Re: How to enable wpf controls through data binding on a selected item from a combo box [modified] - WPF Discussion Boards

15-Jul-11 6:11

One way is to bind IsEnabled on the control(s) to the ComboBox SelectedIndex or SelectedItem property using a value converter[^] on the binding to convert the Selectedxxx value to a bool.

[System.Windows.Data.ValueConversion(typeof(int), typeof(bool))]
public class SelectedIndexToIsEnabledConverter : System.Windows.Data.IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return ((int)value >= 0) ? true : false;
    }

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

    <UserControl.Resources >
        <local:SelectedIndexToIsEnabledConverter x:Key="SelectedIndexToIsEnabledConverter" />
    </UserControl.Resources>
...

Example binding:
    IsEnabled="{Binding Path=SelectedIndex,ElementName=comboBox1,Converter={StaticResource SelectedIndexToIsEnabledConverter},Mode=OneWay}"

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

modified on Friday, July 15, 2011 12:33 PM

Game algorithm problem

Neo1010115-Jul-11 4:05

Neo10101

15-Jul-11 4:05

Hello,

Could someone help me out here please.. I have a game algorithm problem: http://oi56.tinypic.com/29x6op0.jpg

Thank you

Mark Salsbery15-Jul-11 6:41

15-Jul-11 6:41

Please post on the algorithm board[^] if you want algorithms.

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

Abhinav S15-Jul-11 6:51

Abhinav S

15-Jul-11 6:51

Wrong forum.

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Too much of heaven, our life is all hell bound
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Neo1010119-Jul-11 0:02

Neo10101

19-Jul-11 0:02

Not wrong forum. The people from the algorithm forum sent me here.

Pete O'Hanlon19-Jul-11 1:46

Pete O'Hanlon

19-Jul-11 1:46

And yet you say you have a problem with an algorithm, ergo it's an algorithm forum post.

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WCF Async Call random response

Neo101017-Nov-11 0:25

Neo10101

7-Nov-11 0:25

A game algorithm in a Silverlight app.

NTheOne13-Jul-11 18:01

NTheOne

13-Jul-11 18:01

Hello All,

I have issue with WCF ASYNC call. WCF service give me a random response. Sometimes it gives me result and sometimes not. I have set max values for binding related properties.

Can anyone can help me to figure out this issue?

Thanks

Re: WCF Async Call random response

Abhinav S13-Jul-11 20:36

Abhinav S

13-Jul-11 20:36

This could be something to do with the timeout or buffer size.
Try changing these settings.

Too much of heaven can bring you underground
Heaven can always turn around
Too much of heaven, our life is all hell bound
Heaven, the kill that makes no sound

visualstudio/experssion blend

arkiboys13-Jul-11 10:31

arkiboys

13-Jul-11 10:31

Hi,
I wouold like to learn a little about how to design better UI in silverlight or WPF in visual studio.
1-
Is there a book to teach me that in visual studio xaml or should I buy a step by step book in expressin blend? I say expression blend because it seems that I can use the code in expression blend and paste the xaml into visual studio.

Thank you

Mark Salsbery13-Jul-11 11:24

13-Jul-11 11:24

I don't know a book to recommend, but you don't need to paste code into visual studio. Expression Blend works with Visual Studio solutions/projects so you can edit (and run) code in Blend and edit and debug in Visual Studio as well.

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

Abhinav S13-Jul-11 20:37

Abhinav S

13-Jul-11 20:37

To learn better design, Expression Blend would be a better bet than Visual Studio.
As already pointed out, you can edit xaml in Expression Blend as well.

Too much of heaven can bring you underground
Heaven can always turn around
Too much of heaven, our life is all hell bound
Heaven, the kill that makes no sound

Kunal Chowdhury «IN»20-Jul-11 0:19

Kunal Chowdhury «IN»

20-Jul-11 0:19

Yes "Good Answer". You can use Expression Blend to create the UI styles very easily which is very very difficult if you are using Visual Studio to design. Visual Studio requires depth knowledge on XAML. Also more effort is require if you are designing using the VS. Use Expression Blend which will help you a lot.

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Oludayo Alli20-Aug-11 7:15

Oludayo Alli

20-Aug-11 7:15

This could be a good starting point and it's free. Just go to Expression Blend Training[^]

arkiboys20-Aug-11 7:20

arkiboys

20-Aug-11 7:20

Thanks

Bind to converter in XAML

Oludayo Alli20-Aug-11 8:39

Oludayo Alli

20-Aug-11 8:39

You're welcome and that's what we're here for - to help!

_Madmatt13-Jul-11 9:54

_Madmatt

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

Re: Bind to converter in XAML [modified]

Mark Salsbery13-Jul-11 11:27