Re: Bind to converter in XAML - WPF Discussion Boards

Re: Bind to converter in XAML [modified]

13-Jul-11 9:54

Hey all,

I'm running into a problem when binding a property of a GroupItemTemplate (in the WP7 LongListSelector) to a converter I built. I want the converter to check if there are items to be displayed in the group, and according to if there are items, set a Brush to the background.

This is my code for the Converter:

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value is Group<TrackInfo>)
            {
                Group<TrackInfo> group = value as Group<TrackInfo>;
                if (group != null)
                {
                    if (group.Items.Count == 0)
                        return (SolidColorBrush)Application.Current.Resources["PhoneChromeBrush"];
                    else
                        return (SolidColorBrush)Application.Current.Resources["PhoneAccentBrush"];
                }
            }

            return new SolidColorBrush(Color.FromArgb(128, 255, 0, 0));
        }

And this is in my XAML:

<DataTemplate x:Key="groupItemTemplate">
            <Border Width="99" Height="99" Background="{Binding Converter={StaticResource groupItemBackgroundBrush}}" Margin="6" IsHitTestVisible="{Binding HasItems}">
                <TextBlock Text="{Binding GroupTitle}" 
                                       FontFamily="{StaticResource PhoneFontFamilySemiBold}"
                                       FontSize="36"
                                       Margin="{StaticResource PhoneTouchTargetOverhang}"
                                       Foreground="{StaticResource PhoneForegroundBrush}"                                        
                                       VerticalAlignment="Bottom"/>
            </Border>
        </DataTemplate>
        
        <valueConverters:TrackGroupToGroupItemBackgroundBrushConverter x:Key="groupItemBackgroundBrush" />

...

<toolkit:LongListSelector x:Name="lstTracks"  Height="800" Width="480" DisplayAllGroups="True"
        ListHeaderTemplate="{StaticResource listHeader}"
        ListFooterTemplate="{StaticResource listFooter}"
        ItemTemplate="{StaticResource itemTemplate}"
        GroupHeaderTemplate="{StaticResource groupHeaderTemplate}"
        GroupItemTemplate="{StaticResource groupItemTemplate}">
        <toolkit:LongListSelector.GroupItemsPanel>
            <ItemsPanelTemplate>
                <toolkit:WrapPanel Orientation="Horizontal" />
            </ItemsPanelTemplate>
        </toolkit:LongListSelector.GroupItemsPanel>
    </toolkit:LongListSelector>

I get an Unspecified Error, wich isn't exactly quite helpful... Is there a better way to find out if the group has items and accordingly set a Brush? Or is there an error in my code I don't see?

Thanks for helping,
MadMatt

Mark Salsbery13-Jul-11 11:27

13-Jul-11 11:27

You need to have the converter instance in resources somewhere visible to the datatemplate (just like the other static resources you are binding to) so the StaticResource binding works.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Wednesday, July 13, 2011 5:58 PM

_Madmatt13-Jul-11 23:41

13-Jul-11 23:41

The DataTemplate as well as the Converter are in the

    <phone:PhoneApplicationPage.Resources>
<DataTemplate x:Key="groupItemTemplate">
            <Border Width="99" Height="99" Background="{Binding Converter={StaticResource groupItemBackgroundBrush}}" Margin="6" IsHitTestVisible="{Binding HasItems}">
                <TextBlock Text="{Binding GroupTitle}" 
                                       FontFamily="{StaticResource PhoneFontFamilySemiBold}"
                                       FontSize="36"
                                       Margin="{StaticResource PhoneTouchTargetOverhang}"
                                       Foreground="{StaticResource PhoneForegroundBrush}"                                        
                                       VerticalAlignment="Bottom"/>
            </Border>
        </DataTemplate>
        
        <valueConverters:TrackGroupToGroupItemBackgroundBrushConverter x:Key="groupItemBackgroundBrush" />
    </phone:PhoneApplicationPage.Resources>

Is there something wrong in here?

Pete O'Hanlon14-Jul-11 0:02

Pete O'Hanlon

14-Jul-11 0:02

_Madmatt wrote:
Background="{Binding Converter={StaticResource groupItemBackgroundBrush}}"

The problem here is that you haven't told the converter what it should bind to. Try changing this to be

"{Binding Path=., Converter={StaticResource groupItemBackgroundBrush}}"

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

_Madmatt14-Jul-11 0:29

14-Jul-11 0:29

No, still getting the exception with this setting... Frown | :(

Pete O'Hanlon14-Jul-11 0:53

Pete O'Hanlon

14-Jul-11 0:53

Put a breakpoint in your converter and see if it gets hit. Then step over the code to see what breaks.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

_Madmatt14-Jul-11 1:27

14-Jul-11 1:27

It's not even hitting the converter! Frown | :(

Not with this XAML:

<phone:PhoneApplicationPage.Resources>
<DataTemplate x:Key="groupItemTemplate">
            <Border Width="99" Height="99" Background="{Binding Path=., Converter={StaticResource groupItemBackgroundBrush}}" Margin="6" IsHitTestVisible="{Binding HasItems}">
                <TextBlock Text="{Binding GroupTitle}" 
                                       FontFamily="{StaticResource PhoneFontFamilySemiBold}"
                                       FontSize="36"
                                       Margin="{StaticResource PhoneTouchTargetOverhang}"
                                       Foreground="{StaticResource PhoneForegroundBrush}"                                        
                                       VerticalAlignment="Bottom"/>
                <Border.Resources>
                    <valueConverters:TrackGroupToGroupItemBackgroundBrushConverter x:Key="groupItemBackgroundBrush" />
                </Border.Resources>
            </Border>
        </DataTemplate>

        
    </phone:PhoneApplicationPage.Resources>

And not with this one too:

<phone:PhoneApplicationPage.Resources>
    <DataTemplate x:Key="groupItemTemplate"
            <Border Width="99" Height="99" Background="{Binding Path=., Converter={StaticResource groupItemBackgroundBrush}}" Margin="6" IsHitTestVisible="{Binding HasItems}">
                <TextBlock Text="{Binding GroupTitle}" 
                                       FontFamily="{StaticResource PhoneFontFamilySemiBold}"
                                       FontSize="36"
                                       Margin="{StaticResource PhoneTouchTargetOverhang}"
                                       Foreground="{StaticResource PhoneForegroundBrush}"                                        
                                       VerticalAlignment="Bottom"/>
                            </Border>
        </DataTemplate>

<valueConverters:TrackGroupToGroupItemBackgroundBrushConverter x:Key="groupItemBackgroundBrush" />        

    </phone:PhoneApplicationPage.Resources>

skv_lviv14-Jul-11 20:01

skv_lviv

14-Jul-11 20:01

Not sure, maybe I'm wrong, but have you tried to put converter definition before your datatemplate?

_Madmatt17-Jul-11 0:23

17-Jul-11 0:23

Thanks! This did the trick! Too bad I didn't think of that myself... Big Grin | :-D

Abhinav S13-Jul-11 20:44

Abhinav S

13-Jul-11 20:44

Try by making this line - <valueConverters:TrackGroupToGroupItemBackgroundBrushConverter x:Key="groupItemBackgroundBrush" />; part of the Itemsources or UserControls resource.

_Madmatt13-Jul-11 23:43

13-Jul-11 23:43

They are both part of the <phone:PhoneApplicationPage.Resources>, I cannot create a <DataTemplate.Resources>, so where should I put it else? This is quite confusing to me, it's the first time is use XAML binding in such a complex way...

Thanks

Membership Role

picasso212-Jul-11 17:24

picasso2

12-Jul-11 17:24

I have created simple SL business application. I am trying to learn membership and authentication and configured the following:
1. Install the ASPNETDB

2. Part of the Web.config looks like this
<roleManager enabled="true" />;
<authentication mode="Forms">;
<forms name=".Test_ASPXAUTH" />;
</authentication&gt>
<profile>
<properties>
<add name="FriendlyName" />
</properties>
</profile>
</system.web>
<connectionStrings>
<remove name="LocalSqlServer" />
<add name="LocalSqlServer" connectionString="Data Source=TPSA11;Initial Catalog=aspnetdb;Integrated Security=True" />
<add name="TestEntities" connectionString="metadata=res://*/TestModel.csdl|res://*/TestModel.ssdl|res://*/TestModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=TPSA11;Initial Catalog=Test;Persist Security Info=True;User ID=sa;Password=service;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />
</connectionStrings>
</configuration>

3. In App.Xamel.cs

InitializeComponent();
WebContext webContext = new WebContext();
webContext.Authentication = new FormsAuthentication();

4. The home page contains a datagrid that gets populated but to force authentication I added

[RequiredRole(“ADMIN”)]
Before the query used to populate the datagrid.

When I execute the application within VS2010 (debug mode), the datagrid is empty until a login with credentials with ADMIN role then it gets populated.—so far so god.
But when I run the application outside VS (e.g. http://servername:port/testApp.html the datagrid is loaded by default . If I try to login anyways, I get an error:

“Load operation failed for query “login” “System.ServiceModel.DomainServices.Client.DomianOperation” was thrown”

This is also captured using fiddler:

@_Fault_5http://schemas.microsoft.com/ws/2005/05/envelope/none@_Code@_Value_Sender_@_Reason@_Text__xml_lang_en-US>Login and Logout can only be invoked for Forms authentication._@_Detail@_DomainServiceFault__DomainServices _i)http://www.w3.org/2001/XMLSchema-instance@ ErrorCode_@
ErrorMessage>Login and Logout can only be invoked for Forms authentication.@_IsDomainException@
StackTraceL_ at System.ServiceModel.DomainServices.Server.ApplicationServices.AuthenticationBase`1.Login(String userName, String password, Boolean isPersistent, String customData)
at Login(DomainService , Object[] )
at System.ServiceModel.DomainServices.Server.ReflectionDomainServiceDescriptionProvider.ReflectionDomainOperationEntry.Invoke(DomainService domainService, Object[] parameters)
at System.ServiceModel.DomainServices.Server.DomainOperationEntry.Invoke(DomainService domainService, Object[] parameters, Int32& totalCount)
at System.ServiceModel.DomainServices.Server.DomainService.Query(QueryDescription queryDescription, IEnumerable`1& validationErrors, Int32& totalCount)
at System.ServiceModel.DomainServices.Hosting.QueryProcessor.Process[TEntity](DomainService domainService, DomainOperationEntry queryOperation, Object[] parameters, ServiceQuery serviceQuery, IEnumerable`1& validationErrors, Int32& totalCount)

Any help is greatly appreciated

Mark Salsbery13-Jul-11 11:56

13-Jul-11 11:56

When you run in the debugger (and it works) what is the service host? IIS? Development server?

It looks like whatever host you are using when the failure occurs isn't configured properly for forms authentication.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

picasso213-Jul-11 20:22

picasso2

13-Jul-11 20:22

Hi Mark,
They are different. The connection used when debugging in VS2010 uses a dynamic port (http://servername:58357/MySite/MyFileTest.html)

The actual site is http://mySite/MyFile.html

I have tried:
1. disable all authentication except FORM and anonymous
2. The application pool is configured as Integrated NET 4.0

still error
"Failure using default "membership". Make sure is configured correctly. Login failed for IIS AAPPOOL\MySite

thannX

Mark Salsbery14-Jul-11 10:50

14-Jul-11 10:50

Ok, so hosting in debugger you are using the Visual Studio test server and the other is on IIS, correct (what server host you are using is important!)?

If the above is correct then you haven't configured IIS correctly. The authorization and role manager need to be setup. If you're using SQL Server (Express is fine) to store user/role info then that needs to be configured for your app if you haven't done so already. There's a Aspnet_regsql.exe utility to do it for you.

Then you need to configure the manager(s) to use your database by supplying a connection string. IIS uses "LocalSqlServer" by default so you should have that covered as long as your "LocalSqlServer" connection string connects to a valid IIS/ASP.NET configured database.

For what it's worth, here's an example of one of my configurations...note I do NOT use the default connection string name here so I have to specify the connection string for each provider...

<?xml version="1.0"?>

<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->

<configuration>

  <appSettings>
  </appSettings>

  <connectionStrings>
    <remove name="LocalSqlServer" />
    <add name="MyConnectionString" connectionString="Data Source=localhost;Initial Catalog=myCatalog;Integrated Security=True" providerName="System.Data.SqlClient" />
  </connectionStrings>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <authorization>
      <!--
      <deny users="?" />
      -->
      <allow users="*" />
    </authorization>
    <authentication mode="Forms" >
      <forms name="MyFormsName" timeout="30" />
    </authentication>
    <membership defaultProvider="TheSqlMembershipProvider"
                hashAlgorithmType=""
                userIsOnlineTimeWindow="15" >
      <providers>
        <clear/>
        <add name="TheSqlMembershipProvider"
             type="System.Web.Security.SqlMembershipProvider, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
             connectionStringName="MyConnectionString"
             applicationName="/"
             enablePasswordRetrieval="false"
             enablePasswordReset="true"
             requiresQuestionAndAnswer="true"
             requiresUniqueEmail="false"
             passwordFormat="Hashed"
             maxInvalidPasswordAttempts="5"
             passwordAttemptWindow="10"
             minRequiredNonalphanumericCharacters="1"
             minRequiredPasswordLength="7"
             passwordStrengthRegularExpression="" />
      </providers>
    </membership>
    <roleManager enabled="true"
                 defaultProvider="TheSqlRoleProvider"
                 cacheRolesInCookie="false"
                 cookieName=".ASPXROLES"
                 cookiePath="/"
                 cookieProtection="All"
                 cookieRequireSSL="false"
                 cookieSlidingExpiration="true"
                 cookieTimeout="30"
                 createPersistentCookie="false"
                 domain=""
                 maxCachedResults="25" >
      <providers>
        <clear />
        <add name="TheSqlRoleProvider"
             type="System.Web.Security.SqlRoleProvider, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
             connectionStringName="MyConnectionString"
             applicationName="/" />
      </providers>
    </roleManager>
    <profile enabled="true"
             defaultProvider="TheSqlProfileProvider"
             automaticSaveEnabled="true" >
      <providers>
        <clear />
        <add name="TheSqlProfileProvider"
             type="System.Web.Profile.SqlProfileProvider, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
             connectionStringName="MyConnectionString"
             applicationName="/" />
      </providers>
      <properties>
        <add name="FriendlyName"/>
        <add name="ZipCode" />
        <add name="CityAndState" />
      </properties>
    </profile>
  </system.web>

  <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
  </system.serviceModel>
</configuration>

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Mark Salsbery14-Jul-11 10:55

Why does Microsoft do this to me

14-Jul-11 10:55

Some more info...

Explained: Forms Authentication in ASP.NET 2.0[^]
How To: Use Role Manager in ASP.NET 2.0[^]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Tad McClellan12-Jul-11 12:58

Tad McClellan

12-Jul-11 12:58

So each version of Silverlight that comes out I take a look and see how the technology is progressing. I finally got to SL4. This may be user error but I'm really frustrated with the data access. I first tried POCO, using my own objects from the server. Got those passed through WCF and bound but then you can't use the DataAnnotations (I like the ID of having the validations for the data where the data lives in the class) when you bind on the client. Then I went to the WFC Data Service model using MVVM. Looked good but then guess what, same issue. Lastly I went to RIA but couldn't figure out how to add an object on the client. Evidently MS didn't build my Insert function on the Domain Service. So I went to go look for myself. So many generated functions with odd attributes my eyes hurt. I’ve looked at videos which all simply just edit objects but don’t add anything. But if they would I can get the DataAnnotations working with RIA but I have to do this kludgy Metadata object.

So is there a better way or am I doing something wrong? I hate MS generated black boxes because they tend not to work for real applications and then when something does go bump in them you spend hours on google researching only to find out you are so in bed with them you have to wait till next release to get it fixed. I’m just about to create my own Data layer architecture for working with SL but before I do I thought I would do a sanity check with the guru’s. What did I miss? Is there a better way?

TadMcClellan.Com

Re: Why does Microsoft do this to me

Mark Salsbery13-Jul-11 11:51

Re: Why does Microsoft do this to me

13-Jul-11 11:51

WCF RIA Services will give you the most RAD help with dataannotations.

The metadata object may seem kludgy but it's not so bad. The code it is decorating is Visual Studio generated code that you shouldn't edit anyway so it doesn't really make a difference because you're not editing same code in more than one place.

You're still responsible for adding CRUD operations to the service yourself, so if the default generated code doesn't include an insert method then you simply add one yourself. Generally you'll end up adding lots of variations on insert, delete, and add service methods.

And there's no black box here. All the generated code is part of your project.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Mycroft Holmes14-Jul-11 12:49

Mycroft Holmes

14-Jul-11 12:49

There never was a chance that we would use RIA, for the same reasons you iterate, black box, MS defined and constrained functionality etc. We built our own, first building a code generator (modified the existing one which began life in VB5) to service the WCF requirements. This is basically simple boilerplate code for the object and CRUD work.

This pushes 90% of our work into the VM and View, where we have some really cool snippets that eliminate all the donkey work and leaves us with the difficult stuff like making the dammed view do as it is told!

It is painful getting a design idea wrong, you should see the crap we (I) created around dialog management before I got a handle on the child window concept.

Never underestimate the power of human stupidity
RAH

How to draw a plus sign and triangles for buttons in WPF?

Member 297299212-Jul-11 10:18

Member 2972992

12-Jul-11 10:18

I am looking to use the shape functionality in WPF in order to apply two triangles one pointing up and the other pointing down along with the plus sign to some buttons. Having a look there doesn't seem to be an easy to do this. Does anyone have an example where this can be easily done?

Thank

Re: How to draw a plus sign and triangles for buttons in WPF?

Mark Salsbery12-Jul-11 10:59