IParametersInProvider.NoParametersIn Event

NOTE: This API is now obsolete.

Occurs when there is no parameter list available to be sent to the consumer Web Part.

Namespace:  Microsoft.SharePoint.WebPartPages.Communication
Assembly:  Microsoft.SharePoint (in Microsoft.SharePoint.dll)

Syntax

'Declaration
<ObsoleteAttribute("Use System.Web.UI.WebControls.WebParts.IWebPartParameters instead")> _
Event NoParametersIn As NoParametersInEventHandler
'Usage
Dim instance As IParametersInProvider
Dim handler As NoParametersInEventHandler

AddHandler instance.NoParametersIn, handler
[ObsoleteAttribute("Use System.Web.UI.WebControls.WebParts.IWebPartParameters instead")]
event NoParametersInEventHandler NoParametersIn

Remarks

A Web Part that implements the IParametersInProvider interface should always raise either the ParametersInReady or the NoParametersIn event. Some Web Parts may not behave properly if they do not receive this information. Raise the ParametersInReady event to send the parameters. Raise the NoParametersIn event to indicate that there is no change in the parameters.

Examples

The following code example shows an overridden PartCommunicationMain method that fires the NoParametersIn event. This code example is part of a larger example provided for the IParametersInProvider interface.

      Public Overrides Sub PartCommunicationMain()
            ' Ensure that all of the Web Part's controls are created.
            EnsureChildControls()

            'Check if connected
            If _connected Then
                ' Create the ParametersInReadyEventArgs object for the ParametersInReady event.
                Dim parametersInReadyEventArgs As New ParametersInReadyEventArgs()

                If _parametersReadyButtonClicked Then 'ParametersInReady Button was clicked

                    ' Set the parameter values to the text box values.
                    If Not (_fieldList Is Nothing) Then
                        parametersInReadyEventArgs.ParameterValues = New String(_fieldList.Length) {}

                        Dim index As Integer
                        For index = 0 To _fieldList.Length - 1
                            parametersInReadyEventArgs.ParameterValues(index) = _fontAttributeTextBox(index).Text
                        Next index

                        ' Fire the ParametersInReady event.
                        RaiseEvent ParametersInReady(Me, parametersInReadyEventArgs)
                        '_fieldList is null
                    Else
                        ' Fire the event.
                        RaiseEvent NoParametersIn(Me, New EventArgs())
                    End If
                    _parametersReadyButtonClicked = False
                ElseIf _noParametersInButtonClicked Then 'NoParametersIn Button was clicked                       
                    ' Fire the NoParametersIn event.
                    RaiseEvent NoParametersIn(Me, New EventArgs())
                    _noParametersInButtonClicked = False
                End If
            End If
        End Sub
// Step #7: Implement 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 ParametersInReady or the 
// NoParametersIn event. Some parts
// may not behave properly if they are left waiting for this 
// information.
// ParametersInReady should be fired to send the parameters.
// NoParametersIn should be fired to indicate that there is no change 
// in the parameters.
public override void PartCommunicationMain()
{
    // Ensure that all of the Web Part's controls are created.
    EnsureChildControls();

    //Check if connected
    if(_connected)
    {
        // If there is a listener, fire the ParametersInReady event.
        if(ParametersInReady != null)
        {
            // Create the ParametersInReadyEventArgs object for the ParametersInReady event.
            ParametersInReadyEventArgs parametersInReadyEventArgs = new ParametersInReadyEventArgs();

            if(_parametersReadyButtonClicked) //ParametersInReady Button was clicked
            {
                // If there is a listener, fire the ParametersInReady 
                // event.
                if(ParametersInReady != null)
                {
                    // Set the parameter values to the text box values.
                    if (_fieldList != null)
                    {
                        parametersInReadyEventArgs.ParameterValues = new string[_fieldList.Length];

                        for (int index = 0; index < _fieldList.Length; index++)
                        {
                            parametersInReadyEventArgs.ParameterValues[index] = _fontAttributeTextBox[index].Text;
                        }

                        // Fire the ParametersInReady event.
                        ParametersInReady(this, parametersInReadyEventArgs);
                    }
                    else //_fieldList is null
                    {
                        // If there is a listener, fire the NoParametersIn event.
                        if(NoParametersIn != null)
                        {
                            // Fire the event.
                            NoParametersIn(this, new EventArgs());
                        }
                    }
                    _parametersReadyButtonClicked = false;
                }
            }
            else if(_noParametersInButtonClicked) //NoParametersIn Button was clicked
            {
                // If there is a listener, fire the NoParametersIn 
                // event.
                if(NoParametersIn != null)
                {
                    // Fire the NoParametersIn event.
                    NoParametersIn(this, new EventArgs());

                    _noParametersInButtonClicked = false;
                }
            }
        }
    }
}

See Also

Reference

IParametersInProvider Interface

IParametersInProvider Members

Microsoft.SharePoint.WebPartPages.Communication Namespace