Cheers Mark (and everyone else). Several good ideas there. (Though I have to admit I rather like the OnPaint() suggestions from various people as a quick-and-easy fix).
Whatever happened to the OnInitialUpdate() of MFC? <g> Simon --------------------------------------------------------------- Simon Robinson http://www.SimonRobinson.com --------------------------------------------------------------- ----- Original Message ----- From: "Mark Boulter" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, May 24, 2002 4:02 PM Subject: Re: [DOTNET] Displaying info on loading forms As per previous posts the right way to do this to do the work on a background thread and signal completion to the UI thread. If you want to do this make sure to marshall your call back to the UI thread using Control.Invoke. The cheap and diryt way to do this is to async invoke in the Load event and then do you work in the invoked method. Assuming you have a form with a big "please wait" label plastered across it your code would look something like this: private void MainForm_Load(object sender, System.EventArgs e) { this.BeginInvoke(new MethodInvoker(this.DoWork)); } private void DoWork () { this.Cursor = Cursors.WaitCursor; Application.DoEvents(); try { Do lots of work } finally { this.Cursor = Cursors.Default; this.label1.Visible = false; } } This will get your form display before doing the work however while "do lots of work" is going on the form will not repaint if you move another window over it....... Using another thread would look something like: Public Delegate Sub UpdateUI(ByRef newDS As DataSet) 'Call Web Service asynchronously Private Sub LoadAuthors() Application.DoEvents() Me.Cursor = Cursors.WaitCursor Try StatusBar1.Text = "Loading..." Dim ws As New MyServices.AuthorInformationService() Dim callBack As New AsyncCallback(AddressOf LoadAuthorsComplete) ws.BeginListAuthors(callBack, 0) Catch ex1 As Exception MsgBox(ex1.ToString) StatusBar1.Text = "Error Loading author information" Me.Cursor = Cursors.Default End Try End Sub 'Call back from Web Service on non-UI thread Private Sub LoadAuthorsComplete(ByVal ar As IAsyncResult) Dim ds As DataSet Try Dim ws As New MyServices.AuthorInformationService() ds = ws.EndListAuthors(ar) Catch ex1 As Exception MsgBox(ex1.ToString) Throw ex1 End Try Dim updateUIDelegate As New UpdateUI(AddressOf Me.LoadAuthorsUpdateUI) Dim args As Object() = {ds} Me.Invoke(updateUIDelegate, args) End Sub 'Call from Web Service callback to UI thread Private Sub LoadAuthorsUpdateUI(ByRef newDs As DataSet) Try StatusBar1.Text = "Complete" If Not (newDs Is Nothing) Then Me.AuthorsDataSet1.Merge(newDs) StatusBar1.Text = "Record 1" End If Catch ex1 As Exception MsgBox(ex1.ToString) StatusBar1.Text = "Error Loading author information" Finally Me.Timer1.Stop() Me.Cursor = Cursors.Default While (Me.ProgressBar1.Value < Me.ProgressBar1.Maximum) Me.ProgressBar1.Value += Me.ProgressBar1.Step End While Me.ProgressBar1.Visible = False Me.ProgressBar1.Value = 0 End Try End Sub -----Original Message----- From: Simon Robinson [mailto:[EMAIL PROTECTED]] Sent: Friday, May 24, 2002 3:51 AM To: [EMAIL PROTECTED] Subject: [DOTNET] Displaying info on loading forms Two purposes to this post: 1. Ask a question 2. Mention some rather amusing behavior in Windows Forms. Questions runs... Is there any event in Windows Forms that is raised after a Form has been loaded? My form does a lot of processing at startup and I'd like it to display itself then do its processing, reporting to the user on its progress as it does it. I tried the Load event but that seems to get invoked just before the form is displayed. Amusing behavior runs... While looking for solutions to the above question I tried using the Activated event. The form contains a Panel and progress report would be written in the panel using Graphics.DrawString(). The result? 1. The main title bar of the form gets displayed (but not the rest of the form) 2. The calls to Graphics.DrawString() write the text over whatever happened to be on the screen where the form is going to be displayed. You end up with VS.NET sitting there with all this writing scrawled over it. 3. The form appears - but now without the writing. This quite tickled me - though I'm intrigued as to why it happened. I bet the Windows Forms team didn't intend it. Simon --------------------------------------------------------------- Simon Robinson http://www.SimonRobinson.com --------------------------------------------------------------- You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
