Silverlight as a mechanism for simplification of application deployment

Cannot uninstall Silverlight 4 and you want to install Silverlight 5

I faced this problem recently. I tried and tried but I got different error messages for uninstall Silverlight 4 SDK and I needed to upgrade to Silverlight 5.

So after a lot of tears and suffering I came across the Microsoft Fix it.

http://support.microsoft.com/mats/Program_Install_and_Uninstall

I runned this program and indicated that I wanted to uninstall Microsoft Silverlight 4 SDK and it was like magic!

It checked the registry, and fixed it, and then uninstalled the MS Silvelight 4 SDK.

After that I just download the new installer run it and everything work! Isn’t it something J

Printing BarCodes in Silverlight

Well I tought this was gonna be more difficult, but no. The Silverlight community is great and there are tons of
of  code out there.

So I found a great project in codeplex called obviously http://silverlightbarcode.codeplex.com/

And printing barcode with that library is a peace of cake.

Just do something like this:

private void button1_Click(object sender, RoutedEventArgs e)
{
    var p = new PrintDocument();
    p.PrintPage += new EventHandler<PrintPageEventArgs>(p_PrintPage);
    p.Print("NuevoDocument");
}

void p_PrintPage(object sender, PrintPageEventArgs e)
{
    Canvas canvasBarCode = new Canvas();
    canvasBarCode.Width = 200;
    canvasBarCode.Height = 200;
    Me.BarcodeSoftware.Barcode.Barcodes barcode = 
           new Me.BarcodeSoftware.Barcode.Barcodes();
    barcode.BarcodeType =        
                  Me.BarcodeSoftware.Barcode.Barcodes.BarcodeEnum.Code39;
    barcode.Data = "123456";
    barcode.encode();
    string encodedData = barcode.EncodedData;
    //if you want to put the barcode number 
        // add a label to canvas and set text to barcode.HumanText;

    int encodedLength = 0;
    for (int x = 0; x < encodedData.Length; x++)
    {
        if (encodedData[x] == 't')
            encodedLength++;
        else if (encodedData[x] == 'w')
            encodedLength = encodedLength + 3;
    }

    float barWidth = (float)(canvasBarCode.Width / encodedLength);

    if (barWidth < 1) barWidth = 1;
    float thickWidth = barWidth * 3;
    double incrementWidth = 0;

    int swing = 0;
    for (int x = 0; x < encodedData.Length; x++)
    {
        Brush brush;
        if (swing == 0)
            brush = new SolidColorBrush(Colors.Black);
        else
            brush = new SolidColorBrush(Colors.White);

        if (encodedData[x] == 't')
        {
            Rectangle r = new Rectangle();
            r.Fill = brush;
            r.Width = barWidth;
            r.Height = canvasBarCode.Height;
            r.SetValue(Canvas.LeftProperty, incrementWidth);
            r.SetValue(Canvas.TopProperty, 0.0);
            canvasBarCode.Children.Add(r);
            incrementWidth = incrementWidth + ((barWidth));
        }
        else if (encodedData[x] == 'w')
        {
            Rectangle r = new Rectangle();
            r.Fill = brush;
            r.Width = 3 * barWidth;
            r.Height = canvasBarCode.Height;
            r.SetValue(Canvas.LeftProperty, incrementWidth);
            r.SetValue(Canvas.TopProperty, 0.0);
            canvasBarCode.Children.Add(r);
            incrementWidth = incrementWidth + (3 * (barWidth));
        }

        if (swing == 0)
           swing = 1;
        else
           swing = 0;
    }
    e.PageVisual = canvasBarCode;
    e.HasMorePages = false;

}

Printing BarCodes in Silverlight

Well I tought this was gonna be more difficult, but no. The Silverlight community is great and there are tons of
of  code out there.

So I found a great project in codeplex called obviously http://silverlightbarcode.codeplex.com/

And printing barcode with that library is a peace of cake.

Just do something like this:

private void button1_Click(object sender, RoutedEventArgs e)
{
    var p = new PrintDocument();
    p.PrintPage += new EventHandler<PrintPageEventArgs>(p_PrintPage);
    p.Print("NuevoDocument");
}

void p_PrintPage(object sender, PrintPageEventArgs e)
{
    Canvas canvasBarCode = new Canvas();
    canvasBarCode.Width = 200;
    canvasBarCode.Height = 200;
    Me.BarcodeSoftware.Barcode.Barcodes barcode = 
           new Me.BarcodeSoftware.Barcode.Barcodes();
    barcode.BarcodeType =        
                  Me.BarcodeSoftware.Barcode.Barcodes.BarcodeEnum.Code39;
    barcode.Data = "123456";
    barcode.encode();
    string encodedData = barcode.EncodedData;
    //if you want to put the barcode number 
        // add a label to canvas and set text to barcode.HumanText;

    int encodedLength = 0;
    for (int x = 0; x < encodedData.Length; x++)
    {
        if (encodedData[x] == 't')
            encodedLength++;
        else if (encodedData[x] == 'w')
            encodedLength = encodedLength + 3;
    }

    float barWidth = (float)(canvasBarCode.Width / encodedLength);

    if (barWidth < 1) barWidth = 1;
    float thickWidth = barWidth * 3;
    double incrementWidth = 0;

    int swing = 0;
    for (int x = 0; x < encodedData.Length; x++)
    {
        Brush brush;
        if (swing == 0)
            brush = new SolidColorBrush(Colors.Black);
        else
            brush = new SolidColorBrush(Colors.White);

        if (encodedData[x] == 't')
        {
            Rectangle r = new Rectangle();
            r.Fill = brush;
            r.Width = barWidth;
            r.Height = canvasBarCode.Height;
            r.SetValue(Canvas.LeftProperty, incrementWidth);
            r.SetValue(Canvas.TopProperty, 0.0);
            canvasBarCode.Children.Add(r);
            incrementWidth = incrementWidth + ((barWidth));
        }
        else if (encodedData[x] == 'w')
        {
            Rectangle r = new Rectangle();
            r.Fill = brush;
            r.Width = 3 * barWidth;
            r.Height = canvasBarCode.Height;
            r.SetValue(Canvas.LeftProperty, incrementWidth);
            r.SetValue(Canvas.TopProperty, 0.0);
            canvasBarCode.Children.Add(r);
            incrementWidth = incrementWidth + (3 * (barWidth));
        }

        if (swing == 0)
           swing = 1;
        else
           swing = 0;
    }
    e.PageVisual = canvasBarCode;
    e.HasMorePages = false;

}

Silverlight ObservableCollection with AddRange

Silverlight is when you have to add a lot of items.
I know, I know maybe you should choose another way to show that data,
but leaving philosophical-ui design discussions, the real problem is that
usually those components are bind  to ObservableCollections.

ObservableCollections are a bit of an exhibitionist.
Each time you add an item it will yell

Hey!! Yoo-hoo! HEY!!! YOU!!
I'm HEREEEEEEEEEEEEEEEEEE!!!!
Look at me!! Look at Me!!! Look Mom No Hands!!! Look Dad no Feet!!! HEY!!!!!!!!

So if you have some code like:

for(int i=0;i<10000;i++)
{
    comboItems.Add("item" + i);
}

A nice thing will be to be able to do something like:

var items = new String[10000] 
for(int i=0;i<10000;i++) 
{ 
    items[i]="item" + i; 
} 
comboItems.AddRange(items); 

And then provide just ONE notification of Collection Changed instead of a lot of
little cries for attention.

Well that is the reason for this new version of ObservableCollection that I call
RangeObservableCollection:

using System;
using System.Collections.ObjectModel;
using System.Collections.Generic;

namespace Utils
{
    public class RangeObservableCollection<T> : ObservableCollection<T>
    {
        private bool _suppressNotification = false;

        public RangeObservableCollection() : base() { }

        public RangeObservableCollection(IEnumerable<T> collection) : base(collection) { }

        protected override void OnPropertyChanged(System.ComponentModel.PropertyChangedEventArgs e)
        {
            if (!_suppressNotification) base.OnPropertyChanged(e);
        }

        protected override void OnCollectionChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            if (!_suppressNotification)
                base.OnCollectionChanged(e);
        }

        /// <summary>
        /// Adds a collection suppressing notification per item and just raising a notification
        /// for the whole collection
        /// </summary>
        /// <param name="list"></param>
        public void AddRange(IEnumerable<T> list)
        {
            if (list == null) throw new ArgumentNullException("list");
            _suppressNotification = true;
            foreach (T item in list)
            {
                Add(item);
            }
            _suppressNotification = false;
            OnCollectionChanged(new System.Collections.Specialized.NotifyCollectionChangedEventArgs(System.Collections.Specialized.NotifyCollectionChangedAction.Reset));
        }

    }
    
}

Profiling Silverlight Applications with Visual Studio 2010

The VS Profiler Team has an excellent post teaching how to use the VS2010 profiler with Silverlight Applications.

The steps are simple.

Run the A Visual Studio Command Prompt

And follow these steps:

1. VSPerfClrEnv /sampleon
2. "c:\Program Files (x86)\Internet Explorer\iexplore.exe" C:\Breakout\Breakout\Bin\Release\TestPage.html
3. VSPerfCmd /start:sample /output:MyFile /attach:<PID of iexplore.exe process>
4. Run your scenario
5. VSPerfCmd /detach
6. VSPerfCmd /shutdown
7. VSPerfClrEnv /off

NOTE: information reposted from http://blogs.msdn.com/b/profiler/archive/2010/04/26/vs2010-silverlight-4-profiling.aspx

When the finish you will have a file called MyFile.vsp and just open that with VS2010.