[RESOLVED] .Focus() Timing Issue

On the left half of my screen I have a datagridview. On the right half I have a document preview pane. As I change rows on the left half, I use the CurrentCellChanged event to open the document associated to that row in the previewer. This works fine, however, the focus is then placed in the preview pane which prevents the user from being able to use the arrow keys to step down a row at a time.

To combat this, I made the final event in my CurrentCellChanged routine set the focus back to my datagridview. Unfortunately, even this doesn’t always work because of what seems to be a timing issue. If the document to be previewed takes more than a fraction of a second to open, the code to move the focus to the datagridview is executed but after the image completes drawing, the focus is moved back to my previewer.

Any ideas? I don’t want to use a timer to force a delay and a DoEvents causes me some other issues. Is there some other event I can use to determine when my preview pane is complete and then and only then set the focus back to my datagrid?

What kind of control is the preview on the left side?

The previewer (on the right side) is actually multiple controls. One is a web browser for displaying pretty much everything that is NOT a word document. The other is a RichTextBox. If the document to be previewed is a word document, I extract the text and display it in the RTB.

I don't see how you you can lose focus from the DGV just by setting the text property of the RTB or call the Navigate method of you WB... Can you post the code in your DGV.CurrentCellChanged event handler?

Code:

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    Private Sub dgvDocuments_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles dgvAllDocuments.CurrentCellChanged
        If chkImageView.Checked Then
            FillDocPreview()
            dgvAllDocuments.Focus()
        End If
    End Sub

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Code:

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Private Sub FillDocPreview()

        If chkImageView.Checked AndAlso Not dgvAllDocuments.CurrentCell Is Nothing Then
            Dim previewPath As String = dgvAllDocuments.Item("FileName", dgvAllDocuments.CurrentRow.Index).Value.ToString
            Dim fullPath As String
            Dim displayIn As String
            Dim extension As String
            Dim tempTable As New DataTable

            fullPath = imageFileDirectory & "\" & previewPath


            extension = Path.GetExtension(fullPath)
            sql = "Select * from DocProfileFileTypes where FileType = '" & extension & "' "

            tempTable = da.GetDataTable(sql)

            If tempTable.Rows.Count > 0 Then
                displayIn = tempTable.Rows(0).Item("DisplayIn").ToString
            Else
                displayIn = String.Empty
            End If

            If displayIn = "Word" Then
                Dim appWord As New WordApp.Application
                Dim docWord As New WordApp.Document

                Try
                    If System.IO.File.Exists(imageFileDirectory & "\" & previewPath) Then
                        docWord = appWord.Documents.Open(imageFileDirectory & "\" & previewPath, [ReadOnly]:=True)

                        docWord.ActiveWindow.Selection.WholeStory()
                        docWord.ActiveWindow.Selection.Copy()

                        Dim data As IDataObject = Clipboard.GetDataObject()

                        rtbDocumentPreview.Text = CStr(data.GetData(DataFormats.StringFormat))
                    Else
                        rtbDocumentPreview.Text = "File not found."
                    End If

                Catch ex As Exception
                    Throw ex

                Finally
                    rtbDocumentPreview.Visible = True
                    appWord.Quit()
                    appWord = Nothing
                End Try

            ElseIf displayIn = "WebBrowser" Then
                If System.IO.File.Exists(imageFileDirectory & "\" & previewPath) Then
                    wbDocpreview.Navigate(imageFileDirectory & "\" & previewPath)
                    rtbDocumentPreview.Visible = False
                    wbDocpreview.Visible = True
                End If
            Else
                rtbDocumentPreview.Text = extension & " File type not supported in preview mode."
                rtbDocumentPreview.Visible = True
                wbDocpreview.Visible = False
            End If
        End If

        'Use do events to force the screen to redraw before returning the focus to the datagrid
        Application.DoEvents()
        'dgvAllDocuments.Focus()

    End Sub

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replace this line

Quote:

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dgvAllDocuments.Focus()

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with as below

vb Code:

With Me.DataGridView1
            .SelectionMode = DataGridViewSelectionMode.CellSelect
            .CurrentRow.Cells(0).Selected = True
            'it should be noted that mouse should not be clicked on any
            'control & also no other code should execute to set the focus 
            'on other controls , i mean like above
        End With

So you lost focus from the DVG only when the WB is used for preview, only when the RTB is used or both? I'm trying to narrow down what is stealing the focus... If it's the WB then you can handle the WB.DocumentCompleted event and send focus back to your DGV. Don't call the Focus method directly. Call the DGV.Select method instead.

Sorry, should have been more clear. It's only when I use the browser.

I'll try your suggestion.

Quote:

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Originally Posted by stanav

Don't call the Focus method directly. Call the DGV.Select method instead.

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Thanks Stanav, this worked perfectly.