Gio's Blog

April 28, 2011 a Microsoft Community Contributor Award!

2011-04-27T19:06:00.000-07:00

I am proud and happy that today I got an email from Microsoft saying that "I was being recognized with Microsoft Community Contributor Award!"

This award earned me access to more resources from Microsoft. And will empower more to people like me who like to share and contribute to the community. Sharing and contributing to WPF and ADO.NET Entity forum is also a great opportunity to learn.

This is a great encouragement to me to continue what has been started.
and I am proud to say that this is my first badge on this small blog. :-)

Thanks Microsoft for giving me this Microsoft Community Contributor Award.

I accepted it with both hands.

How to make your xlmns pointing to URL

2011-04-24T00:46:00.000-07:00

Quite a few WPF developer knows that we can customize on how XAML namespaces represents the actual assembly (.dll). I too sometimes forgot how to customize it that is why I blogged this out.

When we represent the assembly/namespaces (dll) in our XAML; we do specify like this

   
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

When we have our own namespace or assembly of controls we declare something like the bottom so that we could use some controls.

xmlns:custom="clr-namespace:WpfCustomControlLibrary1;assembly=WpfCustomControlLibrary1"

Actually, we also do namespacing like that one on the top which represent the presentationcore.dll To do it, we can put XMLDefinition in our namespaces.

[assembly: XmlnsDefinition("http://www.gioVhan.com", "WpfCustomControlLibrary1")]
namespace WpfCustomControlLibrary1
{
  .....
}

In this way, the "http://www.gioVhan.com" is the representation of our assembly thus we can type like.

This is a very cool feature in WPF. When designing your own assemblies, you can create something like this. It will represent a more and clear namespace rather than pointing to clr-...

I will check on VS2010/EF4.0 if this feature was changed.

Thanks.

Does your Project Manager have these criteria?

2011-03-23T20:27:00.000-07:00

I've been in the IT industry for a quite sometime and always working with passion.
I've been a Project Manager (sort of) since, I manage and handle almost all task in the Software Development Life Cycle. From initial stage downto deployment and maintenance.
From requirement gathering to development and testing. I am very hands-on in terms of both Analysis and coding.

I am proud to say I have masteral units in Business Management (missing 6units :-) ) thus allows me to handle bad and good situations, decisions and planning. MBM has a lot inside, to handle pressure, production, finance matters, people, etc.

I am an observant type; I observed how people do react in a certain situation;
I came to write track how far does your PM goes. Or as the title itself.
Here are Top 10 Qualities of PM (from a good article)
1. Inspired a Shared Vision
2. Good Communicator
3. Integrity
4. Enthusiasm
5. Empathy
6. Competence
7. Ability to Delegate Task
8. Cool under pressure
9. Team Building Skills
10. Problem Solving Skills.

You can add as many as you can. You can also debate what is inside it.
To be a good project manager you must also have like (wiki)

http://en.wikipedia.org/wiki/Project_management

Good PM doesnt always mean that you have a successful product delivery.
It is how you plan, handle resources (both hardware and peopleware), react and handle to situations in different aspects.

Article Link:
http://www.projectsmart.co.uk/top-10-qualities-project-manager.html

Question a Threading

2011-03-21T23:43:00.001-07:00

I cannot believe somebody ask the expected result regarding threading.
I came across to find out and prove if he is correct.

The code snippet :


   class Program
    {
        static void Main(string[] args)
        {
            Thread s1 = new Thread(Display1);
            Thread s2 = new Thread(Display2);

            s1.Start();
            s2.Start();
            for (var i = 0; i <= 10; i++)
            {
                Console.WriteLine(string.Format("Main 1 : {0}", i.ToString()));
            }

            Console.ReadKey();
        }

        static void Display1()
        {
            for (var i = 0; i <= 10; i++)
            {
                Console.WriteLine(string.Format("Display 1 : {0}", i.ToString()));
            }
        }

                static void Display2()
        {
            for (var i = 0; i <= 10; i++)
            {
                Console.WriteLine(string.Format("Display 2 : {0}", i.ToString()));
            }
        }
    }

According to the questionaire, the correct answer would be
1. Display 1: 0 to Display 1: 10
2. Main 1: 0 to Main 1: 10
3. Display 2: 0 to Display 2: 10

As I execute the code, it seems to negate the statement. It would display, different display everytime I will execute. This is because, there is a timing or a specific period of time where a thread will start. But most of the time, it should go as expected.

some output :

If anybody wants to understand and have a good start regarding THREADING.
you can start from here.

http://msdn.microsoft.com/en-us/library/aa645740(v=vs.71).aspx

WPF Animation when Databing source is updated.

2009-12-05T06:30:00.001-08:00

I find a little time to blog this very nice feature on WPF.
More and more people seems to play with WPF animation.

Sometimes in a multi-user environment, updated data is very
important aspect in computing. Users wants to see what other
people are doing with other data by just their own client machine.

With a Mixture of RTI or any messenging over an infrastructure,
and with CEP concepts, data can be PUSH and PULL over the wire.

To play along for the user if their console will be updated
with the new data, We will use just XAML code to detect if
there are changes with our BindingSource.

Here it is as simple.

Using an EventTrigger with RoutedEvent="Binding.TargetUpdated"
allows the WPF to detect if your datasource has been updated.
If this is true, then the storyboard executes. It changes the specific
textbox (if you set this one on your textbox style) color from blue to transparent.
Remember to set your this Trigger in your style.

Have fun.

Sometimes simple information helps.

WPF Exception

2009-12-02T07:28:00.000-08:00

Wow, it's been a while I haven't updated this blog.

Some people are looking for direct answer and some people
doesn't care at all but needs an answer.

Today, I'll make straight points discussing WPF Exceptions.
The list below are the basic way to catch or look an exception.

1. Try..Catch..Finally block.

2. Using the Application.DispatcherUnhandledException

3. looking at Silent exceptions.

1. Try..Catch..Finaly block still the most commonly used to catch almost all types of errors during run-time.
this statement is very easy to use... for example


            string a = null;
            try
            {
                if (a == null) throw new NullReferenceException();
            }
            catch (NullReferenceException e)
            {
                //exception 1
            }
            catch (FieldAccessException fex)
            {
                //exception 2.......
            }
            finally
            {
                //finally block executed with or without error....
            }

NOTE : If you are concerned about performance, I don't suggest that you use "try.. catch.." block.. this will swallow the exception and can possibly don't throw your exception to your UI level.

In this section I will not discuss handling this kind of exception in Multi-threading.

2. Using the application level to catch exception thrown by any of your code is the most simple and yet effective type of catching error. To do this in WPF, you write your code in the Application.Xaml code behind. On Application.xaml.vb (cs), type your custom handler on the Application_DispatcherUnhandledException() method. This can catch your exception. voila...
You can now have your exception handler without worrying other developers cathing
exception.

3. The last exception that I will be pointing out are those silent exceptions, silent exceptions
mostly don't interact with your UI thread level. If you are running your application inside
your Visual Studio, you can actually locate them at the Output Window. Most of these exceptions
are caused sometimes by WPF databinding. Using MVVM actually cannot detect binding errors
at design time so be careful.
Silent Exceptions also has performance penalty if you don't handle them. So, you better
check and clear these kind of exceptions in your apps.

Make it simple. The key to handle these exceptions.

Enjoy. GTG. Thinking other things for my ASP.NET project.

WPF Image Zoom when MouseFocus

2009-07-07T17:39:00.000-07:00

I actually spent a day trying to figure out how to apply render transform to all images in a style. It is pretty simple using XAML and this without using any-code behind.
Then ScaleTransform ScaleX and ScaleY was binded to the ActualWidth and ActualHeight of the Image and make use of the “DoubleSplitConverter” to divide the width and height to enable the image transform on the center of its location. As what MSDN (http://msdn.microsoft.com/en-us/library/system.windows.media.scaletransform.aspx).

XAML Code:


         <Style TargetType="{x:Type Image}" >
                <Setter Property="Margin" Value="4"/>
                <Setter Property="RenderTransform" >
                    <Setter.Value>
                        <ScaleTransform ScaleX="1" ScaleY="1" CenterX="{Binding RelativeSource={RelativeSource AncestorType={x:Type Image}, AncestorLevel=1}, Path=ActualWidth, Converter={StaticResource DoubleSplitConverter}}" CenterY="{Binding RelativeSource={RelativeSource AncestorType={x:Type Image}, AncestorLevel=1}, Path=ActualHeight, Converter={StaticResource DoubleSplitConverter}}" />
                    </Setter.Value>>
                </Setter>
                <Style.Triggers>
                    <EventTrigger RoutedEvent="Image.MouseEnter" >
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Image.RenderTransform).(ScaleTransform.ScaleX)" To="1.5" Duration="0:0:0.20" />
                                <DoubleAnimation Storyboard.TargetProperty="(Image.RenderTransform).(ScaleTransform.ScaleY)" To="1.5" Duration="0:0:0.20" />

                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                    <EventTrigger RoutedEvent="Image.MouseLeave" >
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Image.RenderTransform).(ScaleTransform.ScaleX)" To="1" Duration="0:0:0.20" />
                                <DoubleAnimation Storyboard.TargetProperty="(Image.RenderTransform).(ScaleTransform.ScaleY)" To="1" Duration="0:0:0.20" />

                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                </Style.Triggers>
            </Style>

Then, we do have “DoubleAnimation” on RoutedEvent “Image.MouseEnter” which enables the scaleX and ScaleY to be adjusted to 1.5. “MouseLeave” does it so to return to its size 1.
The Storyboard.TargetProperty signifies that we apply these animation to the {Image.RenderTransform}.{ScaleTransform.ScaleX and Y}. This statement will not work if we don’t have a value for our RenderTransform property of <ScaleTransform>
This is the Converter to use just dividing it by 2.


    Public Class DoubleSplitConverter
        Implements IValueConverter


        Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert
            Dim mValue As Double = value
            Return mValue / 2
        End Function

        Public Function ConvertBack(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack
            Dim mValue As Double = value
            Return mValue * 2
        End Function
    End Class

Hope you like it.

Oil on Canvass and Butterfly wings

2009-06-10T21:42:00.000-07:00

I'll post another great art by my sister. This is I think Oil in canvass.
I know for a fact that she can paint in a charcoal but this is something
she loved to do.

Although I am not an artist since by default I am Software Developer,
but I appreciate this kind of mastery.

A. Fisherman dragging his boat to shore.

B. Horsey

C. Herself on Sinulog outfit.

Do you believe the following are butterfly wings that are joined
together to create a stunning image.

D. Froggy

D. Birdy.

These are only sample of their great skills.
I will try to program this in WPF and see if works.

Family of Artist - miniatures and lifesize

2009-05-13T21:44:00.000-07:00

I got to stop thinking WPF and .Net for a while; and share this
very amazing craftman's work. All images you will see below
are made of cartoon or cardboard. It's amazing how this guy
created a masterpiece.

A. Would you believe this is a lampshade? It's about 20 inches tall 13in wide.
You will see more images

Can you Imagine the details of this work? how small and precise? IT's amazing.

Another image i would like to show is a lifesize gun or armalite? anyway here it is.

There are other miniatures like boat of 18th century, offices, building, Jet Fighter F16, etc.

All I can say is a big wow to his talent.
Oh, by the way, the flower portrait (oil in canvas) is from his wife.

Make the world know you!!!!!

Limiting WPF Textbox Input character

2009-01-27T23:54:00.000-08:00

Today, I spend almost 2 hours looking for answers.
I look like stupid on how to control or validate the accepted characters that the textbox
would accept. A very simple problem in the good old days.

i got some answers from

http://www.vbdotnetforums.com/windows-presentation-foundation-wpf/23881-ascii-value-instead-system-windows-input-key.html

I appreciate the solution above, but some has to validate what kind of characters are
accepted.

but hey, it's much as easy as it would be, the PreviewTextInput() event is the right answer;
giving the correct character pressed on the keyboard and is not returning the
Windows.Input.Key types...

Here is the sample.

Private Sub Textbox_PreviewTextInput(ByVal sender As Object, ByVal e As System.Windows.Input.TextCompositionEventArgs) Handles Me.PreviewTextInput
If e.Text = "a" ' will not accept "a"
e.Handled = True
Else
e.Handled = False
End If
End Sub

Sorry for the HTML format..
Enjoy.

Transporting Large Ado.Net Entity in WCF Error

2008-12-10T18:20:00.000-08:00

This could be a reference other post who encounter the same problem as mine.
I have a simple WCF Server/Client Scenario; with Operation Contract
that returns ado.net entity (Objects.DataClasses.EntityObject)

Public Class GenericService
Implements IGenericService

Public Function RetrieveData() As Object Implements
Dim _Context As New CustomerEntities
Dim myData = From OneRecord In _Context.Customers Select OneRecord Where OneRecord.CustomerId = "AAA"
Return myData
End Function

End Class

However, in the return process.. I got this Error

The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:01:00'.

Some other posting has same error but different solution

- by Denis Pitcher --> http://geekswithblogs.net/Denis/archive/2008/10/07/125688.aspx

- Other forum --> http://www.themssforum.com/Framework/Error-139943/

In my part, it seems large amount of message was passed through the channel.?

Hope anyone seeing this.

WPF BitMapImage Converters and SQL Image

2008-11-23T16:42:00.000-08:00

Learning in progress.

For obvious reasons, there are developers needs to save the images
whether .jpg or .png to backend, specifically to MS SQL image type.

WPF can handle both retrieving and saving of Images through converters.

TO DISPLAY
Let us assume that you use DataTemplate to display your image as part
of our listview columns.

-- on window resources / or app resources
declare the template for the image and this will be part of listview's column


<DataTemplate key="TemplatePic">
<Image Name="myImage" Source="{Binding Path=EmployeePic, Converter="{StaticResource ByteToImageConverter}} />
</DataTemplate>

-- on ListView, define the template for the gridview column


<Listview name="ListView1">
<ListView.view>
<GridView>
<GridViewColumn header="Image" name="myPicture" celltemplate="{StaticResource TemplatePic}">
<GridView>
</ListView.View>

--for your converter resource class 

Public Class ByteToImageConverter
Implements IValueConverter


Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert
If value Is Nothing Then
Return Nothing
End If
Dim picByte As Byte() = value
Dim bi As BitmapImage = New BitmapImage()
bi.BeginInit()
Dim ImageStream As IO.Stream = New IO.MemoryStream(picByte)
bi.StreamSource = ImageStream
bi.EndInit()
Return bi 
End Function


Public Function ConvertBack(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack

>
    Dim rtb = New RenderTargetBitmap(value.Width, value.Width, 92, 92, PixelFormats.Pbgra32)
    rtb.Render(value)
    Dim enc = New System.Windows.Media.Imaging.PngBitmapEncoder()
    enc.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(rtb))
    ' array of byte for the image
    Dim mPicBtye As Byte() = Nothing
    Using mMemStream As IO.MemoryStream = New IO.MemoryStream
    enc.Save(mMemStream)
    mPicBtye = mMemStream.ToArray
    End Using
Return mPicBtye

End Function
End Class

In the Convert() function converts the "value" from byte() to a BitMapImage using IO.Stream. This reads the value saved from the backend and convert it to the memory stream of byte.

The ConvertBack() function is a reverse process wherein we have converted the BitMapImage back to Byte().

The example above is very traditional but uses memory stream to convert the image.

Hope you like it.

Disney and WPF Step by step ComboBox Binding to observablecollection

2008-08-03T17:07:00.000-07:00

California - a very nice place to live.

Roaming around San Franciso is something that could be cherished. Watching and taking pictures on Pier 39, Downtown and the Golden Gate is so cool. Disney and Hollywood is a big WOW. One thing I like is that the people are so courteous and always smiling, greeting everybody around. Definitely a very nice place to live.

Let's discuss WPF's combo box binding. Once you learn it, it is very convenient to use.

There are a lot of sources and great blogs on how to use them.
Julie Lerma Blog and Microsoft's binding queen Beatriz Costa are one examples.

For here : I will just concentrate on binding ComboBox

For me, there are 2 important things to remember about comboboxes.
1. Where to retrieve data as combobox sources.
2. Where to save data of the SelectedValue or the Text displayed on the box.

ComboBox ItemSource

WPF Suggested to bind UIElement to an ObservableCollection to achieve high performance. I will not discuss binding to LINQ Entities here for LINQ entity results will have an enumerable / list. Let us create our own observable collection class.

Assume that we have a Places.vb

-------------
Imports System.Collections.ObjectModel

Namespace PlaceDataSource
Public Class Places
Inherits ObservableCollection(Of String)

Public Sub New()
MyBase.Add("California")
MyBase.Add("New York")
End Sub
End Class
End Namespace
---------------

Now, inorder for you to use that class as your itemsource for the combobox, we need the following.

Set the Namespace in the window namespace reference.
Set the Resource of the window or page.
Set combobox itemsource property to point to static resource declared by XAML.

1. Set the Namespace in the window namespace reference.
Declaration of resources can be declared in either window level or by application level. Let us use the window level to make it simple. Thus, on window xmls area we declare the namespace.
xmlns:places="clr-namespace:WpfApplication4.PlaceDataSource"
Note : That VS2008 designer will display all clr-namespaces as you type "xmlns:", then just select the PlaceDataSource Namespace.
2. Set the Resource of the window or page. - Right after referencing the namespace, we can set the resource of the window to.
<Window.Resources>
<places:Places x:key="PlaceBound" />
</Window.Resources>

3. Set combobox itemsource property to point to static resource declared by XAML. In setting the combobox itemsource, just drag your combobox in the window/page. then put the data source like below.

<ComboBox ItemsSource="{StaticResource PlacesBound}" />

and then... Run the program.. tsada... there you go... ComboBox will have its displaymember from our observablecollection....

As I've said, there are several ways to set combo's itemsource. You can bind it from XML, Enum, Enumerable.