WPF Hyperlink Question - WPF Discussion Boards

24-Oct-11 9:51

I have styled a list so that the list items appear as hyperlinks. Here's my xaml:

<UserControl.Resources>

    <converters:ProjectTypeImageValueConverter x:Key="projectTypeConverter"/>

    <!--This is the template for the Recent projects list items-->
    <DataTemplate DataType="{x:Type local:RecentProjectModel}">
        <StackPanel Orientation="Horizontal"
                    Margin="2">
            <Image Source="{Binding ProjectType, Converter={StaticResource projectTypeConverter}}"
                    Margin="0,0,5,0"/>
            <TextBlock Width="150">
                <Hyperlink Foreground="RoyalBlue">
                    <TextBlock Text="{Binding Caption}"/>
                </Hyperlink>
            </TextBlock>
        </StackPanel>
    </DataTemplate>
        
</UserControl.Resources>

and

<ListBox x:Name="lstRecent"
            Grid.Row="1"
            Grid.Column="0"
            ItemsSource="{Binding RecentProjects}"
            SelectedItem="{Binding SelectedRecentProject}"
            BorderThickness="0"
            Margin="3"
            MinWidth="235"/>

When I click the link, the SelectedRecentProject is not set. If I click the image of the list item, it is set. How do I set the SelectedRecentProject when the link is clicked?

Thanks

Everything makes sense in someone's mind

Kevin Marois24-Oct-11 10:15

24-Oct-11 10:15

It doesn't work. No response.

Everything makes sense in someone's mind

SledgeHammer0124-Oct-11 10:11

24-Oct-11 10:11

Wow, I had to write a quick sample app for this one. The Hyperlink / TextBlock combo is eating the mouse down. You'll notice that the selection changed event never gets fired. You can set IsHitTestVisible="False" on the TextBlock (but you will lose the hand cursor)... or you need to derive a "HyperlinkEx" class from Hyperlink and set the focus to the parent yourself, or you can change controls to something else Smile | :)

. If you are OK with losing the hand cursor when they mouse over the link, the the IsHitTestVisible="False" is the quickest fix.

EDIT: actually, you probably need to do the derived class thing on TextBlock since Hyperlink isn't a UI element. Just derive a class from TextBlock and override PreviewMouseLeftButtonDown and chase up the visual tree til you hit the ListBoxItem. I whipped this out in a few seconds and it works without losing the hand cursor. I'll leave the clean up / error checking to you Smile | :)

.

public class TextBlockEx : TextBlock
{
public TextBlockEx()

: base()
{
this.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(HyperlinkEx_PreviewMouseLeftButtonDown);
//this.MouseLeftButtonDown += new MouseButtonEventHandler(HyperlinkEx_MouseLeftButtonDown);
}

void HyperlinkEx_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
object v = this;

while (v != null)
{
if (v is ListBoxItem)
{
((ListBoxItem)v).IsSelected = true;
((ListBoxItem)v).Focus();
break;
}
v = VisualTreeHelper.GetParent((DependencyObject)v);
}

e.Handled = true;
}
}

Kevin Marois24-Oct-11 10:16

24-Oct-11 10:16

ya, that did it. I'll deal with the cursor some other time. It's not that big of a deal right now.

Thanks

Everything makes sense in someone's mind

SledgeHammer0124-Oct-11 10:19

24-Oct-11 10:19

I edited the message as you responded... I've got the "TextBlockEx" working for you... just needs a bit of clean up Smile | :)

and doesn't lose the mouse cursor Smile | :)

Kevin Marois24-Oct-11 10:25

24-Oct-11 10:25

Excellent. I'll throw it in later today

Many thanks

Everything makes sense in someone's mind

Kevin Marois25-Oct-11 6:18

WPF Data Template Question

25-Oct-11 6:18

This worked perfectly. Thank you!!!

Everything makes sense in someone's mind

Kevin Marois24-Oct-11 7:37

24-Oct-11 7:37

I have this data template

HTML

<UserControl.Resources>
        
    <!--This is the template for the Recent projects list items-->
    <DataTemplate DataType="{x:Type local:RecentProjectModel}">
        <StackPanel Orientation="Horizontal">
            <Image Source="/...;component/Media/Graphics/abtech_triangle_blue_small.png"
                    Margin="0,0,5,0"/>
            <TextBlock Width="150">
                <Hyperlink>
                    <TextBlock Text="{Binding Caption}"/>
                </Hyperlink>
            </TextBlock>
        </StackPanel>
    </DataTemplate>
        
</UserControl.Resources>

I would like to change the image based off the value of a property called ProjectType on the RecentProjectModel class.

How do I do this?

Thanks

Everything makes sense in someone's mind

modified 24-Oct-11 13:44pm.

SledgeHammer0124-Oct-11 8:27

24-Oct-11 8:27

Just bind to ProjectType and use a value converter, or have your VM expose an ImageSource property and bind to that directly. Is your binding to Caption working? I seem to recall there are some issues when using binding inside of a data template, but I can't recall off the top of my head.

Kevin Marois24-Oct-11 8:30

24-Oct-11 8:30

Yes the caption is working.

Never used a converter before. Got an exmaple?

Everything makes sense in someone's mind

SledgeHammer0124-Oct-11 8:33

24-Oct-11 8:33

This has a simple example on both the C# side and the XAML side:

http://msdn.microsoft.com/en-us/library/system.windows.data.ivalueconverter.aspx[^]

Its just a method that WPF will pass in a ProjectType to and you will decide based on that what ImageSource you want to return... actually, I think just returning the URL string will work too.

modified 24-Oct-11 14:53pm.

Kevin Marois24-Oct-11 8:44

24-Oct-11 8:44

Ok I see.

Thanks

Everything makes sense in someone's mind

Kevin Marois24-Oct-11 9:09

24-Oct-11 9:09

That worked perfect - thanks

Everything makes sense in someone's mind

WPF MVVM Nested Views

Kevin Marois21-Oct-11 11:51

21-Oct-11 11:51

I want to "next" a child view inside a parent view. The child view will be removed from time to time and replace with other views.

How does the parent view know what child views properties change?

Thanks

Everything makes sense in someone's mind

SledgeHammer0121-Oct-11 12:05

21-Oct-11 12:05

Views shouldn't really know about each other in MVVM. They typically communicate via a messenger type service so there is a complete disconnect. If the parent view is going to hold a reference to the child view, you can just use the views INPC implementation (since have it already).

Kevin Marois21-Oct-11 12:14

21-Oct-11 12:14

Well, in summary, what I'm hoping to do is get some kind of notification in the parent ViewModel that a property in the child ViewModel has changed.

What about binding? Any way to do this?

Everything makes sense in someone's mind

SledgeHammer0121-Oct-11 12:41

21-Oct-11 12:41

How are you creating the child views? In my apps, I never create the VM directly, I just load the window.xaml and that uses a view locator service to instantiate the VM and wire it up.

Another question is how many properties are going to be changing and how often. If we are talking about 2 or 3 properties that will change 2 or 3 times then my answer would be different then if 50 properties were changing 1000s of times.

With the low prop count / low change count, you can use messenger as I mentioned below.

Also, do you care what property is changing? Or do you just want to know that the view is dirty? etc?

If the parent needs to know whenever 1 of 50 properties change and its new value, etc. I'd probably just have the child view use messenger to send open / close messages so the parent can sub to the INPC events in the child using weak events or something like that.

Again, all depends on how much you need to know about the property that changed and how often they are changing, but I threw out a bunch of options for you Smile | :)