本文整理汇总了VB.NET中System.ComponentModel.BackgroundWorker.CancellationPending属性的典型用法代码示例。如果您正苦于以下问题:VB.NET BackgroundWorker.CancellationPending属性的具体用法?VB.NET BackgroundWorker.CancellationPending怎么用?VB.NET BackgroundWorker.CancellationPending使用的例子?那么, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类System.ComponentModel.BackgroundWorker
的用法示例。
在下文中一共展示了BackgroundWorker.CancellationPending属性的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: ComputeFibonacci
' Abort the operation if the user has canceled.
' Note that a call to CancelAsync may have set
' CancellationPending to true just after the
' last invocation of this method exits, so this
' code will not have the opportunity to set the
' DoWorkEventArgs.Cancel flag to true. This means
' that RunWorkerCompletedEventArgs.Cancelled will
' not be set to true in your RunWorkerCompleted
' event handler. This is a race condition.
If worker.CancellationPending Then
e.Cancel = True
Else
If n < 2 Then
result = 1
Else
result = ComputeFibonacci(n - 1, worker, e) + _
ComputeFibonacci(n - 2, worker, e)
End If
' Report progress as a percentage of the total task.
Dim percentComplete As Integer = _
CSng(n) / CSng(numberToCompute) * 100
If percentComplete > highestPercentageReached Then
highestPercentageReached = percentComplete
worker.ReportProgress(percentComplete)
End If
End If
示例2: MainClass
' 导入命名空间
Imports System
Imports System.Data
Imports System.Collections
Imports System.Windows.Forms
Imports System.Drawing
Imports System.Data.SqlClient
public class MainClass
Shared Sub Main()
Dim form1 As Form = New Form1
Application.Run(form1)
End Sub
End Class
Public Class Form1
Private Sub btnStartProcess_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnStartProcess.Click
btnStartProcess.Enabled = False
btnCancel.Enabled = True
prgLongProcess.Value = 0
bgrLongProcess.WorkerReportsProgress = True
bgrLongProcess.WorkerSupportsCancellation = True
bgrLongProcess.RunWorkerAsync()
End Sub
Private Sub btnCancel_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnCancel.Click
bgrLongProcess.CancelAsync()
End Sub
Private Sub bgrLongProcess_ProgressChanged(ByVal sender As Object, _
ByVal e As System.ComponentModel.ProgressChangedEventArgs) _
Handles bgrLongProcess.ProgressChanged
prgLongProcess.Value = e.ProgressPercentage
End Sub
Private Sub bgrLongProcess_RunWorkerCompleted(ByVal sender As Object, _
ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) _
Handles bgrLongProcess.RunWorkerCompleted
btnStartProcess.Enabled = True
btnCancel.Enabled = False
End Sub
Private Sub bgrLongProcess_DoWork(ByVal sender As Object, _
ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgrLongProcess.DoWork
For i As Integer = 1 To 10000
For j As Integer = 1 To 10000
Next j
If bgrLongProcess.CancellationPending Then Exit Sub
bgrLongProcess.ReportProgress(CInt(100 * i / 10000))
Next i
End Sub
End Class
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Public Class Form1
Inherits System.Windows.Forms.Form
'Form overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()> _
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
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.
<System.Diagnostics.DebuggerStepThrough()> _
Private Sub InitializeComponent()
Me.btnStartProcess = New System.Windows.Forms.Button
Me.btnCancel = New System.Windows.Forms.Button
Me.prgLongProcess = New System.Windows.Forms.ProgressBar
Me.bgrLongProcess = New System.ComponentModel.BackgroundWorker
Me.SuspendLayout()
'
'btnStartProcess
'
Me.btnStartProcess.Location = New System.Drawing.Point(8, 8)
Me.btnStartProcess.Name = "btnStartProcess"
Me.btnStartProcess.Size = New System.Drawing.Size(75, 23)
Me.btnStartProcess.TabIndex = 0
Me.btnStartProcess.Text = "Start"
'
'btnCancel
'
Me.btnCancel.Location = New System.Drawing.Point(208, 8)
Me.btnCancel.Name = "btnCancel"
Me.btnCancel.Size = New System.Drawing.Size(72, 24)
Me.btnCancel.TabIndex = 1
Me.btnCancel.Text = "Cancel"
Me.prgLongProcess.Location = New System.Drawing.Point(8, 48)
Me.prgLongProcess.Name = "prgLongProcess"
Me.prgLongProcess.Size = New System.Drawing.Size(272, 16)
Me.prgLongProcess.TabIndex = 2
Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
Me.ClientSize = New System.Drawing.Size(288, 75)
Me.Controls.Add(Me.prgLongProcess)
Me.Controls.Add(Me.btnCancel)
Me.Controls.Add(Me.btnStartProcess)
Me.Text = "UseBackgroundWorker"
Me.ResumeLayout(False)
End Sub
Friend WithEvents btnStartProcess As System.Windows.Forms.Button
Friend WithEvents btnCancel As System.Windows.Forms.Button
Friend WithEvents prgLongProcess As System.Windows.Forms.ProgressBar
Friend WithEvents bgrLongProcess As System.ComponentModel.BackgroundWorker
End Class