IFilterProvider.ClearFilter Event
NOTE: This API is now obsolete.
Notifies the consumer Web Part to clear the current filter.
Namespace: Microsoft.SharePoint.WebPartPages.Communication
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Syntax
'Declaration
<ObsoleteAttribute("Use System.Web.UI.WebControls.WebParts.IWebPartParameters instead")> _
Event ClearFilter As ClearFilterEventHandler
'Usage
Dim instance As IFilterProvider
Dim handler As ClearFilterEventHandler
AddHandler instance.ClearFilter, handler
[ObsoleteAttribute("Use System.Web.UI.WebControls.WebParts.IWebPartParameters instead")]
event ClearFilterEventHandler ClearFilter
Examples
The following code example shows an overridden PartCommunicationMainmethod that fires the ClearFilter event. This code example is part of a larger example provided for the IFilterProvider interface.
' Step #7: Override the PartCommunicationMain() method.
' The PartCommunicationMain method is called by the Web Part
' infrastucture on the client during the ASP.NET PreRender
' event to allow the part to pass its primary data to the other
' connected parts.
' It is important to always fire either the SetFilter, NoFilter,
' or ClearFilter event. Some parts
' may not behave properly if they are left waiting for this
' information.
' SetFilter should be fired to send the filter expression.
' NoFilter should be fired to indicate that there is no change in
' the filter expression.
' ClearFilter should be fired to indicate that the filter should
' be removed.
Public Overrides Sub PartCommunicationMain()
' Ensure that all of the Web Part's controls are created.
EnsureChildControls()
' Check if connected.
If _connected Then
' Check which button was clicked.
If _setFilterClicked = True Then
' Create the SetFilterEventArgs object for the
' SetFilter event.
Dim setFilterEventArgs As New SetFilterEventArgs()
' Create the filter expression.
Dim eIndex As Integer = 1
Dim filterExpression As String = String.Empty
Dim index As Integer
For index = 0 To _fieldList.Length - 1
' This filter expression syntax should be used
' with SharePoint Lists
' and other Microsoft Web Parts that support
' the IFilterConsumer interface.
If _filterInputs(index).Text <> String.Empty
Then
filterExpression += FieldLabel +
eIndex.ToString() + "=" +
_fieldList(index) + "&"
filterExpression += ValueLabel +
eIndex.ToString() + "=" +
_filterInputs(index).Text + "&"
eIndex += 1
End If
Next index
' Trim Off Trailing '&'
If filterExpression.Length <> 0 Then
filterExpression = filterExpression.Substring(0, filterExpression.Length - 1)
End If
' Set the FilterExpression property on the
' SetFilterEventArgs object.
setFilterEventArgs.FilterExpression =
filterExpression
' Set the _filterExpression variable for display in
' the user interface.
_filterExpression = filterExpression
' Fire the event.
RaiseEvent SetFilter(Me, setFilterEventArgs)
_setFilterClicked = False
ElseIf _clearFilterClicked = True Then
RaiseEvent ClearFilter(Me, New EventArgs())
_clearFilterClicked = False
' Clear out values in input text boxes.
If Not (_filterInputs Is Nothing) Then
Dim index As Integer
For index = 0 To _filterInputs.Length - 1
_filterInputs(index).Text = String.Empty
Next index
End If
ElseIf _noFilterClicked = True Then
RaiseEvent NoFilter(Me, New EventArgs())
_noFilterClicked = False
Else
RaiseEvent NoFilter(Me, New EventArgs())
End If
End If
End Sub
// Step #7: Override the PartCommunicationMain() method.
// The PartCommunicationMain method is called by the Web Part
// infrastructure on the client during the ASP.NET PreRender
// event to allow the part to pass its primary data to the other
// connected parts.
// It is important to always fire either the SetFilter, NoFilter, or
// ClearFilter event. Some parts
// may not behave properly if they are left waiting for this
// information.
// SetFilter should be fired to send the filter expression.
// NoFilter should be fired to indicate that there is no change in the
// filter expression.
// ClearFilter should be fired to indicate that the filter should be
// removed.
public override void PartCommunicationMain()
{
// Ensure that all of the Web Part's controls are created.
EnsureChildControls();
// Check if connected.
if(_connected)
{
// Check which button was clicked.
if(_setFilterClicked == true)
{
// If there is a listener, fire the SetFilter event.
if (SetFilter != null)
{
// Create the SetFilterEventArgs object for the
// SetFilter event.
SetFilterEventArgs setFilterEventArgs = new
SetFilterEventArgs();
// Create the filter expression.
int eIndex = 1;
string filterExpression = string.Empty;
for (int index = 0; index < _fieldList.Length; index++)
{
// This filter expression syntax should be used
// with SharePoint lists
// and other Microsoft Web Parts that support the
// IFilterConsumer interface.
if (_filterInputs[index].Text != string.Empty)
{
filterExpression += FieldLabel +
eIndex.ToString() + "=" +
_fieldList[index] + "&";
filterExpression += ValueLabel +
eIndex.ToString() + "=" +
_filterInputs[index].Text + "&";
eIndex++;
}
}
// Trim Off Trailing '&'
if (filterExpression.Length != 0)
filterExpression = filterExpression.Substring(0,filterExpression.Length - 1);
// Set the FilterExpression property on the
// SetFilterEventArgs object.
setFilterEventArgs.FilterExpression = filterExpression;
// Set the _filterExpression variable for display in
// the user interface.
_filterExpression = filterExpression;
// Fire the event.
SetFilter(this, setFilterEventArgs);
_setFilterClicked = false;
}
}
else if(_clearFilterClicked == true)
{
// If there is a listener, fire the ClearFilter event.
if (ClearFilter != null)
{
ClearFilter(this, new EventArgs());
_clearFilterClicked = false;
// Clear out values in input text boxes.
if (_filterInputs != null)
{
for (int index = 0; index < _filterInputs.Length;
index++)
_filterInputs[index].Text = string.Empty;
}
}
}
else if(_noFilterClicked == true)
{
// If there is a listener, fire the NoFilter event.
if (NoFilter != null)
{
NoFilter(this, new EventArgs());
_noFilterClicked = false;
}
}
else
{
// If there is a listner, fire the NoFilter event.
if (NoFilter != null)
{
NoFilter(this, new EventArgs());
}
}
}
}