Απ: Asynchronous execution και background Thread

RedHat — Sun, 22 Jan 2006 06:04:13 GMT

look and vb.net 2005 "backgroundWorker"

Απ: Asynchronous execution και background Thread

axaros — Wed, 05 Oct 2005 19:10:11 GMT

Μάνο ακριβώς το ίδιο πράγμα ζητάω (αν και δεν με ενδιέφερε το progress view) !!!
Θα το κοιτάξω και αν χρειαστεί θα επανέρθω.

Σε ευχαριστώ πολύ!!!

Απ: Asynchronous execution και background Thread

KelMan — Wed, 05 Oct 2005 07:15:14 GMT

Έχεις κοιτάξει αυτό http://www.dotnetzone.gr/cs/forums/1429/ShowPost.aspx το post?
Δεν έχω διαβάσει προσεκτικά τον κώδικά σου, αλλά νομίζω ότι πραγματεύεται περίπου το ίδιο θέμα...

Asynchronous execution και background Thread

axaros — Tue, 04 Oct 2005 17:22:08 GMT

Καλημέρα σε όλους !!!
Το πρόβλημα :
Θέλω να εκτελέσω ένα "βαρύ" statement αλλά και να δώσω τη δυνατότητα ακύρωσης στο χρήστη ανά πάσα στιγμή.
Χρησιμοποίησα ένα background thread. 'Ηθελα τη γνώμη σας :

Στο click Event μίας Win form σηκώνω modally μία άλλη (με ένα label με το κλασσικό "Παρακαλώ περιμένετε"
ένα PicureBox με κάποιο animated gif και ένα Cancel button)

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

Dim MyForm As New frmWait

   Try
      With DataGrid1
         .DataSource = Nothing
         .Refresh()
      End With

MyForm.ShowDialog(Me)

      With DataGrid1
         .DataSource = MyForm.Data
      End With

   Catch ex As Exception
      MsgBox(ex.Message)
   Finally
      MyForm.Dispose()
   End Try
End Sub

Ο κώδικας της frmWait είναι :

Imports System.Data
Imports System.Data.OleDb
Imports System.Threading
Imports System.Windows.Forms

Public Class frmWait
Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

      Public Sub New()
         MyBase.New()
         'This call is required by the Windows Form Designer.
         InitializeComponent()
         'Add any initialization after the InitializeComponent() call
      End Sub

      'Form overrides dispose to clean up the component list.
      Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
         If disposing Then
            If Not (components Is Nothing) Then
               components.Dispose()
            End If
         End If
         MyBase.Dispose(disposing)
      End Sub

   'Required by the Windows Form Designer
   Private components As System.ComponentModel.IContainer
   'NOTE: The following procedure is required by the Windows Form Designer
   'It can be modified using the Windows Form Designer.
   'Do not modify it using the code editor.
   Friend WithEvents Label1 As System.Windows.Forms.Label
   Friend WithEvents Button1 As System.Windows.Forms.Button
   Friend WithEvents PictureBox1 As System.Windows.Forms.PictureBox

<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(frmWait))

Me.Label1 = New System.Windows.Forms.Label
Me.Button1 = New System.Windows.Forms.Button
Me.PictureBox1 = New System.Windows.Forms.PictureBox

Me.SuspendLayout()

'Label1

Me.Label1.Font = New System.Drawing.Font("Tahoma", 9.75!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

Me.Label1.Location = New System.Drawing.Point(24, 128)

Me.Label1.Name = "Label1"

Me.Label1.Size = New System.Drawing.Size(157, 16)

Me.Label1.TabIndex = 0

Me.Label1.Text = "Παρακαλώ περιμένετε "

'Button1

Me.Button1.Location = New System.Drawing.Point(56, 160)

Me.Button1.Name = "Button1"

Me.Button1.Size = New System.Drawing.Size(80, 23)

Me.Button1.TabIndex = 1

Me.Button1.Text = "Ακύρωση"

'PictureBox1

Me.PictureBox1.Image = CType(resources.GetObject("PictureBox1.Image"), System.Drawing.Image)

Me.PictureBox1.Location = New System.Drawing.Point(40, 16)

Me.PictureBox1.Name = "PictureBox1"

Me.PictureBox1.Size = New System.Drawing.Size(112, 96)

Me.PictureBox1.TabIndex = 2

Me.PictureBox1.TabStop = False

'frmWait

Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)

Me.ClientSize = New System.Drawing.Size(190, 198)

Me.ControlBox = False

Me.Controls.Add(Me.PictureBox1)

Me.Controls.Add(Me.Button1)

Me.Controls.Add(Me.Label1)

Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle

Me.Name = "frmWait"

Me.ShowInTaskbar = False

Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen

Me.ResumeLayout(False)

End Sub

#End Region

   Private MyDTable As DataTable
   Protected Friend Property Data() As DataTable
      Get
         Data = MyDTable
      End Get
      Set(ByVal Value As DataTable)
         MyDTable = Value
      End Set
   End Property

Dim MyAsyncThread As Thread
Dim MyAsyncThreadStart As New ThreadStart(AddressOf GetData)

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Try

If MessageBox.Show("Θέλετε σίγουρα να ακυρώσετε την προεπισκόπηση" + _
   "των αποτελεσμάτων;", "Ακύρωση", MessageBoxButtons.YesNo, _
   MessageBoxIcon.Question, MessageBoxDefaultButton.Button2, _
   MessageBoxOptions.DefaultDesktopOnly) = DialogResult.No Then
   Exit Sub
End If

If MyAsyncThread.ThreadState = ThreadState.Background Then
   With MyAsyncThread
      .Sleep(0)
      .Abort()
      .Join()
   End With

               Application.DoEvents()
               Me.Data = Nothing
               Me.Close()
            End If

Catch Aex As ThreadAbortException

MsgBox("Operation aborted")

Catch Eex As ThreadStateException

MsgBox(Eex.Message)

Catch ex As Exception

Throw ex

End Try

End Sub

Private Sub GetData()

Dim MyDataset As New DataSet
Dim MyConnection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;" + _
"Data Source=C:\Atreus Co ltd\Sinp " + _
"Reporter\Database\TEST.mdb;")
Dim MyAdapter As New OleDbDataAdapter("SELECT * FROM VERY_LARGE_TABLE", _
                                                                                 MyConnection)

Try

MyDataset = New DataSet
MyConnection.Open()
MyAdapter.Fill(MyDataset, "TEST")
MyConnection.Close()

Me.Data = MyDataset.Tables(0)
Application.DoEvents()
Me.Close()

Catch ex As Exception
            Throw ex
Finally
            MyAdapter.Dispose()
            With MyConnection
               .Close()
               .Dispose()
            End With

End Try

End Sub

Private Sub frmWait_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load

   MyAsyncThread = New Thread(MyAsyncThreadStart)
   With MyAsyncThread
      .IsBackground = True
      .Name = "GetDataThread"
      .Start()
   End With

End Sub

End Class

.NET Framework

Απ: Asynchronous execution και background Thread

Απ: Asynchronous execution και background Thread

Απ: Asynchronous execution και background Thread

Asynchronous execution και background Thread