在VB6中要实现文件下载
般用和思路方法都是使用第 3方Control控件比如IEControl控件呀winscok呀但在本文中不用添加任何Control控件也不引用任何object就可实现文件下载而且
不支持文件下载进度捕获下载
激活下载完成事件等
具体思路方法:
1.新建
VB6工程(默认有个Form1窗体)2.选择工程菜单
“添加用户Control控件”来添加个用户Control控件3.更改Activex用户Control控件
名称更改为 Downloader (此项可省) 4.输入代码:(在用户Control控件
代码窗口中)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
Public Function CancelAsyncRead
As Boolean
On Error Resume Next
UserControl.CancelAsyncRead
End Function
'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
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 & ":" & Err.Description, vbCritical, ""
End Sub
'Public Sub SizeIt
' _disibledevent=
Private Sub Command1_Click
Downloader1.BeginDownload url, SaveFile
'请把 URL 替代为 Http://文件路径
'请把 savefile 替代为下载到本地文件路径和名称
End Sub
Private Sub Downloader1_DownloadComplete(MaxBytes As Long, SaveFile As String)
MsgBox "文件下载完成保存文件名为:" & SaveFile, vbInformation Or vbOKOnly, "提示:"
End Sub
Private Sub Downloader1_DownloadError(SaveFile As String)
MsgBox "下载发生！", vbExclamation Or vbOKOnly, ":"
End Sub
Private Sub Downloader1_DownloadProgress(CurBytes As Long, MaxBytes As Long, SaveFile As String)
'在这里添加进度第代码
End Sub
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