So I have a datagrid that I need to add custom sorting for and I also need to know the exact order of the sort.
I have read in order to do this I need to implement a custom icollectionview and bind it to the datagrid.
The problem I am having is that the documentation Microsoft gives on this interface is not that great. Does anyone know how to do this or have any good tutorials on how to implement this interface for silverlight?
I'm looking for the same, and found this article from Colin Eberhardt. It shows how to implement sorting using an implementation of ICollectionView
If you figure out how to implement filtering, please let me know.
Silverlight 3 now supports and implementation of the ICollectionView, called PagedCollectionView.
This provides sorting and grouping, but not filtering.
The best example I've found is Microsoft's ICollectionView implementation that was created for use with the DataGrid. Unfortunately, they tagged it internal so you can't just use it outright (and a copy & paste of the source requires a few modifications). Bust out Reflector and open System.Windows.Controls.Data.dll - navigate to the System.Windows.Controls namespace and there you can find ListCollectionView. Here's the definition to show that it implements ICollectionView:
internal class ListCollectionView : ICollectionView, INotifyCollectionChanged, INotifyPropertyChanged, IEnumerable
...
I really wish MS would provide this class - practically every LOB app needs it.
Here's how you perform a sort using ICollectionView.
ICollectionView view = CollectionViewSource.GetDefaultView(someCollection);
view.SortDescriptions.Add(new SortDescription("someProperty", ListSortDirection.Ascending));
view.SortDescriptions.Add(new SortDescription("someOtherProperty", ListSortDirection.Descending));
However it's not exactly what I would call "custom sorting"... It just lets you choose the sort criteria and direction. Could you be more specific on what you want to do ?
For other's who browse to this question, I've found these sites helpful as well:
Silverlight 3 Custom Sorting with Paging Support - Manish Dalal's blog
ICollectionView explained « C# Disciples
I hope that Silverlight 5 has a better alternative. :)
Related
I need your opinion about UI and Databinding in WPF.
I had argue with my supervisor about UI & databinding. There is A class, it has ObservableCollection of B class, and B class also has ObservableCollection of C class. These classes are used while communicating with NI CAN and LIN device(it is not case).
On the other hand, in user interface there are bunches of TreeView and DataGrids. There are several instances of A class which is used to store data from devices and files, and they are binded to Treeview and Datagrids. But, he disagrees with this, and says to make separate other list of variables for TreeView and Datagrid to data binding. As he says UI data and other must be separate and I agree with it. But, in this case there are several lists of lists of lists and for example: copy from one list to other list when there is change on data takes much time and calculation ( -> UI element ). And other problems also.
I need your your opinion or other advice to come out better solution.
Thank you!!
It sounds like you are a student and doing this work as part of your studies. Either way, there is something to learn here.
Why not implement both approaches and see how they differ, and which you prefer? As it stands your question does not provide enough information for anyone else to tell you, and there is no way to short cut this kind of learning in my experience.
How do I fill a dictionary with sampledata to use in design mode?
I added xmlns:k="clr-namespace:System.Collections.Generic;assembly=mscorlib" to be able to add key-value pairs but somehow it still doesnt work.
Can someone help me with this please?
There is currently no proper support for generic class in XAML (in XAML 2009 there is x:TypeArguments, currently only usable in uncompiled XAML), a workaround is using custom markup extensions that create them via reflection. An example can be found in another answer of mine, you could adjust it for dictionaries so you can also add the key value pairs.
I'm fairly new to WP7 and totally new to Expression Blend.
I have a ListBox bound to a List of custom objects,
List<Person>
Each item in the list contains a custom control, MyControl which is bound to Person.
MyControl contains a TextBox which is bound to the Username property of Person.
All of this works fine. My question is: how do I set a default value for the TextBlock so that it becomes visible in the Designer or ExpressionBlend? With it being data bound, it has no text till it runs ... so I can't actually do any fancy styling using these wonderful tools unless I repeatedly delete the binding code to replace it with a string, make the changes, replace the binding code, repeat. Seems long winded!
Thanks,
Steven
What you want is "Design time data".
There are a number of ways of doing this. Fortunately there are also lots of resources online which explain it.
#Steven Have you looked at creating sample data in Blend to do what you require and then some binding to actually attached the data to the control bound to your list? You might like to check out Blend Sample Data as it guides you through a simple example of doing just that. You might then be able to adapt to to your own ends.
It depends if you are using any MVVM model or not.
My suggestion, if you are not using a MVVM, is to use Blend Sample data, is fast and quick.
If you are MVVM Light I've found very usefull to create two files:
DataService.cs - contains the real connection and data
DesignDataService.cs - contains the sample data
The two libraries are identical, from an call perspective so that in the ViewModelLocator you can swap them:
if (ViewModelBase.IsInDesignModeStatic)
{
SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();
}
else
{
//SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();
SimpleIoc.Default.Register<IDataService, DataService>();
}
In the Design class I've decided to create an XML file for each Model so that it's easy to change the sample data and test all possible scenarios.
I then use the Deserialize function to read it:
csNodeList _Copyrights = new csNodeList();
resource = System.Windows.Application.GetResourceStream(new Uri(#"Design/sampledata.xml", UriKind.Relative));
streamReader = new StreamReader(resource.Stream);
serializer = new XmlSerializer(typeof(csNodeList));
_Copyrights = (csNodeList)serializer.Deserialize(streamReader);
Please note that the file sampledata.xml has to be stored in folder Design and must be defined as Content not as Resource.
It is suggested to improve performance and load time.
M
I'm using the datacontextproxy class defined by Dan Wahlin to solve what seemed so very difficult for the many many hours leading up to that discovery.
I have a combobox that is bound to an ObservableCollection<Accounts>. The combobox also has the values: DisplayMemberPath=AccountNumber, and the SelectedValue={Binding SelectedAccount}. I then have a DataForm that has its CurrentItem property also bound to SelectedAccount. Inside my DataForm, I have a handful of fields that require additional dropdowns (AcctCode, UsageCode, etc). To mitigate the binding issues I ran into inside of a DataForm, I implemented the datacontextproxy, allowing me to set the ItemsSource of my cbobox to {Binding Source={StaticResource DataContextProxy}, Path=DataSource.AccountCodes}". This is working great in terms of the end result.
Before stumbling onto this, I really struggled with this find. I'm not using a domaincontext, so I couldn't use Kyle Mcllelans ComboBoxex, nor could I use the vast majority of solutions offered. I did try to create an instance of my ViewModel as a local resource in my View, but a) I felt dirty in terms of MVVM, and b) It failed to create a new VM instance, as my VM requires a number of service references to be passed in on construct.
In any case, I'm simply wondering if there's a way I should be doing this that's either more performant, more MVVM, more maintainable, more bestest'er, etc etc.
Thanks,
Scott
Scott I also have settled on using the DataContextProxy. I think use of it still provides a good MVVM solution where the view only has knowledge of the VM via binding or commanding.
I see use of it as a temporary solution until Silverlight 5 ships. In Silverlight 5 ancestor binding is introduced which will provide more flexibility in data binding.
Everyone raves about BindingList in place of DataTable.
How do you guys overcome the problem of column flexibility? For BindingList I need to define and implement T object. If any new columns needed to be added, I need to add new properties to T object....while in DataTable this is much easier.
BindingList<T> samples = new BindingList<T>();
Is that something you live with or is there a relatively easy way to overcome thing?
using c# 2.0, compact framework.
There are still (occasional) advantages to using DataTable - and having column flexibility is one of them. That being said, there are cons as well.
A small comparison of advantages and disadvantages to each are listed in this blog post.
My personal rule of thumb is to use BindingList<T> to bind to a collection of business objects. In this case, the column issue goes away (you know the columns that are useful in advance already), and it feels much more natural.
DataTable is still useful if you're binding to an unknown thing, and trying to do the parsing at runtime.