如何用VB做下载工具
- 提问者网友：不爱我么
- 2021-06-04 20:36
- 五星知识达人网友：鱼芗
- 2021-06-04 21:43
窗体1
Option Explicit
Dim WithEvents tg As DownLoad
Dim tmp As Long
Private Sub Command1_Click()
Command1.Enabled = False
tg.URL = T1 '设置下载地址
tg.SaveFile = T2 '下载后的文件存放位置
tg.Execute '连接网络
tmp = CLng(tg.GetHeader("Content-Length")) '获取下载文件大小
tg.StartDownLoad '开始下载
Command1.Enabled = True
End Sub
Private Sub Command2_Click()
tg.Cancel
End Sub
Private Sub Form_Load()
Set tg = New DownLoad
T1 = " http://wo196157629.gicp.net/lz/社区管理系统.exe"
T2 = App.Path & "\setup.exe"
Command1.Caption = "下载1"
Command3.Caption = "停止1"
End Sub
Private Sub tg_DownLoadOver()
MsgBox "下载成功！", vbInformation, "提示"
End Sub
Private Sub tg_ErrMassage(Description As String)
'错误信息
MsgBox Description, vbCritical, "错误"
End Sub
Private Sub tg_GetData(Progress As Long)
'Progress返回的是已下载的数据大小
L = Format$(Progress, "###,###") & "/" & Format$(tmp, "###,###")
End Sub
类模块 名 DownLoad
Option Explicit
Private Declare Function InternetOpen Lib "wininet" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long
Private Declare Function InternetCloseHandle Lib "wininet" (ByRef hInet As Long) As Long
Private Declare Function InternetReadFile Lib "wininet" (ByVal hFile As Long, sBuffer As Byte, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer
Private Declare Function InternetOpenUrl Lib "wininet" Alias "InternetOpenUrlA" (ByVal hInternetSession As Long, ByVal lpszUrl As String, ByVal lpszHeaders As String, ByVal dwHeadersLength As Long, ByVal dwFlags As Long, ByVal dwContext As Long) As Long
Private Declare Function HttpQueryInfo Lib "wininet.dll" Alias "HttpQueryInfoA" (ByVal hHttpRequest As Long, ByVal lInfoLevel As Long, ByVal sBuffer As Any, ByRef lBufferLength As Long, ByRef lIndex As Long) As Integer
Private Const INTERNET_OPEN_TYPE_PRECONFIG = 0
Private Const scUserAgent = "Tgwang"
Private Const INTERNET_OPEN_TYPE_DIRECT = 1
Private Const INTERNET_OPEN_TYPE_PROXY = 3
Private Const INTERNET_FLAG_RELOAD = &H80000000
Private mvarUrl As String
Private mvarSaveFile As String
Private mvarConnect As Boolean
Private hOpen As Long, hFile As Long
Private Buffer As String, BufLen As Long
Private RetQueryInfo As Boolean
Public Event GetData(Progress As Long) '下载进度
Public Event ErrMassage(Description As String) '错误信息
Public Event DownLoadOver()
Public Sub Execute()
mvarConnect = True
hOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_DIRECT, vbNullString, vbNullString, 0)
If mvarConnect = False Then
Cancel
Exit Sub
End If
If hOpen = 0 Then
Cancel
RaiseEvent ErrMassage("无法创建连接")
mvarConnect = False
Else
hFile = InternetOpenUrl(hOpen, mvarUrl, vbNullString, ByVal 0&, INTERNET_FLAG_RELOAD, ByVal 0&)
If mvarConnect = False Then
Cancel
Exit Sub
End If
If hFile = 0 Then
Cancel
RaiseEvent ErrMassage("无法连接服务器")
mvarConnect = False
Else
Buffer = Space$(1024)
BufLen = 1024
RetQueryInfo = HttpQueryInfo(hFile, 21, Buffer, BufLen, 0)
If RetQueryInfo Then
Buffer = Mid$(Buffer, 1, BufLen)
Else
Buffer = ""
End If
End If
End If
End Sub
'Public Function FileSize() As Long
' FileSize = GetHeader("Content-Length")
'End Function
Public Function StartDownLoad() As Boolean
Dim sBuffer(1 To 1024) As Byte, Ret As Long
Dim intfile As Long, LBR As Long
Dim i As Long
If mvarConnect = False Then
Cancel
StartDownLoad = False
Exit Function
End If
On Error GoTo OutErr
Err.Clear
'If Dir$(mvarSaveFile) > " " Then
' Name mvarSaveFile As mvarSaveFile & ".bak"
'End If
If Len(Dir$(mvarSaveFile)) > 0 Then
If MsgBox("目标文件以存在是否覆盖!", vbInformation + vbYesNo, "提示") = vbNo Then
Cancel
StartDownLoad = False
Exit Function
End If
End If
intfile = FreeFile()
Open mvarSaveFile For Binary Access Write As #intfile
Do
InternetReadFile hFile, sBuffer(1), 1024, Ret
DoEvents
If Ret = 1024 Then
If mvarConnect = False Then
StartDownLoad = False
GoTo Quit
End If
Put #1, , sBuffer
Else
For i = 1 To Ret
Put #1, , sBuffer(i)
DoEvents
Next i
End If
LBR = LBR + Ret
RaiseEvent GetData(LBR)
DoEvents
Loop Until Ret < 1024
RaiseEvent DownLoadOver
Quit:
Close #intfile
'if Dir$(mvarSaveFile & ".bak") > " " Then
' Kill mvarSaveFile
' Name mvarSaveFile & ".bak" As mvarSaveFile
'End If
Cancel
Exit Function
OutErr:
Err.Clear
Cancel
Close #intfile
RaiseEvent ErrMassage("文件" & mvarSaveFile & "正在使用,无法进行操作")
On Error GoTo 0
End Function
Public Sub Cancel()
mvarConnect = False
InternetCloseHandle hOpen
InternetCloseHandle hFile
End Sub
Public Property Let SaveFile(ByVal FileName As String)
mvarSaveFile = FileName
End Property
Public Property Let URL(ByVal URL As String)
mvarUrl = URL
End Property
Public Function GetHeader(Optional hdrName As String) As String
Dim tmp As Long
Dim tmp2 As String
If mvarConnect = False Then
GetHeader = "0"
Cancel
Exit Function
End If
If Buffer <> "" Then
Select Case UCase$(hdrName)
Case "CONTENT-LENGTH"
tmp = InStr(Buffer, "Content-Length")
tmp2 = Mid$(Buffer, tmp + 16, Len(Buffer))
tmp = InStr(tmp2, Chr$(0))
GetHeader = CStr(Mid$(tmp2, 1, tmp - 1))
Case "CONTENT-TYPE"
tmp = InStr(Buffer, "Content-Type")
tmp2 = Mid$(Buffer, tmp + 14, Len(Buffer))
tmp = InStr(tmp2, Chr$(0))
GetHeader = CStr(Mid$(tmp2, 1, tmp - 1))
Case "DATE"
tmp = InStr(Buffer, "Date")
tmp2 = Mid$(Buffer, tmp + 6, Len(Buffer))
tmp = InStr(tmp2, Chr$(0))
GetHeader = CStr(Mid$(tmp2, 1, tmp - 1))
Case "LAST-MODIFIED"
tmp = InStr(Buffer, "Last-Modified")
tmp2 = Mid$(Buffer, tmp + 15, Len(Buffer))
tmp = InStr(tmp2, Chr$(0))
GetHeader = CStr(Mid$(tmp2, 1, tmp - 1))
Case "SERVER"
tmp = InStr(Buffer, "Server")
tmp2 = Mid$(Buffer, tmp + 8, Len(Buffer))
tmp = InStr(tmp2, Chr$(0))
GetHeader = CStr(Mid$(tmp2, 1, tmp - 1))
Case vbNullString
GetHeader = Buffer
Case Else
GetHeader = "0"
End Select
Else
GetHeader = "0"
End If
End Function
- 1楼网友：纵马山川剑自提
- 2021-06-04 22:27
你好
我这里有VB做的下载程序
如果想要的，可以加的QQ373903757
- 2楼网友：枭雄戏美人
- 2021-06-04 22:09
二个按钮 一个文本用来输入下载地址的 Private Declare Function DoFileDownload Lib "shdocvw.dll" _ (ByVal lpszFile As String) As Long
Private Sub Form_Load() Text1.Text = " http://www.mingrisoft.com" End Sub
Private Sub Command1_Click() '下载 Dim sDownload As String sDownload = StrConv(Text1.Text, vbUnicode) Call DoFileDownload(sDownload) End Sub
Private Sub Command2_Click() End End Sub