In this instance, apparently the count was 2.

If a second comment was not a reply to a first comment (which from the structure of the UI, I don’t believe it was), why indicate “this comment has been removed” and include it in the count? 

Aye. Programmers. Can’t live with them. Can’t live without them.

But, in the mean time, feel free to follow me on twitter: wiredprairie. Maybe I’ll see you on twitter!

I promise not to tweet too much. Certainly not too much about bowel movements or the details of the meals that preceded them.

A few facts:

• I’m a competent Silverlight developer. I’ve even dabbled in XNA.
• I’m an owner of a iPhone 3GS.
• I would like a new phone.
• I’d like to buy a phone powered by the Windows Phone 7 OS when it’s made available.
• I’d like to make some free applications for my phone and others to use. A few for hobbies (like photography), and a few utilities for myself for work.
• I don’t however want to spend $99 a year for the privilege of doing so.

Why not open it up for people like myself?

Here’s a few alternatives:

• Make it free for those who make only free applications
• Make it free for those who agree to include a Bing-Ad placement component in the application, in a prominent position.
• Make it free for those who buy a copy of Visual Studio 2010 and Blend (like myself – I don’t use the Express editions).
• Make it free so that there’s no barrier to entry – that people and companies don’t need to worry about the extra fee – just jump on the Windows Phone 7 bandwagon.

Without this change, I probably won’t buy a Windows Phone 7, and will start building more HTML 5 web apps, that will work just fine on my iPhone 3GS (powered by iOS4).

According to the Chrome Developer Tools, there are 590 DIVs (in my inbox)!

So, are DIVs really better than TABLEs? Tables would be used to present data, and not just for layout in the case of Gmail.

Gmail has 11 TABLE elements on the page:

What would you do if you were creating a messaging application like Gmail?

Someone on StackOverflow asked how to bind a collection of items to a ListBox in Silverlight where the IsSelected property of the ListBoxItem is bound to an IsSelected property of the data item.

WPF has the native ability within a style to set the a style’s setter property IsSelected to a value of the two way binding to an IsSelected Property. Slick.

Silverlight, has no such thing unfortunately.

But, there’s a work around that isn’t too awful. Seriously.

What I’ve done is mapped the look and feel of the ListBoxItem selection to the DataTemplate for the item and removed it from the standard ListBoxItemContainer style:

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:TestSilverlightTodoListItem" xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions" x:Class="TestSilverlightTodoListItem.MainPage"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <UserControl.Resources>        

        <local:PeopleList x:Key="PeopleListDataSource" d:IsDataSource="True"/>        

        <Style x:Key="ListBoxItemStyle1" TargetType="ListBoxItem">
            <Setter Property="Padding" Value="3"/>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="VerticalContentAlignment" Value="Top"/>
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="TabNavigation" Value="Local"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ListBoxItem">
                        <Grid Background="{TemplateBinding Background}">
                            <VisualStateManager.VisualStateGroups>
                                <VisualStateGroup x:Name="CommonStates">
                                    <VisualState x:Name="Normal"/>
                                    <VisualState x:Name="MouseOver">
                                    </VisualState>
                                    <VisualState x:Name="Disabled">
                                    </VisualState>
                                </VisualStateGroup>
                                <VisualStateGroup x:Name="SelectionStates">
                                    <VisualState x:Name="Unselected"/>
                                    <VisualState x:Name="Selected">
                                    </VisualState>
                                </VisualStateGroup>
                                <VisualStateGroup x:Name="FocusStates">
                                    <VisualState x:Name="Focused">
                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="FocusVisualElement">
                                                <DiscreteObjectKeyFrame KeyTime="0">
                                                    <DiscreteObjectKeyFrame.Value>
                                                        <Visibility>Visible</Visibility>
                                                    </DiscreteObjectKeyFrame.Value>
                                                </DiscreteObjectKeyFrame>
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="Unfocused"/>
                                </VisualStateGroup>
                            </VisualStateManager.VisualStateGroups>
                            <ContentPresenter x:Name="contentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}"/>
                            <Rectangle x:Name="FocusVisualElement" RadiusY="1" RadiusX="1" Stroke="#FF6DBDD1" StrokeThickness="1" Visibility="Collapsed"/>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

        <DataTemplate x:Key="PersonTemplate">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>
                <i:Interaction.Behaviors>
                    <ei:DataStateBehavior Binding="{Binding IsSelected, Mode=TwoWay}" Value="True" TrueState="Selected" FalseState="Unselected"/>
                </i:Interaction.Behaviors>
                <VisualStateManager.VisualStateGroups>
                    <VisualStateGroup x:Name="Selection">
                        <VisualStateGroup.Transitions>
                            <VisualTransition GeneratedDuration="0:0:0.25"/>
                        </VisualStateGroup.Transitions>
                        <VisualState x:Name="Selected">
                            <Storyboard>
                                <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="fillColor" d:IsOptimized="True"/>
                                <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="fillColor2" d:IsOptimized="True"/>
                            </Storyboard>
                        </VisualState>
                        <VisualState x:Name="Unselected"/>
                    </VisualStateGroup>
                </VisualStateManager.VisualStateGroups>
                <VisualStateManager.CustomVisualStateManager>
                    <ei:ExtendedVisualStateManager/>
                </VisualStateManager.CustomVisualStateManager>
                <Rectangle x:Name="fillColor" Fill="#FFBADDE9" IsHitTestVisible="False" Opacity="0" RadiusY="1" RadiusX="1" Grid.ColumnSpan="2"/>
                <Rectangle x:Name="fillColor2" Fill="#FFBADDE9" IsHitTestVisible="False" Opacity="0" RadiusY="1" RadiusX="1" Grid.ColumnSpan="2"/>
                <CheckBox IsChecked="{Binding IsSelected, Mode=TwoWay}" Grid.ColumnSpan="1"/>
                <TextBlock x:Name="textBlock" Text="{Binding Name}" Grid.Column="1"/>
            </Grid>
        </DataTemplate>
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="White" DataContext="{Binding Source={StaticResource PeopleListDataSource}}" >
        <ListBox x:Name="myList" ItemsSource="{Binding}"
            ItemContainerStyle="{StaticResource ListBoxItemStyle1}"
            ItemTemplate="{StaticResource PersonTemplate}"
            SelectionMode="Multiple" />
    </Grid>
</UserControl>

The real magic is using the DataStateBehavior (which is included in the Blend 4.0 SDK):

<i:Interaction.Behaviors>
    <ei:DataStateBehavior Binding="{Binding IsSelected, Mode=TwoWay}" Value="True" TrueState="Selected" FalseState="Unselected"/>
</i:Interaction.Behaviors>

This ties the IsSelected property of the Person class (see below) to two VisualStates that I defined in the DataTemplate. A “Selected” and an “Unselected” state.

I grabbed the rectangle from the standard ListBoxItem container template template.

In the code behind, I wired up the selection changed event:

public partial class MainPage : UserControl
{
    private PeopleList _items = new PeopleList();

    public MainPage()
    {
        this.DataContext = _items;
        InitializeComponent();
        myList.SelectionChanged += new SelectionChangedEventHandler(myList_SelectionChanged);
    }

    void myList_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        // these both just need to toggle
        foreach (object o in e.AddedItems)
        {
            Person p = o as Person;
            p.IsSelected = !p.IsSelected;
        }
        foreach (object o in e.RemovedItems)
        {
            Person p = o as Person;
            p.IsSelected = !p.IsSelected;
        }
    }

    void myList_KeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Space  )
        {
            if (e.OriginalSource is ListBoxItem)
            {
                Person p = (e.OriginalSource as ListBoxItem).DataContext as Person;
                if (p != null)
                {
                    p.IsSelected = !p.IsSelected;
                }
            }
        }
    }
}

The selection changed toggles the state of each item. Without doing that, the selection doesn’t behave correctly. The SelectedItems list on the listbox no longer reflects the reality of the bound data items – but that shouldn’t matter in this case as the property of the item reflects the real state accurately.

For testing:

public class PeopleList : ObservableCollection<Person>
{
    public PeopleList()
    {
      this.Add( new Person { Name = "Henry", IsSelected = true });
      this.Add(new Person { Name = "Bonnie", IsSelected = true });
      this.Add( new Person { Name = "Clyde", IsSelected = false });
      this.Add( new Person { Name = "Ervin", IsSelected = false });
      this.Add( new Person { Name = "Timmy", IsSelected = true });
      this.Add( new Person { Name = "Jane", IsSelected = true });

    }
}

And:

public class Person : INotifyPropertyChanged
{
    private bool _isSelected;
    private string _name;

    public string Name
    {
        get { return _name; }
        set
        {
            if (value != _name)
            {
                _name = value;
                RaisePropertyChanged("Name");
            }
        }
    }

    public bool IsSelected
    {
        get { return _isSelected; }
        set
        {
            if (_isSelected != value)
            {
                _isSelected = value;
                RaisePropertyChanged("IsSelected");
            }
        }
    }

    private void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

    }

    public event PropertyChangedEventHandler PropertyChanged;
}

The question was essentially, “what’s a way to use DataTriggers in Silverlight, without DataTriggers?”

I had suggested one idea would just to use VisualStates and a code behind file.

That’s what I’ve done here. I created an enum of type AnimateState, which has three possible values, Top, Left, and Right. By clicking on one of three buttons on the simple UI, it changes the value of the property, which in turn calls one of the VisualStates defined in the XAML.

In the example, it animates the position of the orange ellipse to various positions on the canvas.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace DemoShowVisualStateManager
{
    public partial class MainPage : UserControl
    {
        private AnimateState _animateState;

        public MainPage()
        {
            InitializeComponent();
        }

        public AnimateState State
        {
            get { return _animateState; }

            set
            {
                if (_animateState != value && Enum.IsDefined(typeof(AnimateState), value))
                {
                    _animateState = value;

                    VisualStateManager.GoToState(this, value.ToString(), true);
                }
            }

        }

        private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
        {
            AnimateState state;
            if (AnimateState.TryParse((sender as Button).Content.ToString(), out state))
            {
                State = state;
            }

        }
    }

    public enum AnimateState
    {
        Top,
        Left,
        Right
    }
}

<UserControl x:Class="DemoShowVisualStateManager.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Width="500" Height="500">

    <UserControl.Resources>
    </UserControl.Resources>
    <Canvas x:Name="LayoutRoot" Background="White">
        <VisualStateManager.VisualStateGroups>
            <VisualStateGroup x:Name="Positions">
                <VisualStateGroup.Transitions>
                    <VisualTransition GeneratedDuration="0:0:3"/>
                </VisualStateGroup.Transitions>
                <VisualState x:Name="Right">
                    <Storyboard>
                        <DoubleAnimation Duration="0" To="389" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateY)" Storyboard.TargetName="ball" d:IsOptimized="True"/>
                        <DoubleAnimation Duration="0" To="198" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateX)" Storyboard.TargetName="ball" d:IsOptimized="True"/>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Left">
                    <Storyboard>
                        <DoubleAnimation Duration="0" To="-199" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateX)" Storyboard.TargetName="ball" d:IsOptimized="True"/>
                        <DoubleAnimation Duration="0" To="390" Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.TranslateY)" Storyboard.TargetName="ball" d:IsOptimized="True"/>
                    </Storyboard>
                </VisualState>
                <VisualState x:Name="Top"/>
            </VisualStateGroup>
        </VisualStateManager.VisualStateGroups>

        <Ellipse x:Name="ball" Stroke="#FFFFD9B8" RenderTransformOrigin="0.5,0.5" Height="100" VerticalAlignment="Top" Canvas.Top="10" Width="100" Canvas.Left="200">
            <Ellipse.RenderTransform>
                <CompositeTransform/>
            </Ellipse.RenderTransform>
            <Ellipse.Fill>
                <RadialGradientBrush Center="0.388,0.328" GradientOrigin="0.388,0.328" RadiusX="0.63">
                    <GradientStop Color="#FFF97200" Offset="1"/>
                    <GradientStop Color="#FFFFD9B8"/>
                </RadialGradientBrush>
            </Ellipse.Fill>
        </Ellipse>
        <Button Content="Left" Height="33" Canvas.Left="200" Canvas.Top="229" Width="100" Click="Button_Click"/>
        <Button Content="Top" Height="33" Canvas.Left="200" Canvas.Top="266" Width="100" Click="Button_Click"/>
        <Button Content="Right" Height="33" Canvas.Left="200" Canvas.Top="303" Width="100" Click="Button_Click"/>

    </Canvas>
</UserControl>

The addin, called Settings Swapper may be downloaded from CodePlex and is licensed using the new BSD license.

The documentation is here.

The settings he used for MVC pages are included in the documentation. If you have any questions or issues, either leave a comment here or add something to codeplex.

Enjoy.

IIS Express will become a new way for developers to do local web development in a safe, administrative-account-free way, yet get the full experience of IIS 7. I’d bet the days of the ASP.NET Development server are numbered if IIS Express actually works as well as is suggested (if the same debug/test/run cycle is maintained, and the perf is good, I can’t see any reason why not).

The only bad news is that the announcement precedes the availability of IIS Express and also precedes the availability of patches for VS 2010 to make integration with this new option simple. The latter sounds like it’s farther out than IIS Express itself.

I’d like to see a feature for allowing the web sites hosted within IIS Express to be available from other machines and not just localhost. It would make sharing current development with other team members, QA, managers, etc., much simpler. For developers on older versions of Windows (like XP), they have no option for locally hosting a IIS7 web site and showing it to others. (From the initial blog post, it’s not mentioned if this scenario is supported).

It usually works for me.

The stack dump from the mini-dump taken by Visual Studio isn’t real enlightening. Things went wrong.

     ntdll.dll!@RtlpLowFragHeapFree@8()  + 0×89 bytes   
     ntdll.dll!_RtlFreeHeap@12()  + 0x7e bytes   
     apphelp.dll!_SdbFree@4()  + 0×22 bytes   
     apphelp.dll!_HashFree@4()  + 0x3c bytes   
     apphelp.dll!_SdbpReleaseSearchDBContext@4()  + 0x6d bytes   
     apphelp.dll!_SdbGetMatchingExeEx@32()  + 0x2b9 bytes   
     apphelp.dll!_InternalCheckRunApp@76()  + 0x21c bytes   
     apphelp.dll!_ApphelpCheckRunAppEx@56()  + 0xa7 bytes   
     kernel32.dll!_BaseRestoreImpersonation@4()  – 0x75d55 bytes   
     kernel32.dll!_BaseCheckRunApp@52()  + 0×46 bytes   
     kernel32.dll!_BasepCheckBadapp@60()  + 0x1a1 bytes   
     kernel32.dll!_BasepQueryAppCompat@68()  + 0×63 bytes   
     kernel32.dll!_CreateProcessInternalW@48()  + 0×961 bytes   
>    kernel32.dll!_CreateProcessInternalA@48()  + 0×123 bytes   
     kernel32.dll!_CreateProcessA@40()  + 0x2c bytes   
     devenv.exe!DwCreateProcess()  + 0xc0 bytes   
     devenv.exe!LaunchWatson()  + 0x2b2 bytes   
     devenv.exe!DwExceptionFilterEx()  + 0xed bytes   
     devenv.exe!DwExceptionFilter()  + 0x1f bytes   
     mscoreei.dll!InternalUnhandledExceptionFilter()  + 0x1c bytes   
     kernel32.dll!_UnhandledExceptionFilter@4()  + 0x5e2 bytes   
     ntdll.dll!___RtlUserThreadStart@8()  + 0x369cc bytes   
     ntdll.dll!@_EH4_CallFilterFunc@8()  + 0×12 bytes   
     ntdll.dll!ExecuteHandler2@20()  + 0×26 bytes   
     ntdll.dll!ExecuteHandler@20()  + 0×24 bytes   
     ntdll.dll!_KiUserExceptionDispatcher@8()  + 0xf bytes   
     ntdll.dll!@RtlpLowFragHeapFree@8()  + 0×89 bytes   
     ntdll.dll!_RtlFreeHeap@12()  + 0x7e bytes   
     ole32.dll!CRetailMalloc_Free()  + 0x1c bytes   
     ole32.dll!_CoTaskMemFree@4()  + 0×13 bytes   
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0daff77b()    
     [Frames below may be incorrect and/or missing, no symbols loaded for Microsoft.VisualStudio.Editor.Implementation.ni.dll]   
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0daff77b()    
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0dafdfcd()    
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0daff642()    
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0dafdfcd()    
     cslangsvc.dll!CEditFilter::QueryStatus()  + 0x13c bytes   
     cslangsvc.dll!CVsEditFilter::QueryStatus()  + 0×95 bytes   
     mscorlib.ni.dll!5af61753()    
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0dae99eb()    
     Microsoft.VisualStudio.Editor.Implementation.ni.dll!0dae9a1c()    
     Microsoft.VisualStudio.Platform.WindowManagement.ni.dll!6dce2ae4()    
     Microsoft.VisualStudio.Platform.WindowManagement.ni.dll!6dcdf98c()    
     msenv.dll!CVSCommandTarget::QueryStatusCmd()  + 0x423c bytes   
     msenv.dll!`anonymous namespace’::QueryStatusForController()  + 0×63 bytes   
     msenv.dll!`anonymous namespace’::GetQueryStatusFlags()  + 0x3a bytes   
     msenv.dll!CSurfaceCommandingSupport::IsCommandEnabled()  + 0x1bbb bytes   
     msenv.dll!`anonymous namespace’::DoCommonStateUpdating<CommandUI::Models::IButtonController,`anonymous namespace’::<lambda1> >()  + 0xa2 bytes   
     msenv.dll!CUpdateVisitor::VisitButtonController()  + 0x1b bytes   
     msenv.dll!CControllerVisitorBase::DispatchVisit()  + 0x3bf bytes   
     msenv.dll!CControllerVisitorBase::VisitController()  + 0×22 bytes   
     msenv.dll!CSurfaceCommandingSupport::Update()  + 0x2e bytes   
     msenv.dll!CommandUI::Models::Impl::CControllerBase::Update()  + 0×21 bytes   
     msenv.dll!UpdateChildCollectionWithSeparators()  + 0x17f bytes   
     msenv.dll!CUpdateVisitor::VisitToolBarController()  + 0x2a6 bytes   
     msenv.dll!CControllerVisitorBase::DispatchVisit()  + 0×226 bytes   
     msenv.dll!CControllerVisitorBase::VisitController()  + 0×22 bytes   
     msenv.dll!CSurfaceCommandingSupport::Update()  + 0x2e bytes   
     msenv.dll!UpdateCommandModels()  + 0×147 bytes   
     msenv.dll!CmdUpdateForceInternal()  + 0×28 bytes   
     msenv.dll!CMsoComponent::FDoNonPeriodicIdle()  + 0×991 bytes   
     msenv.dll!CMsoComponent::FDoIdle()  + 0×17 bytes   
     msenv.dll!SCM::FDoIdleLoop()  + 0xf3 bytes   
     msenv.dll!SCM::FDoIdle()  + 0xc7 bytes   
     msenv.dll!SCM_MsoStdCompMgr::FDoIdle()  + 0×13 bytes   
     msenv.dll!CMsoCMHandler::EnvironmentMsgLoop()  + 0x74a bytes   
     msenv.dll!CMsoCMHandler::FPushMessageLoop()  + 0×79 bytes   
     msenv.dll!SCM::FPushMessageLoop()  + 0x8c bytes   
     msenv.dll!SCM_MsoCompMgr::FPushMessageLoop()  + 0x2a bytes   
     msenv.dll!CMsoComponent::PushMsgLoop()  + 0×28 bytes   
     msenv.dll!VStudioMainLogged()  + 0x22a bytes   
     msenv.dll!_VStudioMain()  + 0×78 bytes   
     devenv.exe!util_CallVsMain()  + 0xdb bytes   
     devenv.exe!CDevEnvAppId::Run()  + 0×693 bytes   
     devenv.exe!_WinMain@16()  + 0×88 bytes   
     devenv.exe!operator new[]()  + 0xa59d bytes   
     kernel32.dll!@BaseThreadInitThunk@12()  + 0×12 bytes   
     ntdll.dll!___RtlUserThreadStart@8()  + 0×27 bytes   
     ntdll.dll!__RtlUserThreadStart@8()  + 0x1b bytes