Without WPF, we will create the loop through all the items and will hide/show the items accordingly. But with WPF, we can do it very easily. I will explain in the following example.
Create a class SampleClass with Two Properties, Name(of string type) and Visible(of boolean type)
Create an ObservableCollection of type SampleClass in your Xaml.cs.
Code : ObservableCollection< SampleClass > collection = new ObservableCollection
Add few Items :
collection.Add(new SampleClass("Vikas", true));
collection.Add(new SampleClass("Sonia", true));
collection.Add(new SampleClass("Viman", False));
collection.Add(new SampleClass("Krishna", False));
Add the collection to our listview
myListView.DataContext = collection.
Now, for having a smooth access on filtering, sorting etc features, we will need to get the ICollectionView(Click to know more about ICollectionView) object out of out observable collection.
ICollectionView view = CollectionViewSource.GetDefaultView(collection);
now, to apply the filter we can use the following line anywhere in the code where in we want to put a filter on:
view.Filter = delegate(object item)
{
SampleClass sItem = item as SampleClass;
bool retValue = false;
if(sItem!=null)
{
retValue = sItem.Visible;
}
return retValue;
}
We can do the above step by using a new method with the predicate as well.
private bool GetVisibleState(object item)
{
SampleClass sItem = item as SampleClass;
bool retValue = false;
if(sItem!=null)
{
retValue = sItem.Visible;
}
return retValue;
}
And add the filter like following :
view.Filter = new Predicate< object >(GetVisibleState);
The above code will show the items in which the Visible property is set to true.
The code in VB.net is as follows :
Dim view As ICollectionView
Dim collection As ObservableCollection(Of SampleClass) = New ObservableCollection(Of SampleClass)
collection.Add(New SampleClass("Vikas", True))
collection.Add(New SampleClass("Sonia", True))
collection.Add(New SampleClass("Viman", False))
collection.Add(New SampleClass("Krishna", False))
myListView.DataContext = collection
view = CollectionViewSource.GetDefaultView(collection)
view.Filter = New Predicate(Of Object)(AddressOf FilterItems)
Private Function FilterItems(ByVal param As Object) As Boolean
Dim proxy As SampleClass
Dim Name As String
Dim retValue As Boolean
Name = combovalue ' (some arbit value, which you want to use as a filter. Example, the if you want to filter the value if the name is vikas, then say name = "Vikas")
proxy = TryCast(param, SampleClass)
retValue = proxy.Show
Return retValue
End Function
Public Class SampleClass
Private _name As String
Private _show As Boolean
Public Sub New(ByVal name As String, ByVal show As Boolean)
_name = name
_show = show
End Sub
Public Property Name() As String
Get
Return _name
End Get
Set(ByVal value As String)
_name = value
End Set
End Property
Public Property Show() As Boolean
Get
Return _show
End Get
Set(ByVal value As Boolean)
_show = value
End Set
End Property
End Class
