[RESOLVED] Event Handler Error

[visualise01]

I get this error on my form, not sure what to do:

Error 1 Option Strict On does not allow narrowing in implicit type conversions between method 'Private Sub searchResult_SearchFileMatches(sender As Object, e As Jam.Shell.FileMatchEventArgs)' and delegate 'Delegate Sub EventHandler(sender As Object, e As System.EventArgs)'.

on RED Text

  Private ReadOnly Property FileMatchEventHandler() As EventHandler
        Get
            If (FileMatchEventHandler Is Nothing) Then
                FileMatchEventHandler = AddressOf searchResult_SearchFileMatches
            End If
            Return FileMatchEventHandler
        End Get
    End Property

[kleinma]

Use the generic EventHandler type

    Private ReadOnly Property FileMatchEventHandler() As EventHandler(Of Jam.Shell.FileMatchEventArgs)
        Get
            If (FileMatchEventHandler Is Nothing) Then
                FileMatchEventHandler = AddressOf searchResult_SearchFileMatches
            End If
            Return FileMatchEventHandler
        End Get
    End Property

[visualise01]

I have another error:-

Not sure what to do?

Error 1 'Public Event SearchFileMatches(sender As Object, e As Jam.Shell.FileMatchEventArgs)' is an event, and cannot be called directly. Use a 'RaiseEvent' statement to raise an event.

Error 1

 Private Sub searchResults_SearchCompleted(ByVal sender As System.Object, ByVal e As Jam.Shell.SearchCompletedEventArgs) Handles searchResults.SearchCompleted
        'remove the filematching eventhandler if specified, see buttStartSearch_Click
        searchResults.SearchFileMatches -= FileMatchEventHandler

        buttStopSearch.Enabled = False
        buttStartSearch.Enabled = True

        'reset the progress indicator
        SearchProgressBar.Visible = False
        SearchProgressBar.Value = 0

        'allow sorting again
        searchResults.HeaderStyle = ColumnHeaderStyle.Clickable

        'the search was cancelled by the user
        If e.Cancelled Then
            toolStripStatusLabel1.Text = "The search operation was cancelled by the user."
            Exit Sub
        End If

        'an error/exception occurred during the search, inform the user
        If e.[Error] IsNot Nothing Then
            Dim errString As String = "An Error occurred: " & e.[Error].Message
            MessageBox.Show(errString, "Search error", MessageBoxButtons.OK, MessageBoxIcon.Information)
            toolStripStatusLabel1.Text = errString
        Else
            'all went ok, the search is complete
            toolStripStatusLabel1.Text = "The search operation completed."
        End If
    End Sub

[kleinma]

VB does not support C# style +=/-= syntax for event wireup. You should use AddHandler and RemoveHandler to add and remove event handlers.

[jmcilhinney]

Are you switching to VB from C# by any chance? It looks like you're trying to use C# syntax in VB. You use AddHandler and RemoveHandler to add and remove event handlers in VB, e.g.

RemoveHandler searchResults.SearchFileMatches, AddressOf FileMatchEventHandler

Of course, the event handler would have to have been added using AddHandler in the first place.

[visualise01]

Yes, I converted the code from c#.

I have this code at the start:-

 Private m_fileMatchEventHandler As EventHandler(Of FileMatchEventArgs)

    ''' <summary>
    ''' provide on-access to our selfdefined file matching handler that extends the
    ''' search filter.
    ''' </summary>
    Private ReadOnly Property FileMatchEventHandler() As EventHandler(Of FileMatchEventArgs)
        Get
            If m_fileMatchEventHandler Is Nothing Then
                m_fileMatchEventHandler = New EventHandler(Of FileMatchEventArgs)(AddressOf searchResults_SearchFileMatches)
            End If
            Return m_fileMatchEventHandler
        End Get
    End Property

[jmcilhinney]

I don't understand why you have a property returning an event handler. What is the purpose of that?

[visualise01]

Thanks for your help, managed to get it working with:

RemoveHandler searchResults.SearchFileMatches, FileMatchEventHandler