Let's say that we want to download a file named image.jpg at http://www.server.com/museums. We can do that with the Internet Transfer control, as you might expect. We fill a binary array with the data from the binary file and pass the icByteArray parameter to OpenURL() to indicate that we are downloading binary data:
Private Sub GetFile_Click()
—> Dim binarydata() As Byte
RichTextBox1.Text =
Inet1.OpenURL("http://www.microsoft.com/vbasic/default.htm")
—> binarydata() =
Inet1.OpenURL("http://www.server.com/museums/image.jpg", icByteArray)
.
.
.
End SubNow that the file has been loaded into the binary array, we store the file on disk:
Private Sub GetFile_Click()
Dim binarydata() As Byte
RichTextBox1.Text =
Inet1.OpenURL("http://www.microsoft.com/vbasic/default.htm")
binarydata() =
Inet1.OpenURL("http://www.server.com/museums/image.jpg", icByteArray)
—> Open "E:\vb\image.jpg" For Binary Access Write As #1
—> Put #1, , binarydata()
—> Close #1
.
.
.
End SubFinally, let's put a message box on the screen indicating that we have finished our downloading operations. (This code would be placed in the Internet Transfer control's StateChanged event handler if you were using the asynchronous Execute method.)
Private Sub GetFile_Click()
Dim binarydata() As Byte
RichTextBox1.Text =
Inet1.OpenURL("http://www.microsoft.com/vbasic/default.htm")
binarydata() =
Inet1.OpenURL("http://www.server.com/museums/image.jpg", icByteArray)
Open "E:\vb\image.jpg" For Binary Access Write As #1
Put #1, , binarydata()
Close #1
—> MsgBox "Finished."
End SubNow we can download binary files as well as text files. Using the Internet Transfer control, the process is easy: we just use OpenURL() or the Execute() method, and Visual Basic handles the rest. The code for the HTTPer project appears in Listing 3.2.
Listing 3.2 (HTTPer) FrmMain.frm
VERSION 5.00
Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.1#0"; "COMDLG32.OCX"
Object = "{6B7E6392-850A-101B-AFC0-4210102A8DA7}#1.1#0"; "COMCTL32.OCX"
Object = "{48E59290-9880-11CF-9754-00AA00C00908}#1.0#0"; "MSINET.OCX"
Object = "{3B7C8863-D78F-101B-B9B5-04021C009402}#1.1#0"; "RICHTX32.OCX"
Begin VB.Form frmMain
Caption = "HTTPer"
ClientHeight = 4050
ClientLeft = 165
ClientTop = 735
ClientWidth = 6315
LinkTopic = "Form1"
ScaleHeight = 4050
ScaleWidth = 6315
StartUpPosition = 3 'Windows Default
Begin ComctlLib.Toolbar tbToolBar
Align = 1 'Align Top
Height = 420
Left = 0
TabIndex = 1
Top = 0
Width = 6315
_ExtentX = 11139
_ExtentY = 741
ButtonWidth = 635
ButtonHeight = 582
Appearance = 1
ImageList = "imlIcons"
BeginProperty Buttons {7791BA41-E020-11CF-8E74-00A0C90F26F8}
NumButtons = 17
BeginProperty Button1 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "New"
Object.ToolTipText = "New"
Object.Tag = ""
ImageIndex = 1
EndProperty
BeginProperty Button2 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Open"
Object.ToolTipText = "Open"
Object.Tag = ""
ImageIndex = 2
EndProperty
BeginProperty Button3 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Save"
Object.ToolTipText = "Save"
Object.Tag = ""
ImageIndex = 3
EndProperty
BeginProperty Button4 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Object.Tag = ""
Style = 3
EndProperty
BeginProperty Button5 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Print"
Object.ToolTipText = "Print"
Object.Tag = ""
ImageIndex = 4
EndProperty
BeginProperty Button6 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Object.Tag = ""
Style = 3
EndProperty
BeginProperty Button7 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Cut"
Object.ToolTipText = "Cut"
Object.Tag = ""
ImageIndex = 5
EndProperty
BeginProperty Button8 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Copy"
Object.ToolTipText = "Copy"
Object.Tag = ""
ImageIndex = 6
EndProperty
BeginProperty Button9 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Paste"
Object.ToolTipText = "Paste"
Object.Tag = ""
ImageIndex = 7
EndProperty
BeginProperty Button10 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Object.Tag = ""
Style = 3
EndProperty
BeginProperty Button11 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Bold"
Object.ToolTipText = "Bold"
Object.Tag = ""
ImageIndex = 8EndProperty
BeginProperty Button12 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Italic"
Object.ToolTipText = "Italic"
Object.Tag = ""
ImageIndex = 9
EndProperty
BeginProperty Button13 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Underline"
Object.ToolTipText = "Underline"
Object.Tag = ""
ImageIndex = 10
EndProperty
BeginProperty Button14 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Object.Tag = ""
Style = 3
EndProperty
BeginProperty Button15 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Left"
Object.ToolTipText = "Left Justify"
Object.Tag = ""
ImageIndex = 11
EndProperty
BeginProperty Button16 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Center"
Object.ToolTipText = "Center"
Object.Tag = ""
ImageIndex = 12
EndProperty
BeginProperty Button17 {7791BA43-E020-11CF-8E74-00A0C90F26F8}
Key = "Right"
Object.ToolTipText = "Right Justify"
Object.Tag = ""
ImageIndex = 13
EndProperty
EndProperty
End
Begin ComctlLib.StatusBar sbStatusBar
Align = 2 'Align Bottom
Height = 270
Left = 0
TabIndex = 0
Top = 3780
Width = 6315
_ExtentX = 11139
_ExtentY = 476
SimpleText = ""
BeginProperty Panels {2C787A51-E01C-11CF-8E74-00A0C90F26F8}
NumPanels = 3
BeginProperty Panel1 {2C787A53-E01C-11CF-8E74-00A0C90F26F8}
AutoSize = 1
Object.Width = 5503
MinWidth = 2540
Text = "Status"
TextSave = "Status"
Object.Tag = ""
EndProperty
BeginProperty Panel2 {2C787A53-E01C-11CF-8E74-00A0C90F26F8}
Style = 6
AutoSize = 2
Object.Width = 2540
MinWidth = 2540
TextSave = "12/4/96"
Object.Tag = ""
EndProperty
BeginProperty Panel3 {2C787A53-E01C-11CF-8E74-00A0C90F26F8}
Style = 5
AutoSize = 2
Object.Width = 2540
MinWidth = 2540
TextSave = "9:25 PM"
Object.Tag = ""
EndProperty
EndProperty
BeginProperty Font {0BE35203-8F91-11CE-9DE3-00AA004BB851}
Name = "MS Sans Serif"
Size = 8.25
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
End
Begin MSComDlg.CommonDialog dlgCommonDialog
Left = 1740
Top = 1350
_ExtentX = 847
_ExtentY = 847
FontSize = 1.87933e-37
End
Begin InetCtlsObjects.Inet Inet1
Left = 2040
Top = 1320
_ExtentX = 1005
_ExtentY = 1005
EndBegin RichTextLib.RichTextBox RichTextBox1
Height = 3135
Left = 120
TabIndex = 2
Top = 600
Width = 6015
_ExtentX = 10610
_ExtentY = 5530
ScrollBars = 3
TextRTF = $"frmMain.frx":0000
End
Begin ComctlLib.ImageList imlIcons
Left = 1740
Top = 1350
_ExtentX = 1005
_ExtentY = 1005
BackColor = -2147483643
ImageWidth = 16
ImageHeight = 16
MaskColor = 12632256
BeginProperty Images {8556BCD1-E01E-11CF-8E74-00A0C90F26F8}
NumListImages = 13
BeginProperty ListImage1 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":00D2
Key = ""
EndProperty
BeginProperty ListImage2 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":0424
Key = ""
EndProperty
BeginProperty ListImage3 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":0776
Key = ""
EndProperty
BeginProperty ListImage4 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":0AC8
Key = ""
EndProperty
BeginProperty ListImage5 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":0E1A
Key = ""
EndProperty
BeginProperty ListImage6 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":116C
Key = ""
EndProperty
BeginProperty ListImage7 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":14BE
Key = ""
EndProperty
BeginProperty ListImage8 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":1810
Key = ""
EndProperty
BeginProperty ListImage9 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":1B62
Key = ""
EndProperty
BeginProperty ListImage10 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":1EB4
Key = ""
EndProperty
BeginProperty ListImage11 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":2206
Key = ""
EndProperty
BeginProperty ListImage12 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":2558
Key = ""
EndProperty
BeginProperty ListImage13 {8556BCD3-E01E-11CF-8E74-00A0C90F26F8}
Picture = "frmMain.frx":28AA
Key = ""
EndProperty
EndProperty
End
Begin VB.Menu mnuFile
Caption = "&File"
Begin VB.Menu mnuFileNew
Caption = "&New"
Shortcut = ^N
End
Begin VB.Menu mnuFileOpen
Caption = "&Open"
Shortcut = ^O
End
Begin VB.Menu mnuFileClose
Caption = "&Close"
End
Begin VB.Menu GetFile
Caption = "Get File"
End
Begin VB.Menu mnuFileBar1
Caption = "-"
End
Begin VB.Menu mnuFileSave
Caption = "&Save"Shortcut = ^S
End
Begin VB.Menu mnuFileSaveAs
Caption = "Save &As..."
End
Begin VB.Menu mnuFileSaveAll
Caption = "Save A&ll"
End
Begin VB.Menu mnuFileBar2
Caption = "-"
End
Begin VB.Menu mnuFileProperties
Caption = "Propert&ies"
End
Begin VB.Menu mnuFileBar3
Caption = "-"
End
Begin VB.Menu mnuFilePageSetup
Caption = "Page Set&up..."
End
Begin VB.Menu mnuFilePrintPreview
Caption = "Print Pre&view"
End
Begin VB.Menu mnuFilePrint
Caption = "&Print..."
Shortcut = ^P
End
Begin VB.Menu mnuFileBar4
Caption = "-"
End
Begin VB.Menu mnuFileSend
Caption = "Sen&d..."
End
Begin VB.Menu mnuFileBar5
Caption = "-"
End
Begin VB.Menu mnuFileMRU
Caption = ""
Index = 0
Visible = 0 'False
End
Begin VB.Menu mnuFileMRU
Caption = ""
Index = 1
Visible = 0 'False
End
Begin VB.Menu mnuFileMRU
Caption = ""
Index = 2
Visible = 0 'False
End
Begin VB.Menu mnuFileMRU
Caption = ""
Index = 3
Visible = 0 'False
End
Begin VB.Menu mnuFileBar6
Caption = "-"
Visible = 0 'False
End
Begin VB.Menu mnuFileExit
Caption = "E&xit"
End
End
Begin VB.Menu mnuEdit
Caption = "&Edit"
Begin VB.Menu mnuEditUndo
Caption = "&Undo"
Shortcut = ^Z
End
Begin VB.Menu mnuEditBar1
Caption = "-"
End
Begin VB.Menu mnuEditCut
Caption = "Cu&t"
Shortcut = ^X
End
Begin VB.Menu mnuEditCopy
Caption = "&Copy"
Shortcut = ^C
End
Begin VB.Menu mnuEditPaste
Caption = "&Paste"
Shortcut = ^V
End
Begin VB.Menu mnuEditPasteSpecial
Caption = "Paste &Special..."
End
End
Begin VB.Menu mnuHelp
Caption = "&Help"
Begin VB.Menu mnuHelpContents
Caption = "&Contents"
End
Begin VB.Menu mnuHelpSearch
Caption = "&Search For Help On..."
EndBegin VB.Menu mnuHelpBar1
Caption = "-"
End
Begin VB.Menu mnuHelpAbout
Caption = "&About HTTPer..."
End
End
End
Attribute VB_Name = "frmMain"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Declare Function OSWinHelp% Lib "user32" Alias "WinHelpA" (ByVal hwnd&, ByVal HelpFile$, ByVal wCommand%, dwData As Any)
Private Sub Form_Load()
Me.Left = GetSetting(App.Title, "Settings", "MainLeft", 1000)
Me.Top = GetSetting(App.Title, "Settings", "MainTop", 1000)
Me.Width = GetSetting(App.Title, "Settings", "MainWidth", 6500)
Me.Height = GetSetting(App.Title, "Settings", "MainHeight", 6500)
End Sub
Private Sub Form_Unload(Cancel As Integer)
If Me.WindowState <> vbMinimized Then
SaveSetting App.Title, "Settings", "MainLeft", Me.Left
SaveSetting App.Title, "Settings", "MainTop", Me.Top
SaveSetting App.Title, "Settings", "MainWidth", Me.Width
SaveSetting App.Title, "Settings", "MainHeight", Me.Height
End If
End Sub
Private Sub GetFile_Click()
Dim binarydata() As Byte
RichTextBox1.Text =
Inet1.OpenURL("http://www.microsoft.com/vbasic/default.htm")
binarydata() =
Inet1.OpenURL("http://www.server.com/museums/image.jpg", icByteArray)
Open "E:\vb\image.jpg" For Binary Access Write As #1
Put #1, , binarydata()
Close #1
MsgBox "Finished."
End Sub
Private Sub mnuHelpAbout_Click()
'To Do
MsgBox "About Box Code goes here!"
End Sub
Private Sub tbToolBar_ButtonClick(ByVal Button As ComctlLib.Button)
Select Case Button.Key
Case "New"
mnuFileNew_Click
Case "New"
mnuFileNew_Click
Case "Open"
mnuFileOpen_Click
Case "Save"
mnuFileSave_Click
Case "Print"
mnuFilePrint_Click
Case "Cut"
mnuEditCut_Click
Case "Copy"
mnuEditCopy_Click
Case "Paste"
mnuEditPaste_Click
Case "Bold"
'To Do
MsgBox "Bold Code goes here!"
Case "Italic"
'To Do
MsgBox "Italic Code goes here!"
Case "Underline"
'To Do
MsgBox "Underline Code goes here!"
Case "Left"
'To Do
MsgBox "Left Code goes here!"
Case "Center"
'To Do
MsgBox "Center Code goes here!"
Case "Right"'To Do
MsgBox "Right Code goes here!"
End Select
End Sub
Private Sub mnuHelpContents_Click()
Dim nRet As Integer
'if there is no helpfile for this project display a message to the user
'you can set the HelpFile for your application in the
'Project Properties dialog
If Len(App.HelpFile) = 0 Then
MsgBox "Unable to display Help Contents. There is no Help associated with this project.", vbInformation, Me.Caption
Else
On Error Resume Next
nRet = OSWinHelp(Me.hwnd, App.HelpFile, 3, 0)
If Err Then
MsgBox Err.Description
End If
End If
End Sub
Private Sub mnuHelpSearch_Click()
Dim nRet As Integer
'if there is no helpfile for this project display a message to the user
'you can set the HelpFile for your application in the
'Project Properties dialog
If Len(App.HelpFile) = 0 Then
MsgBox "Unable to display Help Contents. There is no Help associated with this project.", vbInformation, Me.Caption
Else
On Error Resume Next
nRet = OSWinHelp(Me.hwnd, App.HelpFile, 261, 0)
If Err Then
MsgBox Err.Description
End If
End If
End Sub
Private Sub mnuEditCopy_Click()
'To Do
MsgBox "Copy Code goes here!"
End Sub
Private Sub mnuEditCut_Click()
'To Do
MsgBox "Cut Code goes here!"
End Sub
Private Sub mnuEditPaste_Click()
'To Do
MsgBox "Paste Code goes here!"
End Sub
Private Sub mnuEditPasteSpecial_Click()
'To Do
MsgBox "Paste Special Code goes here!"
End Sub
Private Sub mnuEditUndo_Click()
'To Do
MsgBox "Undo Code goes here!"
End Sub
Private Sub mnuFileOpen_Click()
Dim sFile As String
With dlgCommonDialog
'To Do
'set the flags and attributes of the
'common dialog control
.Filter = "All Files (*.*)|*.*".ShowOpen
If Len(.filename) = 0 Then
Exit Sub
End If
sFile = .filename
End With
'To Do
'process the opened file
End Sub
Private Sub mnuFileClose_Click()
'To Do
MsgBox "Close Code goes here!"
End Sub
Private Sub mnuFileSave_Click()
'To Do
MsgBox "Save Code goes here!"
End Sub
Private Sub mnuFileSaveAs_Click()
'To Do
'Set up the common dialog control
'prior to calling ShowSave
dlgCommonDialog.ShowSave
End Sub
Private Sub mnuFileSaveAll_Click()
'To Do
MsgBox "Save All Code goes here!"
End Sub
Private Sub mnuFileProperties_Click()
'To Do
MsgBox "Properties Code goes here!"
End Sub
Private Sub mnuFilePageSetup_Click()
dlgCommonDialog.ShowPrinter
End Sub
Private Sub mnuFilePrintPreview_Click()
'To Do
MsgBox "Print Preview Code goes here!"
End Sub
Private Sub mnuFilePrint_Click()
'To Do
MsgBox "Print Code goes here!"
End Sub
Private Sub mnuFileSend_Click()
'To Do
MsgBox "Send Code goes here!"
End Sub
Private Sub mnuFileMRU_Click(Index As Integer)
'To Do
MsgBox "MRU Code goes here!"
End Sub
Private Sub mnuFileExit_Click()
'unload the form
Unload MeEnd Sub
Private Sub mnuFileNew_Click()
'To Do
MsgBox "New File Code goes here!"
End Sub
That's it for our coverage of the FTP and HTTP protocols for the moment. In this chapter we've worked with powerful methods of interacting with the Internet using these protocols. We've discussed the Execute() method, FTP commands such as CD, MKDIR, GET, PUT, and DIR, and the HTTP commands GET, HEAD, POST, and PUT, as well as the OpenURL() method, which handles a great many of the details. In the next chapter, we'll continue our exploration of Visual Basic on the Internet when we turn to email.