Ash Tewari – Page 13

Dial Gauge is a ProgressBar

I am not just being philosophical here. In WPF, ControlTemplates allow you to transform a control’s appearance. This is not the same as applying stylesheets. This is an entirely new level of customization. What you see in the screenshot below looks like a Dial but is actually a simple ProgressBar control wearing a “Dial” template. The Dial template was created using Microsoft Expression Blend .

Include the ControlTemplate as a Window.Resource and then assign it to ProgressBar element’s Template attribute :

Of course that is not all. The ControlTemplate must define some named elements of FrameworkElement type. Charles Petzold has explained it in detail : MSDN Magazine Article. So, I will not repeat it here.

The sample code can be downloaded here : DialTest.zip
License : Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

PostSharp with SharpDevelop

SharpDevelop3.0 uses MSBuild. Including PostSharp in your build process is transparent if you are doing a global install using PostSharp installer. If you are doing a per-project installation using “Binary – No Installer” download, you will need to import the PostSharp targets into your .csproj file –


    True

C:\code\PostSharp-1.0.8.316-Binary\

For more details, read the install instructions included in the PostSharp download and under-the-hood-of-msbuild-integration.

To use local PostSharp binaries (relative to your project) , modify your .csproj file as follows –

  
    True
    $(MSBuildProjectDirectory)\PostSharp\

$(MSBuildProjectDirectory) is the directory containing your .csproj file.
\PostSharp\ is the directory containing local PostSharp binaries.

2. You will need to exclude the Aspect class itself from being woven.

If you are following the getting-started sample, see the following example:

[Serializable]
[Trace( null, AttributeExclude = true )]
public sealed class TraceAttribute : OnMethodBoundaryAspect
{

3. Compile your project.

Using Custom Converter in XAML

In my previous post : WPF-LINQ To SQL Sample, I had to resort to modifying .dbml file to get the images stored as varbinary into the WPF ListView control. I had to change the Type of image fields to System.Byte[], instead of using System.Data.Linq.Binary. A better way to do this is to use a custom converter. WPF allows you to specify custom converter as part of the Binding in .xaml, like this –

<Image Grid.Row="2"
Source="{Binding Path=ThumbNailPhoto ,
Converter={StaticResource imageConverter}}"></Image>

The custom converter is declared in the same .xaml file as a resource –

<Window.Resources>
<local:ImageDataConverter x:Key="imageConverter" />
</Window.Resources>

ImageDataConverter is implemented in .xaml.cs file –

public class ImageDataConverter : IValueConverter
{
   public object Convert(object value, Type targetType, object parameter,
   System.Globalization.CultureInfo culture)
   {
      byte[] image = ((System.Data.Linq.Binary)value).ToArray();
      return image;
   }

   public object ConvertBack(object value, Type targetType, object parameter,
   System.Globalization.CultureInfo culture)
   {
      throw new NotSupportedException();
   }
}

The updated sample code can be downloaded here : WPF-LINQ to SQL Sample
License : Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

WPF – LINQ to SQL Sample

This exercise in binding a WPF ListView control with LINQ to SQL was a lot of fun ! The following image shows data from AdventureWorks sample database displayed in the ListView control. The end result is very admirable, even in this very basic demo. Feeling a complete sense of freedom is unavoidable when working with WPF.

This sample demonstrates :

LINQ to SQL mapping.
WPF ListView Control DataBinding.
Displaying images stored in database as varbinary in WPF control.

The sample code can be downloaded here : WPF-LINQ to SQL Sample
License : Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

Customize log4net Output Path

The default log4net output path is relative to the startup directory of your executable. To customize the output path, you can override the base Appender’s File property in your own Appender class. The following example describes how to route the log files relative to the temp folder :

   public class MyOwnAppender : log4net.Appender.RollingFileAppender
   {
         public override string File
         {
             get
             {
                 return base.File;
             }

            set
            {
                if (Path.IsPathRooted(value))
                {
                    base.File = value;
                }
                else
                {
                    base.File = Path.Combine(Path.GetTempPath(), value);
                }
            }
        }
    }

Your log4net config file must be modified so that log4net can locate and use your custom Appender. If MyOwnAppender is in MyNamespace and you have implemented it in MyLoggerLib.dll :

Career Advice

The value of any advice is tied to the degree of its relevance to your particular situation and circumstances. Very specific advice, like legal and medical advice, is very expensive. It is very relevant to the individual’s situation and therefore quite valuable. The degree of relevance of inexpensive/free advice to your specific circumstances is usually very low. Inexpensive/free advice, as in sayings and quotes, but also in everyday personal and business communication, is very generic. The same message is usually perceived differently by different people. Especially when the entire message is very succinct and pithy. Various aspects of the message are accentuated differently as it is filtered through individual perception.

Developing a sense of how generic advice applies to your individual situation is invaluable.
Experience, observation and reading feeds the awareness.
Trying and learning from mistakes is essential.
Applying the lessons completes the circle.

One of the best career advice I ever got was from reading Spencer Johnson’s Who Moved My Cheese ? The message in this book is timeless. I had been through many significant changes in my life and I think I have handled those changes quite well. After reading this book in 2001, I became consciously aware of the existence of change and my own patterns of behavior and responses to events of change. This awareness has helped me anticipate change, prepare better, make better decisions and handle change more productively.