VB中异步的问题，如果中止异步和异步出错时怎样处理。

airon2002 2003-09-25 09:26:52

Option Explicit
Event DownloadProgress(CurBytes As Long, MaxBytes As Long, SaveFile As String)
Event DownloadError(SaveFile As String)
Event DownloadComplete(MaxBytes As Long, SaveFile As String)
Public downStat As Boolean
Private Sub UserControl_AsyncReadComplete(AsyncProp As AsyncProperty)
On Error Resume Next
Dim f() As Byte, fn As Long
If AsyncProp.BytesMax <> 0 Then
fn = FreeFile
f = AsyncProp.Value
Open AsyncProp.PropertyName For Binary Access Write As #fn
Put #fn, , f
Close #fn
Else
RaiseEvent DownloadError(AsyncProp.PropertyName)
End If
RaiseEvent DownloadComplete(CLng(AsyncProp.BytesMax), AsyncProp.PropertyName)
downStat = False
End Sub
Private Sub UserControl_AsyncReadProgress(AsyncProp As AsyncProperty)
On Error Resume Next
If AsyncProp.BytesMax <> 0 Then
RaiseEvent DownloadProgress(CLng(AsyncProp.BytesRead), CLng(AsyncProp.BytesMax), AsyncProp.PropertyName)
downStat = True: Timer1.Enabled = True
End If
End Sub
Private Sub UserControl_Resize()
SizeIt
End Sub
Public Sub BeginDownload(url As String, SaveFile As String)
On Error GoTo ErrorBeginDownload
downStat = True
UserControl.AsyncRead url, vbAsyncTypeByteArray, SaveFile, vbAsyncReadForceUpdate
Timer1.Enabled = True
Exit Sub
ErrorBeginDownload:
downStat = False
MsgBox Err & "开始下载数据失败！" _
& vbCrLf & vbCrLf & "错误：" & Err.Description, vbCritical, "错误"
End Sub
Public Sub SizeIt()
On Error GoTo ErrorSizeIt
With UserControl
.Width = ScaleX(32, vbPixels, vbTwips)
.Height = ScaleY(32, vbPixels, vbTwips)
End With
Exit Sub
ErrorSizeIt:
End Sub

这是一个下载的Activex OCX,不用任何控件就可从HTTP上下载文件，(一定要写在VB 的Activex OCX中！)，支持进度条。但出错后就不能中止异步，或异步执行不知如何中止，望高手指点！！！！！！！！！！！！！！！！！

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vbprg 2003-10-17

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airon2002 2003-09-28

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高手不见了

airon2002 2003-09-27

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airon2002 2003-09-27

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airon2002 2003-09-26

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imur 2003-09-26

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学习

aha99 2003-09-26

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xuexi

airon2002 2003-09-25

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Private Sub Timer1_Timer()
If Not downStat Then
Timer1.Enabled = False
Exit Sub
End If
Static Cs As Integer
If Cs > 2 Then Cs = 0
UserControl.Picture = P1(Cs).Picture
Cs = Cs + 1
DoEvents
End Sub
加入：

此代码无用，只是在下载时显示图片，好像其它下载软件一样，下地时有动画效果·

airon2002 2003-09-25