In the collection class, I am overriding the OnInsertComplete method and
raising the ListChanged event, with proper args.
Although, the entire code was not required still I removed certain not
required methods and am posting the code. I have created custom objects for
holding the data and the fields are marked with custom attributes. Code goes
her.....
using System;
using System.Collections;
using System.ComponentModel;
using System.Runtime.Remoting;
namespace BusinessEntity
{
public abstract class BECollection : CollectionBase, ITypedList,
IBindingList
{
protected Type _containedType;
public BECollection( Type t )
{
this._containedType = t;
}
virtual internal int Add( BEBase obj )
{
return this.InnerList.Add(obj);
}
virtual internal void Remove( BEBase obj )
{
this.InnerList.Remove(obj);
}
public BEBase this[int index]
{
get
{
return InnerList[index];
}
set
{
List[index] = value;
}
}
PropertyDescriptorCollection ITypedList.GetItemProperties(
PropertyDescriptor[] listAccessors )
{
Type typeOfObject = null;
if( (listAccessors==null) || listAccessors.Length==0 )
{
typeOfObject = _containedType;
}
return this.GetPropertyDescriptors( typeOfObject );
}
string ITypedList.GetListName(PropertyDescriptor[] listAccessors)
{
return "Learning..";
}
private PropertyDescriptorCollection GetPropertyDescriptors( Type
typeOfObject )
{
PropertyDescriptorCollection typePropertiesCollection =
TypeDescriptor.GetProperties( typeOfObject );
ArrayList propertyDescriptorsToUse = new ArrayList();
foreach(PropertyDescriptor property in
typePropertiesCollection)
{
BEFieldAttribute befieldAttribute =
(BEFieldAttribute)property.Attributes[typeof(BEFieldAttribute)];
if (befieldAttribute != null)
{
// add it, as it has the attribute
applied to it
propertyDescriptorsToUse.Add(property);
}
}
return new
PropertyDescriptorCollection((PropertyDescriptor[])propertyDescriptorsToUse.ToArray(typeof(PropertyDescriptor)));
}
public void AddIndex(PropertyDescriptor property)
{
throw new NotSupportedException();
}
public bool AllowNew
{
get
{
return true;
}
}
public void ApplySort(PropertyDescriptor property,
System.ComponentModel.ListSortDirection direction)
{
throw new NotSupportedException();
}
public PropertyDescriptor SortProperty
{
get
{
throw new NotSupportedException();
}
}
public int Find(PropertyDescriptor property, object key)
{
throw new NotSupportedException();
}
public bool SupportsSorting
{
get
{
return false;
}
}
public bool IsSorted
{
get
{
throw new NotSupportedException();
}
}
public bool AllowRemove
{
get
{
return true;
}
}
public bool SupportsSearching
{
get
{
return false;
}
}
public System.ComponentModel.ListSortDirection SortDirection
{
get
{
throw new NotSupportedException();
}
}
public event System.ComponentModel.ListChangedEventHandler
ListChanged;
public bool SupportsChangeNotification
{
get
{
return true;
}
}
public void RemoveSort()
{
throw new NotSupportedException();
}
public object AddNew()
{
object obj =
Activator.CreateInstance(this._containedType);
BEBase be = (BEBase)obj;
List.Add(be);
return obj;
}
public bool AllowEdit
{
get
{
return true;
}
}
public void RemoveIndex(PropertyDescriptor property)
{
throw new NotSupportedException();
}
protected override void OnInsertComplete(int index, object value)
{
ListChanged(this, new
ListChangedEventArgs(ListChangedType.ItemAdded,
index));
}
}
}
Thanks
Regards,
Girish Jain
From: Frans Bouma <[EMAIL PROTECTED]>
Reply-To: "Discussion of advanced .NET topics."
<ADVANCED-DOTNET@DISCUSS.DEVELOP.COM>
To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM
Subject: Re: [ADVANCED-DOTNET] CurrencyManager and Data Binding
Date: Fri, 2 Jun 2006 12:31:14 +0200
> I have created a custom collection class which inherits from
> CollectionBase class and implements the IBindingList
> interface. I am having a problem regarding adding a new
> record and form binding. When I add a new record by calling
> the AddNew() method on the CurrencyManager class instance,
> the screen does not get refreshed. When I tried to figure out
> the problem, I found that the position of the CurrnecyManager
> does not change, and it does not fire the PositionChanged
> event. I figured that the
> CurrnecyManager.AddNew() method calls the
> IBindingList.AddNew() and it internally calls the
> ChangeRecordState() method. By looking at the call stack, I
> see that the newPosition argument passed to
> ChangeRecordState() method is correct and it raises the
> CurrentChanged event whereas the PositionChanged event does
> not get fired and the UI is not updated.
>
> When I move the record position by incrementing or
> decrementing the Positon property, the UI controls does get
> updated normally but not in the case of
> AddNew() i.e.
>
> _cm.Position = _cm.Count-1;
>
> also does not work
>
> Your inputs on this would be highly appreciated
You should raise ListChanged events in your class. You should pass
the index of the item changed/ added/ removed as well as
the type of the change in the eventargs.
Frans
===================================
This list is hosted by DevelopMentor® http://www.develop.com
View archives and manage your subscription(s) at http://discuss.develop.com
===================================
This list is hosted by DevelopMentor® http://www.develop.com
View archives and manage your subscription(s) at http://discuss.develop.com
