Popups in wpf

Here is come code to show a popup in wpf, i've nothing in the popup at the moment, just a gradient background and border.


<Popup Name="popup1" 
   Width="{Binding ElementName=bdrCalendar, Path=ActualWidth, Converter={StaticResource MarginValueConverter}}"
   PlacementTarget="{Binding ElementName=bdrCalendar}"
   MouseDown="popup1_MouseDown" >
 <ctrls:PopupContent />






RIA Services

Over the w/end I was helping a mate with his Data-driven Silverlight app.

I was gobsmacked that his developer spent days and weeks writing plumbing code, hand coding infrastructure code and even worse my friend had to pay for it.
Being able to focus on the business needs is important so having a development platform that better enables that focus and increased productivity is an absolute must.

The solution to this problem is codenamed Alexandria i.e. .NET RIA Services, this technology provides a set of server components and ASP.NET extensions that ease the n-tier development process, making your applications almost as easy to develop as if they were running on a single tier, In addition, services such as authentication, roles and profile management are provided. The combination of client and server enhancements to Silverlight 3 and ASP.NET along with the addition of .NET RIA Services, streamline the end-to-end experience of developing data-driven Web applications also known as Rich Internet Applications, or RIAs.

I’m not going to show you how to do it as there are many-many training resources available but a good place to start is here: http://silverlight.net/getstarted/riaservices/

So if you find yourself writing needless plumbing code for a DAL in Silverlight, then spend some time figuring RIA services out!
(Spend some get some diesel for that digger and opposed to grabbing a shovel and diving in!!)



Filtering data in Silverlight

Ever want to filter data in Silverlight? here's a simple example that uses a lambda expression to search on name (case sensitive)



ComboBox cbx = ((ComboBox)sender);

ICollectionView dataView =
if (!string.IsNullOrEmpty(cbx.Text))
    dataView.Filter = f => ((Job)f).Name.Contains(cbx.Text);
    dataView.Filter = null;


Cocoa Is My Girlfriend

Tonight I've stumbled across an interesting Blog on cimgf.


It's been many years since I wrote PHP, so I'd naturally use asp.net serverside (or if i had a pc powerfull enough I'd use the new REST capabilities of Sharepoint 2010 server).

I've been dying to have a play with Azures for sometime now but I'm always either snowed under with work or playing with some other technology, I remember reading that Azures (storage at least) has a REST API, and with the launch of the iPhone on the Vodafone network at the end of this month I've been looking into what's involved in writing objective C (and some mono stuff) so it seems I may finally get to have a play :-)


Silverlight 4 Databinding and VS2010

If you've got a data driven application, databinding is the infrastructure of choice that makes the link between data and your UX

Silverlight 4 has a few improvments that brings it closer to WPF

  • TargetNullValue  - lets you specify the what to display in the target when the source value is null
    e.g.  {Binding Path=Name, TargetNullValue=NoName}
  • StringFormat - specify how a strnig should be formatted
    e.g.  {Binding Path=Salary, StringFormat=C}
  • FallbackValue - I love this one, comes in pretty handy when dealing with polymorphic classes where a you know in advance what properties specialized classes have and want to display them... or display a fallback value if they don't exist.
    e.g.  {Binding Path=LastLoggedOn, FallbackValue=Never}



Silverlight and WPF


Tonight I tried to use the FlowDocument that you'll know well if you are familiar with WPF....

Important part above "tried to use"  .... but  ... silverlight version 3 doesn't support it :-(

Thats a second thing I've found lacking as I move some code to Silverlight, i've also found that DataTriggers don't work like the do in WPF Cry

Different views in WPF/Silverlight

In my early WPF days I noticed the magic that having two different controls bound to the Same ObservableCollection meant that when I selected an item in one control, the same item got selected in the other.... which i I didn't want.

CollectionViewSource To the rescue

<local:MyData x:Key="MyData"/>  
    <CollectionViewSource x:Key="AllData" Source="{StaticResource MyData}"/>  
    <CollectionViewSource x:Key="SearchData" Source="{StaticResource MyData}" Filter="MySearch"/>  
<ListBox ItemsSource="{Binding Source={StaticResource AllData}}"/>  
<ListBox ItemsSource="{Binding Source={StaticResource SearchData}}"/>



C# 4.0 Dynamic Keyword

"object x" is a shorthand for "System.Object x".
This declares the variable x to have the type System.Object, this is strongly typed.
And since C# provides autoboxing, you can assign anything you want to this variable.

"var x = E" declares a variable x to be of the type of the expression E.
The E is required, not optional. This is a strongly typed declaration, and you can only assign values whose type is typeof(E) to it.

"dynamic x" declares the variable x to have dynamic semantics.
This means that the C# compiler will generate code that will allow dynamic invocations on x.
The actual meaning of "x.M" is deferred until runtime and will depend on the semantics of the IDynamicObject implementation

C# on the iPhone

Recently I've noticed that the country has gone iPhone mad and I'm starting to buy into it myself... my blackberry days may be numbered as the only distinct advantage I see is that bandwidth is not used retrieving emails... but nowadays bandwidth is not so much as issue,, e.g. you get 2gb a month on a vodafone contract Cool

I've had a bit of a play around with Objective-C, interesting but .NET is my forte so I was delighted to see that it was possible (kinda0 to write code in c# for the iPhone platform.

The success of .NET platform from MS on multiple systems came when the Mono project became real. This open-source framework (cross-platform) brought the speed of C# development to Linux and OSX platforms. And now it will take us further.

As we all know, Apple has a highly strict inclusion policy for third-party runtime environments, which makes impossible to distribute apps that use this technology, like .NET and Java. So how can I be talking about .NET on the iPhone?

Because of a process called Static Compilation. Mono had already created a way to generate native code from common intermediate language (CIL) produced by .NET in native code in the past (AOT Ahead-OfTime compilation), with the intention of helping to reduce the speed of the initialization process and increase the process sharing among multiple processes. However, to keep the portability among different machines, a small piece of code was still in JIT (just-in-time) compilation – this method is the key to virtual machine systems that generate intermediate code which is converted to native code during execution.

So this process generates the final result in native code BEFORE the executing time, and this decreases also the size of the final app (since framework must go with the app), which does not need to load the codes to execute JIT and interpret CIL – even though it still adds approximately 6Mb from mono framework itself in the app’s final size.

There are also a few other tricks and Mono features that developers can use to reduce the size of Mono executables and assemblies for deployment in mobile environments. You can use the Mono linker to shrink the library size, you can omit the JIT and code generation engines from the executables, and you can strip out CIL instructions from the assemblies.

Static compilation makes it possible to build Apple-approved iPhone applications with Mono, but it comes with some limitations. Generics and dynamically-generated code are currently not supported when AOT compilation is used.

There are a lot of hoops to jump through right now to set up iPhone cross-compilation for Mono, but de Icaza (Novell's lead mono developer) says that developers who want to start now can use Unity, a third-party commercial programming framework for 3D game development that is built on Mono. Unity supports several platforms, including the iPhone and the Wii, and comes with its own built-in Mono cross-compilation environment.

Nowadays, thank to Unity 3D, there are over 40 apps (mostly games) on App Store that were written in C# and that carry mono framework inside. Wouldn’t it be great if Apple included that in the firmware? Imagine that if we have these 40 apps installed, it’s 40 times the same framework consuming space and no need for that. But that’s asking too much, right? :)

WPF Textbox changing validation

Here's how to ensure that databinding happens when the value of a textbox changes. (as apposed to loosing forcus for example)

<TextBox Text="{Binding Interval, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"  />