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Basically, you need to handle IEditableCollectionView. When you click your checkbox, you'll start off by triggering the AddNew method where you'll add a new instance to the underlying collection; as this is databound you will update the UI automatically (you'll need to supply an add/edit datatemplate). If the user is happy with the data they entered, your code calls CommitNew; if they are unhappy, your code calls CancelNew (where the item is removed from the ObservableCollection). And that's it - you've just added the functionality you need to add/edit objects.
I have a post here[^] (it's WPF, but you should be able to easily adapt it to Silverlight) that covers how to do this with a sample set of classes to make things easier for you.
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Hi Pete O'Hanlon,
Thanks for the answer, but since I am very newbie to WPF and MVVM I did not get your point. Basically what I want is
1) Where to call Checkbox click event (View model or code behind) to populate detail grid collection.
2) Show detail grid only when checkbox is checked.
3) Retrieve values from detail and parent grid
Please let me know how I can achieve these from the code you mentioned above.
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You can bind to the IsChecked on the checkbox and trigger this from the VM. You don't retrieve values from the grid - remember that in MVVM, this information just comes from the data model - use that as your datasource.
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Thanks, that will solve #3 above but still not cleared on 1 and #2, specially how I handle checkbox event from viewmodel.
can you please some sample code if you have.
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You have answered your own question, #1 the event must be handled in the VM so bind the checked event to the vm and deal with it there.
As to the child datagrid I've not used this type of structure but with a tree view I have an observablecollection as a property of my main data source and populate that. Then you need an itemssource for each data row bound to the child collection.
I would consider the telerik treeview as it has the columns as well as the tree structure.
Never underestimate the power of human stupidity
RAH
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Mycroft gave you the answer. Effectively, you'll have a checked property in the the VM which you'll bind to from your checkbox. That will be the trigger for the update - although, to be honest, I don't think that using a checkbox to kick off the behaviour you want is the best way forward.
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thanks for tips, I am now successfully able to bind the BlogIsSelected property to the grid checkbox column. but I am not able to acheive following with the code below
1) Show detail grid only when it checkbox is selected
2) attach event to checkbox column, I did not find any click event for this column
Can you please correct the xaml I am using
Thanks
Ankur bhargava
<DataGrid x:Name="FamilyEditorGrid" ItemsSource="{Binding Path=AllBlogs}" MaxHeight="575"
Background="{x:Null}"
Margin="0,0,0,0"
BorderBrush="{x:Null}"
AutoGenerateColumns="False"
SelectionMode="Single"
GridLinesVisibility="None"
RowDetailsTemplate="{StaticResource RowDetailItemTemplate}"
RowDetailsVisibilityMode="{Binding Path=BlogIsSelected, Converter={StaticResource boolToVisibilityConverter}}"
>
<DataGrid.CellStyle>
<Style TargetType="{x:Type DataGridCell}">
<Setter Property="VerticalContentAlignment" Value="Center" />
</Style>
</DataGrid.CellStyle>
<!--<DataGrid.RowStyle>
<Style TargetType="{x:Type DataGridRow}">
<Setter Property="Height" Value="32" />
</Style>
</DataGrid.RowStyle>-->
<DataGrid.Columns>
<DataGridCheckBoxColumn Header=""
Binding="{Binding Path=BlogIsSelected}"
SortMemberPath="BlogIsSelected" Width="35"
/>
<DataGridTextColumn Header="Blog URL"
Binding="{Binding BlogURL}"
SortMemberPath="BlogURL"
IsReadOnly="True" Width="auto" />
</DataGrid.Columns>
</DataGrid>
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Hello!
I wish to have an icon (Path) which scales forever until some background operation is finished. I managed to bind a DataTrigger to my dependency property InProgress. However, I want the animation to repeat so I bound RepeatBehavior to InProgress as well. Here I get an exception "'Set property 'System.Windows.FrameworkElement.Style' threw an exception.' Line number '241' and line position '22'.". The inner one is: "Cannot freeze this Storyboard timeline tree for use across threads."
<Path.Style>
<Style TargetType="Path">
<Style.Triggers>
<DataTrigger Binding="{Binding InProgress}" Value="True" >
<DataTrigger.EnterActions>
<BeginStoryboard>
<Storyboard AutoReverse="True"
RepeatBehavior="{Binding Path=InProgress, Converter={x:Static Converters:BooleanToRepeatBehaviourConverter.Instance}}" >
<DoubleAnimation To="0.125" Duration="0:0:0.12"
Storyboard.TargetProperty="(LayoutTransform).(ScaleTransform.ScaleX)" />
<DoubleAnimation To="0.125" Duration="0:0:0.12"
Storyboard.TargetProperty="(LayoutTransform).(ScaleTransform.ScaleY)" />
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
</DataTrigger>
</Style.Triggers>
</Style>
</Path.Style>
The exception started to occur after binding the RepeatBehavior. Before doing that, the animation displayed correctly but only once. Note that I have been using the InProgress property for binding before and it worked. The converter:
public class BooleanToRepeatBehaviourConverter : IValueConverter
{
private static readonly IValueConverter instance = new BooleanToRepeatBehaviourConverter();
public static IValueConverter Instance
{
get { return instance; }
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return (bool) value
? RepeatBehavior.Forever
: new RepeatBehavior(0);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
How to solve the problem?
Thanks in advance!
Greetings - Jacek
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Pete's answer:
Pete wrote: The issue is that resources that are in or consumed in a control template have to be frozen. This is done so that the resource can be shared across control instances quickly. Once you set the binding on the Dependency Object on a Freezable, you stop it from being frozen.
As you can't create a static resource of the RepeatBehavior, I'd suggest that this is one of those instances where it is perfectly legitimate to have code in the code behind of the view. Don't tie yourself into logical knots here - view specific code in the view code-behind is legitimate.
Greetings - Jacek
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Hi All,
I am a newbie in Silverlight. We are using WCF services and Stored Procs. I would like to implement custom pagination using Datapager(the look and feel) and WCF services. I would like to pull only the required rows from the db. Can this be achieved using just the WCF services and not the WCF RIA services?
I have browsed through the web and learned that it can be achieved in 2 ways
1. WCF RIA services, DomainServices, DomainDataSource
2. Custom Pagination using own controls and not using DataPager.
I dont want to use both of these approaches.
Kindly let me know if there is any other alternative to achieve this using the DataPager and WCF Services.
Thanks a Ton...
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I hate to supply a search for such a well placed question but there seems to be a number of solutions out there based on sql server data paging[^]
What you are describing is paging implemented at the database level rather than the DAL or UI layers. Caveat I have never used paging - ever so my experience is rather limited.
Never underestimate the power of human stupidity
RAH
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how i can set & get pixel of image in wpf application(C#)?
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I need to sort the items in autocompletebox. It has binding to an observable collection of strings.
With a combobox I used the Items.SortDescriptions but this does not work for the ACB.
I tried the following but cant find the listbox property name
//lst = acb1.Template.FindName("SelectionAdapter", acb1) as ListBox;
// if (lst != null)
// lst.Items.SortDescriptions.Add(sd);
So what is the best way to do it please?
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Moonwalker031 wrote: It has binding to an observable collection of strings.
Sort the observablecollection before binding.
Never underestimate the power of human stupidity
RAH
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Well I tried myobscol.orderby(x=>x) but did not work.
I am adding and removing items from the list during execution so would like an automatic sort instead of sorting manually each time.
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You are manipulating the list "manually" when you insert/remove items, why can't you sort it then.
Do some research on sorting observablecollections.
Never underestimate the power of human stupidity
RAH
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Ok solved.
When I searched for sorting Observable collection I read that I had to create another copy of the list which I was trying to avoid.
I inserted the line below after adding items to the list. This should not create unnecessary lists.
acb1.ItemsSource = myobscol.OrderBy(x => x);
Back to the first post. What is the name of the Listbox property in the Autocomplete box? I still need this for somthing else.
ListBox lst = acb1.Template.FindName("SelectionAdapter", acb1) as ListBox;
This does not work and gives a null. I tried "ListBox" and "ItemContainerStyle" but still got a null.
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Rather than manipulating your ObservableCollection, take a look at using CollectionViewSource instead. This provides the ability to sort and filter collection items any which way you want.
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Thanks I came across the CollectionViewSource already. But since my project is almost complete and based on Observable collection I didn't want to change everything.
Anyway now the sorting is solved and working properly (see previous post).
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Hi,
In my application on clicking a link i m opening an aspx page in different IE window.Now I want to display "Loading..." on the parent IE window's status bar untill the new window opens when the link is clicked.
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Try HtmlPage.Window.SetProperty("defaultStatus", "Loading..."); .
However, note this is only for IE.
I'm not sure what you need to do for Firefox or other browsers.
The funniest thing about this particular signature is that by the time you realise it doesn't say anything it's too late to stop reading it.
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You are welcome. Vote or mark as answered if this answer helped though.
The funniest thing about this particular signature is that by the time you realise it doesn't say anything it's too late to stop reading it.
modified on Tuesday, March 15, 2011 8:05 AM
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