In Silverlight, I've got a hyperlinkbutton defined as the following:
<HyperlinkButton Content="{Binding FileName}" NavigateUri="{Binding MailLogAttachmentID, StringFormat=\/DownloadFile.aspx?objecttype\=proposalattachment&id\=\{0\}}" />
When I try to view the designer, instead of the XAML, I get a Unhandled Exception has occurred error (Index (zero based) must be greater than or equal to zero and less than the size of the argument list) and it gives me the option of reloading the designer. This also breaks any intellisense while developing in XAML. If I remove the NavigateUri StringFormat expression, all is well. The application compiles fine and the hyperlink button works as expected.
Is there another way I can get this functionality without breaking the designer?
This should do the trick, if you don't want a complicated escaped expression:
<HyperlinkButton DataContext="{StaticResource s}" Content="{Binding FileName}">
<HyperlinkButton.NavigateUri>
<Binding Path="MailLogAttachmentID"
StringFormat="/DownloadFile.aspx?objecttype=proposalattachment&id={0}" />
</HyperlinkButton.NavigateUri>
</HyperlinkButton>
In any case, the character that was generating the exception was the ampersand, so if you write it like this, it should work too:
<HyperlinkButton Content="{Binding FileName}"
NavigateUri="{Binding MailLogAttachmentID, StringFormat=/DownloadFile.aspx?objecttype\=proposalattachment&id\={0}}" />
Related
From a control in a WPF XAML view, I need to access the properties of another control that I can reach in the Visual Tree only when walking up to a common parent control and then down from there.
As an example:
<PageUserControl>
<Grid>
<TextBlock Text="Some example text" />
</Grid>
<TextBlock Text="{Binding Source={RelativeSource Mode=FindAncestor, AncestorType=PageUserControl, Path=??? I want to access the TextBlock}" />
</PageUserControl>
I want to access the text property of the first text block from the second text block (this is just an example).
What I would need is a way to combine relative sources, first one to go up the visual tree and find the PageUserControl, second one to go down the visual tree from there and find the grid and then finally a third one to find the text block within the grid.
Am I missing something here or is it just not possible?
I cannot add control IDs or something like this, it has to work with control types only.
I was thinking about something like a relative source that takes a XPath syntax, but it seems as if this was meant for another purpose (binding XML documents).
Maybe another idea?
Thank you!
I found a solution for my problem. It is possible using this approach:
<PageUserControl>
<Grid>
<TextBlock Text="Some example text" />
</Grid>
<TextBlock Text="{Binding Path=Children[0].Children[0].Text,
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=PageUserControl}}" />
</PageUserControl>
While not very flexible, it is good enough for me.
This is something that has bothered me for some time, and I'm not sure if it's some setting that can be turned off or not, but whenever I copy and paste something in xaml in VS 2010 it always auto-indents the line that I'm on and often the one after it for some reason. For example, say I have these lines of xaml code:
<TextBlock VerticalAlignment="Top" Foreground="Red" FontSize="11" Width="5"
Text="*" Visibility="{Binding Path=ShowInvalidFlag,UpdateSourceTrigger=PropertyChanged}" />
<TextBlock Width="Auto" Background="Transparent" Text="{Binding Path=QuestionValue}" />
and then I realize that the first TextBlock needs a Margin defined and I copy Margin="0,1,0,0" from another control within the same xaml document and paste it within the declaration of the above TextBlock it auto-indents and I end up with this:
<TextBlock VerticalAlignment="Top" Margin="0,1,0,0" Foreground="Red" FontSize="11" Width="5"
Text="*" Visibility="{Binding Path=ShowInvalidFlag,UpdateSourceTrigger=PropertyChanged}" />
<TextBlock Width="Auto" Background="Transparent" Text="{Binding Path=QuestionValue}" />
Why is it doing this? It doesn't even have to be copied from the same xaml file or even xaml code (I just tried copying random text from a text file and pasted it within the control and it still auto-indented). It's quite frustrating that every time I paste something in xaml I need to re-adjust my indentation.
Converted from comment:
If you search in the options in VS you should be able to find under Text Editor and Xaml an option for Indenting. By default it's set to "smart" which isn't always as smart as you might want it to be. Play around with that and see if it's more comfortable for you. Copy / pasting seems to be particularly prone to tripping it up.
In addition, you can also always so to "Edit" -> "Advanced" and then either "Format Document" or "Format Selection" to force Visual Studio to take another pass at formatting which may either fix, or make worse, your problem.
I think the problem is that it tries to optimize between speed and correctness. When you paste something it may not consider the entire context of where you are pasting and instead only look at the immediate parent and / or siblings which is a problem when you are pasting in a whole bunch of stuff.
I have a nullable field in the database, called Generation. It specifies things like "Jr.", "II" and so on. I want a mean of conditionally specifying the generation of the client, if it isn't null, otherwise not displaying it at all. I thought that the following would work:
<TextBlock Text="{Binding LastName}" />
<TextBlock Text="{Binding Generation, StringFormat= {0}}" />
<TextBlock Text=", " />
However I'm getting an error saying that "0 is not supported in a Windows Presentation Foundation (WPF) project". The field value Generation is a varchar field. Can I do what I want with the StringFormat attribute of the TextBlock class, or do I need to use a converter?
You need to write this as:
<TextBlock Text="{Binding Generation, StringFormat={}{0}}" />
This is due to the nature of using the Markup Extension, which gives special meaning to {}. By adding this at the beginning (when you have no text before your first format specifier), it has the effect of "escaping" the string format specification for you, similar to how # is used to handle string literals in C#.
maybe you could help me understand why I get an unhandled exception "Invalid XAML" in Visual Studio 2010 designer when trying to do the following on a Page.
I have a Converter named DateTimeConverter that converts a date into a German date string. The converter works fine. I've included the namespace and added the following to the page's resources:
<navigation:Page.Resources>
<myClasses:DateTimeConverter x:Key="dateTime" />
</navigation:Page.Resources>
Now I have a list box that I want to bind to a list of objects. I do the binding in code, but I would like to define the data template. Thus I've added the following to my layout:
<ListBox x:Name="lbConversation" BorderBrush="#00000000">
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderThickness="0" Padding="4">
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Message, Mode=OneWay}" />
<TextBlock Text="{Binding TimeStamp, Mode=OneWay, Converter={StaticResource dateTime}}" />
</StackPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And this works fine when I run. However, in the code section, the code for the data template is undercurled and the designer says "Invalid XAML". When I remove the Converter=... part, this error is gone.
Is this a designer bug? What can I do?
EDIT
By the way: The exact same code does not throw the error within a WPF project!
Just adding to this question as I found a solution.
The solution to my case was here: http://forums.silverlight.net/post/618518.aspx
Apparently you must not have a space character in your project name or assembly name. D'oh!
Hope it helps.
Sorry, can't replicate this at all, do you have some design-time data that may be the cause of the weird error?
Also, since you said that you're using the converter to output german dates... wouldn't it be easier to let the framework do this kind of things, as it probably does them a lot better? Set the entire application thread's CultureInfo to german and all formatting will be done with that culture's settings; of course it's still possible you only want some controls internationalized...
I can't see anything wrong with your Xaml however I wonder if this is a result of the language setting used when the Xaml is parsed. By default Xaml is parsed using the InvariantCulture however it would appear that the designer in visual studio parses the Xaml using the current culture. Hence at times you can get unexpected differences in behaviour at design time than you do at runtime.
In fact if you do this in the constructor of your UserControl before calling InitializeComponent:-
this.Language = XmlLanguage.GetLanguage(Thread.CurrentThread.CurrentCulture.Name);
You might not need your converter at all.
I came across "Invalid XAML" error when I had my converter marked internal. Change the modifier to public and everything is as expected.
Hope this help.
I'd like an advice to the following problem: I want to embed a Button into a text flow, but when I embed a Button and Label (or TextBlock) into the WrapPanel, I get the first figure:
alt text http://sklad.tomaskafka.com/files/wpf-wrappanel-problem.png
I think that one of solutions could be FlowDocument, but I feel that this is far too heavy for a control simple like this (which could be used in several hundred instances). Do you have some other ideas about how to implement this? Thank you!
EDIT:
One solution could be the following (I didn't know it was possible to put more stuff into TextBlock), but I would lose the ability to bind (which I need):
<TextBlock TextWrapping="Wrap">
<Span>
<Button x:Name="MyButton" Command="{Binding Path=MyCommand}" Content="+" />
<Run x:Name="MyLabel" Text="{Binding Path=Subject}" />
<!--
Problem: binding makes following error:
A 'Binding' cannot be set on the 'Text' property of type 'Run'.
A 'Binding' can only be set on a DependencyProperty of a DependencyObject.
-->
</Span>
</TextBlock>
To bind to Run.Text, checkout the BindableRun class by Fortes. Simple to implement, I use it all over my projects.
I found that implementing BindableRun correctly is pretty tricky - and almost all other available implementations will cause an exception from wpf layouting engine when the bound content changes from null to something non-null - see this problem, keyword "Collection was modified; enumeration operation may not execute."
Corrrect implementation from Microsoft is here - it shows how tricky this really is.
Solution: BindableRun class + the following markup:
<TextBlock>
<Button x:Name="MyButton" Command="{Binding Path=MyCommand}" Content="+" />
<common:BindableRun x:Name="Subject" BindableText="{Binding Path=Subject}"/>
</TextBlock>
Funny thing it works on the designer of a UserControl...
In that case, using the Property Change of your control to set the value to the Run is enough. I mean, if you had something like:
<TextBlock>
<Run Text="{Binding ElementName=thisCtrl, Path=Description}" />
</TextBlock>
Then just name the run, and on your property change handler of your UserControl DependencyProperty get/set the value.