http://forums.lhotka.net/forums/thread/544.aspx
Hi,
I implemented sorting using the GridView control and the SortedBindingList as described in the above thread. It works great.
Now I need to bind a DetailsView control to a specific object in the collection when the user clicks "Edit" on a particular row. My code looks like this:
protected void CslaDataSource2_SelectObject(object sender, Csla.Web.SelectObjectArgs e)
{
//get the business object for the DetailsView
e.BusinessObject = GetSelectedEvent();
}
private Event GetSelectedEvent()
{
SortedBindingList<Event> evts = GetEvents(false);
if (grdEvents.SelectedValue != null)
{
int index = evts.Find("EvtID", (int)grdEvents.SelectedValue);
return evts[index];
}
return null;
}
I get a Specified method is not supported error inside SortedBindingList.cs. The line of code where the error happens is:
return _bindingList.Find(property, key);
Do I need to code a Find method in my EditableRootList class?
Thanks,
Mike
More info:
I was able to get the above error to stop happening by adding a FindCore procedure to my BusinessList class. Then I quickly realized that it was returning the index to my BusinessList, not the SortedBindingList. Which caused the wrong record to appear in the DetailsView.
So, to try an fix my problems, I'm now using a Session["currentSortObject"] and a Session["currentObject"]. One contains the SortedBindingList and the other contains the associated BusinessList. It's working properly from the user's perspective but it seems like a hack.
Has anyone posted example code of a fully functional, bound GridView/DetailView that's sortable and editable? I have the PTWeb example project but it's pretty basic.
Thanks,
Mike
Hi Mike,
I'm looking to sort the DetailsView at runtime but haven't found a way to do it. Did you ever find a solution to this problem?
Thanks,
Paul
Actually, I would like to implement the Find method into my business objects but think it will seat better into the CSLA Framework with help of generics like :
public GroupInfo Find(string[] propertyNames, object[] values)
{
if (propertyNames == null)
throw new Exception("No property name is defined.");
if (values == null)
throw new Exception("No values are defined.");
if (propertyNames.Length != values.Length)
throw new Exception("Number of values does not match count of property names.");
int propertyIndex= 0;
string propertyName = String.Empty;
List<PropertyDescriptor> properties = new List<PropertyDescriptor>();
PropertyDescriptorCollection propertyDescriptorCollection = TypeDescriptor.GetProperties(typeof(GroupInfo));
for (propertyIndex = 0; propertyIndex < propertyNames.Length; propertyIndex++)
{
propertyName = propertyNames[propertyIndex];
if(String.IsNullOrEmpty(propertyName))
throw new Exception("An empty or null string was provided as property name.");
try { properties.Add(propertyDescriptorCollection[propertyName]); }
catch { throw new Exception(String.Format("Property [{0}] does not exist in the object.", propertyName)); }
}
for (int itemIndex = 0; itemIndex < this.Count; itemIndex++)
{
bool itemMatch = true;
for (propertyIndex = 0; propertyIndex < properties.Count; propertyIndex++)
{
PropertyDescriptor propertyDescriptor = properties[propertyIndex];
object value = values[propertyIndex];
itemMatch = propertyDescriptor.GetValue(this[itemIndex]).Equals(value);
if (!itemMatch)
break;
}
if (itemMatch)
return this[itemIndex];
}
return null;
}
Regards
You could also view a find operation as a special case of a
filter operation. Then you could use FilteredBindingList to simply create a
view of your collection that only shows the matching items.
The problem with doing arbitrary Find operations (especially ones
that return n items) in a CSLA setting is that the objects you get back belong
to a collection. They are child objects, and thus aren’t designed to
stand alone out of context.
In some cases a Find makes sense, but in many cases you run the
risk of doing things to those objects that are illegal.
The FilteredBindingList approach avoids that issue, because the
objects are left in context. FilteredBindingList is merely a view over the original
list (just like SortedBindingList), and so you are automatically prevented from
doing illegal things to the objects, because they are still “in context”
within their parent collection.
Rocky
From: fmahieux
[mailto:cslanet@lhotka.net]
Sent: Tuesday, March 13, 2007 7:38 AM
To: rocky@lhotka.net
Subject: Re: [CSLA .NET] SortedBindingList.Find
Actually, I would like to implement the Find method into my business objects
but think it will seat better into the CSLA Framework with help of
generics like :
public GroupInfo
Find(string[] propertyNames, object[] values)
{
if (propertyNames == null)
throw new Exception("No
property name is defined.");
if (values == null)
throw new Exception("No
values are defined.");
if (propertyNames.Length != values.Length)
throw new Exception("Number
of values does not match count of property names.");
int propertyIndex= 0;
string propertyName = String.Empty;
List<PropertyDescriptor>
properties = new List<PropertyDescriptor>();
PropertyDescriptorCollection
propertyDescriptorCollection = TypeDescriptor.GetProperties(typeof(GroupInfo));
for (propertyIndex = 0; propertyIndex <
propertyNames.Length; propertyIndex++)
{
propertyName = propertyNames[propertyIndex];
if(String.IsNullOrEmpty(propertyName))
throw new Exception("An
empty or null string was provided as property name.");
try { properties.Add(propertyDescriptorCollection[propertyName]);
}
catch { throw new Exception(String.Format("Property [{0}] does not exist in the object.",
propertyName)); }
}
for (int
itemIndex = 0; itemIndex < this.Count;
itemIndex++)
{
bool itemMatch = true;
for (propertyIndex = 0; propertyIndex <
properties.Count; propertyIndex++)
{
PropertyDescriptor propertyDescriptor =
properties[propertyIndex];
object value = values[propertyIndex];
itemMatch = propertyDescriptor.GetValue(this[itemIndex]).Equals(value);
if (!itemMatch)
break;
}
if (itemMatch)
return this[itemIndex];
}
return null;
}
Regards
Hi,
I reactivate this thread because I am in the same situation with the error described in the first post.
I use the VB version CSLA 3.52 with VB 2008.
The error : Specified method is not supported.
occurs in SortedBindingList
''' <summary>
''' Implemented by IList source object.
''' </summary>
''' <param name="key">Key value for which to search.</param>
''' <param name="property">Property to search for the key
''' value.</param>
Public Function Find(ByVal [property] As System.ComponentModel.PropertyDescriptor, ByVal key As Object) As Integer Implements System.ComponentModel.IBindingList.Find
If _supportsBinding Then
Return SortedIndex(_bindingList.Find([property], key))
Else
Return -1
End If
End Function
in the line Return SortedIndex(_bindingList.Find([property], key))
What can I do to solve that issue ?
Another question about SortedBindingList :
A SortedBindingList is a view of an original list.
Is it possible to have directly only a list that we can sorted and bound to a datagridview without to have an original list ?
Thanks
Dominique
I found a solution with some searchs in Google at
http://www.eggheadcafe.com/software/aspnet/31881441/sorting-bindinglist-based.aspx
My original list was a BindingList :
Public Shared listRubSyst As New BindingList(Of htRubriExtension)
I create a subclass for BindingList :
Public Class BindingList2(Of T)
Inherits BindingList(Of T)
Protected Overloads Overrides ReadOnly Property SupportsSearchingCore() As Boolean
Get
Return True
End Get
End Property
Protected Overloads Overrides Function FindCore(ByVal prop As PropertyDescriptor, _
ByVal key As Object) As Integer
If prop Is Nothing Then
Throw New ArgumentNullException("prop")
End If
For i As Integer = 0 To Count - 1
Dim item As Object = Me(i)
If item IsNot Nothing AndAlso Object.Equals(key, prop.GetValue(item)) Then
Return i
End If
Next
Return -1
End Function
End Class
And now the original list is :
Public Shared listRubSyst As New BindingList2(Of htRubriExtension)
Now it is good. The error was in the BindingList.
I don't understand why Microsoft doesn't correct such errors since so many times.
dg78: