not a huge fan of try/catch blocks, but their normal use definitely has its place.

Is this string numeric?

This VB code was brought to my attention.  It is meant to look at a string variable (prefixText) and decide if the string is numeric or not, and return a data set (ds) by using a different method based on the result of the numeric test. (As always, this code is in a heavily used production environment.)

If Left(prefixText, 1) = "0" Or Left(prefixText, 1) = "1" Or Left(prefixText, 1) = "2" Or Left(prefixText, 1) = "3" Or Left(prefixText, 1) = "4" Or Left(prefixText, 1) = "5" Or Left(prefixText, 1) = "6" Or Left(prefixText, 1) = "8" Or Left(prefixText, 1) = "9" Then
    ds = New Users(_ConnStr).getUsersListByNumber(prefixText)
Else
    ds = New Users(_ConnStr).getUsersListByLastName(prefixText)
End If

I have some great ideas on how to improve this code. The first thing I would have done was to use OrElse instead of Or, it would speed things up tremendously. And I would also have added in the test for the “7″ character.

2010 Central Ohio Day of .NET

A co-w0rker and I attended the Central Ohio Day of .NET on June 5, 2010. There was quite a bit of good content at the conference, which is a real tribute to the organizers, volunteers, and presenters.

The highlights of my day were sitting in on Matt Casto’s regular expressions talk, Phil Japikse’s M-V-VM primer, discussing the etymology of the MongoDB project with Sam Corder (I still say it was named such after the character in Blazing Saddles), Michael Eaton’s talk on WPF, and Parag Joshi’s demonstration of XNA/Windows Phone 7 game development.

VB.NET Printing For Dummies

In order to send stuff to the printer in VB.NET, it is not quite as simple as dealing with the Printer object as in VB6. There are a couple of extra steps involved. Here is what I found, along with some helper methods that you might find useful.

On the form you want to print from, pull up the Toolbox and add a PrintDocument, a PrintDialog, and a Button, set the Document property of the PrintDialog to point to the PrintDocument you just created, and in the button’s Click event, insert the following code:

    Private Sub butPrint_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butPrint.Click
 
        If PrintDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
            PrintDocument1.DefaultPageSettings.Landscape = True
            PrintDocument1.Print()
        End If
 
    End Sub
 
    Private Sub PrintDocument1_PrintPage(ByVal sender As System.Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
 
        PrintTestPage(e.Graphics, PrintDocument1)
 
    End Sub

The Print method call in the button click event then fires the PrintDocument PrintPage event. Notice that I have set the default page settings to landscape. Don’t forget to wire the PrintDialog Document property to your PrintDocument, otherwise if you change the printer to print to in the print dialog, the document will still go to the default printer.

The PrintTestPage method is just something simple that I put together to make sure that the coordinates and justifications are all working fine. Here is that code:

    Sub PrintTestPage(ByVal g As System.Drawing.Graphics, ByVal doc As PrintDocument)
 
        Dim x, y As Integer
 
        For x = 0 To 100 Step 10
            For y = 0 To 100 Step 10
                PrintAtLocationWithColor(g, doc, x.ToString + ", " + y.ToString, x, y, _
                                         If(x = 0, "L", If(x = 100, "R", "C")), If(y = 0, "T", If(y = 100, "B", "C")), _
                                         "Arial", 8, True, Brushes.Red)
            Next
        Next
 
        PrintRectangle(g, doc, 0, 0, 100, 100)
        PrintRectangle(g, doc, 10, 10, 80, 80)
        PrintRectangle(g, doc, 20, 20, 60, 60)
        PrintRectangle(g, doc, 30, 30, 40, 40)
        PrintRectangle(g, doc, 40, 40, 20, 20)
 
    End Sub

The two methods called here, PrintAtLocationWithColor and PrintRectangle, are shown here:

    Sub PrintAtLocationWithColor(ByVal pg As Graphics, ByVal pd As PrintDocument, ByVal s As String, _
                                ByVal xPosition As Single, ByVal yPosition As Single, _
                                ByVal justification As String, ByVal verticalJustification As String, _
                                ByVal fontFace As String, ByVal fontSize As Single, _
                                ByVal fontBold As Boolean, ByVal theColor As Brush)
 
        Dim w, h As Single
        Dim x, y As Single
        Dim f As Font
        Dim sty As FontStyle
 
        sty = FontStyle.Regular
        If fontBold Then sty = sty + FontStyle.Bold
        If fontSize < 1 Then fontSize = 8.0
        f = New Font(fontFace, fontSize, sty)
 
        If pd.DefaultPageSettings.Landscape Then
            x = xPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
            y = yPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
        Else
            x = xPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
            y = yPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
        End If
 
        w = pg.MeasureString(s, f).Width
        h = pg.MeasureString(s, f).Height
 
        If Left(UCase(justification), 1) = "C" Then
            x = x - w / 2
        End If
        If Left(UCase(justification), 1) = "R" Then
            x = x - w
        End If
 
        If Left(UCase(verticalJustification), 1) = "C" Then
            y = y - h / 2
        End If
        If Left(UCase(verticalJustification), 1) = "B" Then
            y = y - h
        End If
 
        pg.DrawString(s, f, theColor, x, y)
 
    End Sub
 
    Sub PrintRectangle(ByVal pg As Graphics, ByVal pd As PrintDocument, ByVal xPosition As Single, ByVal yPosition As Single, _
                                ByVal width As Single, ByVal height As Single)
 
        Dim w, h As Single
        Dim x, y As Single
 
        If pd.DefaultPageSettings.Landscape Then
            x = xPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
            y = yPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
            w = width / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
            h = height / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
        Else
            x = xPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
            y = yPosition / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
            w = width / 100 * (pd.DefaultPageSettings.PrintableArea.Width)
            h = height / 100 * (pd.DefaultPageSettings.PrintableArea.Height)
        End If
 
        pg.DrawRectangle(Pens.Black, x, y, w, h)
 
    End Sub

All of the positioning and size parameters of these methods are percentages across and down the page, which I find much easier to deal with than absolute or printer specific positioning. This makes it dead simple to scale the reports to any page size I want to use.

.NET Kombat (Format vs. ToString)

In converting some legacy VB6 code to VB.NET, I noticed that there was a lot of use of the Format function in the code to convert numbers to strings. This makes sense as Format was pretty much the only game in town in VB6.

However, in .NET, they introduced a handy-dandy .ToString() method that, on the surface, seems to do much the same thing as the Format function. I have been able to use them pretty much interchangeably with the desired results coming out every time.

I started to wonder which way was faster. Since I am a big proponent of empirical knowledge instead of just trying to get the theoretical story behind the two ways to do this, I rolled together this quick VB.NET console application:

Imports System.Text
 
Module Module1
 
    Sub Main()
 
        Dim i As Integer
        Dim r As Random = New Random()
        Dim t As Double
 
        System.Console.WriteLine("10,000,000 Formats")
        Dim sb1 As New stringbuilder
        t = Timer
        For i = 1 To 10000000
            sb1.Append(Format(r.NextDouble * 100.0, "###0.00 "))
        Next
        System.Console.WriteLine("Seconds elapsed: " + (Timer - t).ToString("#######0.00"))
        System.Console.WriteLine("Length of string builder: " + sb1.Length.ToString())
        System.Console.WriteLine()
 
        System.Console.WriteLine("10,000,000 ToStrings")
        Dim sb2 As New StringBuilder
        t = Timer
        For i = 1 To 10000000
            sb2.Append((r.NextDouble * 100.0).ToString("###0.00 "))
        Next
        System.Console.WriteLine("Seconds elapsed: " + (Timer - t).ToString("#######0.00"))
        System.Console.WriteLine("Length of string builder: " + sb2.Length.ToString())
        System.Console.WriteLine()
 
        System.Console.WriteLine("Press any key to end the program ")
        System.Console.ReadKey()
 
    End Sub
 
End Module

And here are the results:

As you can see, the ToString method is about 15% faster when doing 10 million calls with random numbers.

Oh, and by the way, Happy Pancake Day.

Easy way to format the time difference between two dates

In converting my VB6 code over to VB.NET, I was looking for an easy way to take the different between two DateTime items and display in hours and minutes.  The TimeSpan gives a nice structure to dive into the difference and see exactly the interval, but I was hoping to find a way to output this in the same way that you can use the ToShortTimeString method of DateTime.

As it turns out, I found a posting by Jay Barlow that mentions converting the time different to a date time, and then using a custom format string to do the work so that I wouldn’t have to.  Here is my new VB.NET code, where rec is a class that includes the start and end date and duration is a string that holds the information to be displayed:

If rec.endDate IsNot Nothing Then
    Dim ts As TimeSpan = CDate(rec.endDate).Subtract(rec.startDate)
    Dim dt As DateTime = DateTime.MinValue.Add(ts)
    duration = "Event duration: " + dt.ToString("H:mm")
End If

Oh, and one more thing. Am I the only one in the world that thinks that iPad is the worst product name in history? Sure, it is so close to iPod so as to create brand recognition and draw comparisons, but I would just wonder what kind of names were shot down, and if any of them did not begin with the letter i.

By the way, Happy (Belated) Australia Day.

VB.NET radio button groups act differently than VB6 radio button groups

The few dozen remaining WinForms developers left on this planet may have noticed that, for some reason, a group box with radio buttons in it as designed in the Visual Studio 2008 environment will have the first radio button of the first group box automatically selected when the form comes up, even though all of the radio buttons have their Checked property set to false in the design environment.  It never used to do this in VB6, as when you ran the application, the group of radio buttons would have no members selected.

The problem manifests itself when you are trying to perform additional tasks in the CheckedChanged event of the radio buttons when the user selects one of the radio buttons, since the first radio button is being automatically selected.

I asked this question on Stack Overflow, and got a couple of replies. The one that I finally used to solve the problem was to set the Checked property of the radio buttons to false in the form’s Shown event, which I had never used before. By doing this, the first radio button was no longer automatically showing up checked.

One other thing that I had to do in addition was to cast the sender into a RadioButton and look at the Checked property of the clicked radio button in the CheckedChanged event, as that event is fired for radio buttons both being turned on and also turned off.

Oh, and happy National English Toffee Day!