|
|
|
|
|
|
|
|
|
|
|
 |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prerequisites |
| Version 4.71 and later of Shlwapi.dll. |
|
|
 Windows
Shlwapi.dll exposes a great number of path-oriented functions designed for use by the Windows shell. For more information on the shell
APIs please see PathFileExists: A Local/Network File/Folder/Drive Exists Routine.
This page demonstrates using PathFindNextComponent to recursively parse a path to extract each element from the path, beginning after the drive designation. Since PathFindNextComponent parses a path for the next path component, by passing the result of the previous call each path value returned represents the remainder of the path, minus one element. Note that the call works from the left, so the last item returned is the file and extension. Note this API has no effect on IP or URL paths. In order to show a complete demo using a combination of path and file strings representing typical application needs, each demo uses the same 26 strings as its test bed. This provides the opportunity to see exactly how each category of path information is handled by a specific call, as well as provide a single test bed upon which you can reuse the form while building a BAS module that contains just the functions you need. This demo uses a modification of the standard strings found in the previous demo. The code to align the label with the textboxes is hard-coded for positions designed for systems with small fonts. The form code below creates and labels the controls appropriate for this demo by just placing a single text box and label on the form, and setting the index of each to 0 in order to create a control array. |
| BAS Module Code |
|
| Place the following code into the general declarations area of a bas module: |
|
|
Option Explicit '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Copyright ©1996-2011 VBnet/Randy Birch, All Rights Reserved. ' Some pages may also contain other copyrights by the author. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Distribution: You can freely use this code in your own ' applications, but you may not reproduce ' or publish this code on any web site, ' online service, or distribute as source ' on any media without express permission. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' Private Declare Function PathFindNextComponent Lib "shlwapi" _
Alias "PathFindNextComponentA" _
(ByVal pPath As String) As Long
Private Declare Function lstrcpyA Lib "kernel32" _
(ByVal RetVal As String, _
ByVal Ptr As Long) As Long
Private Declare Function lstrlenA Lib "kernel32" _
(ByVal Ptr As Any) As Long
Public Function GetNextPathElement(ByVal sPath As String) As String
'Parses a path for the next path component
'after the root. Paths are delimited by
'backslashes or by the NULL at the end of
'the path.
GetNextPathElement = GetStrFromPtrA(PathFindNextComponent(sPath))
End Function
Private Function GetStrFromPtrA(ByVal lpszA As Long) As String
'Given a pointer to a string, return the string
GetStrFromPtrA = String$(lstrlenA(ByVal lpszA), 0)
Call lstrcpyA(ByVal GetStrFromPtrA, ByVal lpszA)
End Function |
| Form Code |
|
| Add one label (Label1), one text box (Text1) to a form. Set the index property of each to 0 to create control arrays; the demo load event code will create and label the needed controls. Add a command button (Command1), along with the following code: |
|
|
Option Explicit
Private Form_Load
Dim cnt As Long
For cnt = 0 To 22
If cnt > 0 Then Load Text1(cnt)
With Text1(cnt)
.Left = 3700
.Top = 210 + (300 * cnt)
.Width = 3000
.Visible = True
End With
Next
For cnt = 0 To 4
If cnt > 0 Then Load Label1(cnt)
With Label1(cnt)
.Left = 120
.Visible = True
End With
Next
Label1(0).Top = 300
Label1(1).Top = 1450
Label1(2).Top = 3000
Label1(3).Top = 4150
Label1(4).Top = 5650
With Command1
.Left = 300
.Top = Text1(22).Top + (Text1(18).Height * 1.5)
.Width = 1935
.Caption = "GetNextPathElement"
End With
'display the strings that will be used in the call
'absolute path
Label1(0).Caption = "c:\path1\path2\path3\somefile.txt"
'relative path
Label1(1).Caption = "..\..\path1\path2\path3\somefile.txt"
'mapped drive
Label1(2).Caption = "m:\path1\path2\path3\somefile.txt"
'UNC
Label1(3).Caption = "\\workstation\path1\path2\path3\somefile.txt"
'IP address
Label1(4).Caption = "\\192.168.1.100\path1\path2\path3\somefile.txt"
End Sub
Private Sub Command1_Click()
'Parses a path for the next path component
'after the root. Paths are delimited by
'backslashes or by the NULL at the end of
'the path.
Dim tmp As String
Dim cnt As Long
tmp = Label1(0).Caption
For cnt = 0 To 3
tmp = GetNextPathElement(tmp)
Text1(cnt).Text = tmp
Next
tmp = Label1(1).Caption
For cnt = 4 To 8
tmp = GetNextPathElement(tmp)
Text1(cnt).Text = tmp
Next
tmp = Label1(2).Caption
For cnt = 9 To 12
tmp = GetNextPathElement(tmp)
Text1(cnt).Text = tmp
Next
tmp = Label1(3).Caption
For cnt = 13 To 17
tmp = GetNextPathElement(tmp)
Text1(cnt).Text = tmp
Next
tmp = Label1(4).Caption
For cnt = 18 To 22
tmp = GetNextPathElement(tmp)
Text1(cnt).Text = tmp
Next
End Sub |
| Comments |
|
|
|
|
|
|||||
|
|||||
|
|
|||||
|
Copyright ©1996-2011 VBnet and Randy Birch. All Rights Reserved. |
 |
