Multithreading....Where to begin?

[lolwtf]

Hi all,

I have a program which connects to sql and uses crystal reports. I have many records and crystal reports takes a while to load up. Would multi threading help improve performance? Here is my code:

Private Sub EmpLog_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim report As New Crystal_Report1
        report.SetParameterValue("EmployeeName", DSReport.Tables(0).Rows(0).Item("name"))
        report.SetDatabaseLogon("login", "password")

        CrystalReportViewer1.ReportSource = report

    End Sub

I want to somehow speed this up. Thanks in advance.

[kvprajapati]

lolwtf,
Use BackgroundWorker component - Read more about http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

[lolwtf]

Whats the differnece between the background worker and using threads? I'm kinda confused still.

[kvprajapati]

lolwtf,
You must read MSDN online page (link at - #2).
BackgroundWorker is a class that runs in a separate thread. When the BackgroundWorker class's thread calls a method, or does anything else with the Form, it is doing it in the context of its' own separate thread.

[lolwtf]

lolwtf,
You must read MSDN online page (link at - #2).
BackgroundWorker is a class that runs in a separate thread. When the BackgroundWorker class's thread calls a method, or does anything else with the Form, it is doing it in the context of its' own separate thread.

Okay i took a look at the article and incorporated some code into my project. The problem is i have another form that's coming up with a report viewer loading the crystal reports. Here is the code i added to the first form that loads the second with a button:

DBALog.SelectCommand.CommandText = "SELECT FName + ' ' + LName AS [name] FROM tblEmployee WHERE EmployeeID = " + DGVTime.SelectedRows(0).Cells("EmployeeID").Value.ToString + ";"
        Dim dsreport As New DataSet
        DBALog.Fill(dsreport)

        prgThread.Value = 0
        BackgroundWorker1.WorkerReportsProgress = True
        BackgroundWorker1.WorkerSupportsCancellation = True
        BackgroundWorker1.RunWorkerAsync()
        Dim newform As New EmpLog(dsreport)
        newform.MdiParent = Me.MdiParent
        newform.Size = Me.Size
        newform.Show()

Now heres the code for the other form:

Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Dim report As New Crystal_Report1
        report.SetParameterValue("EmployeeName", DSReport.Tables(0).Rows(0).Item("name"))
        report.SetDatabaseLogon("login", "password")

        CrystalReportViewer1.ReportSource = report


        

    End Sub

Normally i would put that code in the form load event. Now nothing displays in my report viewer. This is starting to get too advanced for my knowledge.