Dan Appleman's Visual Bas…s Guide to the Win32 API/Dan.Applmans.Visual.Basic.5.0.Programmers.Guide.To.The.Win32.API.1997.Ziff-Davis.Press.CD/VB5PG32.mdf/vbpg32/samples4/vbdll/vbdll.frm

Visual Basic Form | 1995-07-05 | 12.7 KB | 440 lines

VERSION 4.00
Begin VB.Form dllparam
   Caption         =   "DLL parameter tester"
   ClientHeight    =   4725
   ClientLeft      =   1080
   ClientTop       =   1515
   ClientWidth     =   7365
   BeginProperty Font
      name            =   "MS Sans Serif"
      charset         =   0
      weight          =   700
      size            =   8.25
      underline       =   0   'False
      italic          =   0   'False
      strikethrough   =   0   'False
   EndProperty
   Height          =   5130
   Left            =   1020
   LinkMode        =   1  'Source
   LinkTopic       =   "Form1"
   ScaleHeight     =   4725
   ScaleWidth      =   7365
   Top             =   1170
   Width           =   7485
   Begin VB.CommandButton cmdObj3
      Caption         =   "Changes Obj"
      Height          =   375
      Left            =   3720
      TabIndex        =   25
      Top             =   4140
      Width           =   1695
   End
   Begin VB.CommandButton cmdObj2
      Caption         =   "Object2"
      Height          =   375
      Left            =   5520
      TabIndex        =   24
      Top             =   3720
      Width           =   855
   End
   Begin VB.CommandButton cmdBytes
      Caption         =   "Bytes"
      Height          =   375
      Left            =   4440
      TabIndex        =   23
      Top             =   2160
      Width           =   855
   End
   Begin VB.CommandButton cmdRecObj
      Caption         =   "Receives Object"
      Height          =   375
      Left            =   3720
      TabIndex        =   22
      Top             =   3720
      Width           =   1695
   End
   Begin VB.CommandButton cmdDate
      Caption         =   "Date"
      Height          =   375
      Left            =   6480
      TabIndex        =   21
      Top             =   2160
      Width           =   735
   End
   Begin VB.CommandButton Command3
      Caption         =   "Variant ByRef"
      Height          =   375
      Left            =   5520
      TabIndex        =   20
      Top             =   3240
      Width           =   1695
   End
   Begin VB.CommandButton Command2
      Caption         =   "VariantByVal"
      Height          =   375
      Left            =   3720
      TabIndex        =   19
      Top             =   3240
      Width           =   1695
   End
   Begin VB.CommandButton Command1
      Caption         =   "VBArray"
      Height          =   375
      Left            =   5400
      TabIndex        =   18
      Top             =   2160
      Width           =   975
   End
   Begin VB.CommandButton TestIntByval
      Caption         =   "ReceivesInteger(5)"
      Height          =   375
      Left            =   240
      TabIndex        =   0
      Top             =   240
      Width           =   2175
   End
   Begin VB.CommandButton TestIntByref
      Caption         =   "Add5To5"
      Height          =   375
      Left            =   2640
      TabIndex        =   4
      Top             =   240
      Width           =   1575
   End
   Begin VB.CommandButton TestLongByval
      Caption         =   "ReceivesLong(6)"
      Height          =   375
      Left            =   240
      TabIndex        =   1
      Top             =   720
      Width           =   2175
   End
   Begin VB.CommandButton TestLongByref
      Caption         =   "Add5To6"
      Height          =   375
      Left            =   2640
      TabIndex        =   5
      Top             =   720
      Width           =   1575
   End
   Begin VB.CommandButton TestSingleByval
      Caption         =   "ReceivesSingle(1.59)"
      Height          =   375
      Left            =   240
      TabIndex        =   2
      Top             =   1200
      Width           =   2175
   End
   Begin VB.CommandButton TestSingleByref
      Caption         =   "Add5To1.59"
      Height          =   375
      Left            =   2640
      TabIndex        =   6
      Top             =   1200
      Width           =   1575
   End
   Begin VB.CommandButton TestCurrencyByval
      Caption         =   "ReceivesCurrency(1.2345)"
      Height          =   375
      Left            =   4440
      TabIndex        =   14
      Top             =   240
      Width           =   2775
   End
   Begin VB.CommandButton TestDoubleByval
      Caption         =   "ReceivesDouble(3.145)"
      Height          =   375
      Left            =   240
      TabIndex        =   3
      Top             =   1680
      Width           =   2175
   End
   Begin VB.CommandButton TestDoubleByref
      Caption         =   "Add5To3.145"
      Height          =   375
      Left            =   2640
      TabIndex        =   7
      Top             =   1680
      Width           =   1575
   End
   Begin VB.CommandButton TestCurrencyByref
      Caption         =   "AddPennyToCurrency(1.23)"
      Height          =   375
      Left            =   4440
      TabIndex        =   15
      Top             =   720
      Width           =   2775
   End
   Begin VB.CommandButton TestString
      Caption         =   "ReceivesString ""Hello"""
      Height          =   375
      Left            =   240
      TabIndex        =   8
      Top             =   2160
      Width           =   2175
   End
   Begin VB.CommandButton TestStringChange
      Caption         =   "Adds'!'to""Hello"""
      Height          =   375
      Left            =   2640
      TabIndex        =   9
      Top             =   2160
      Width           =   1575
   End
   Begin VB.CommandButton TestVBString
      Caption         =   "ReceivesVBString(""String to DLL"")"
      Height          =   375
      Left            =   240
      TabIndex        =   10
      Top             =   2760
      Width           =   3375
   End
   Begin VB.CommandButton TestUserType
      Caption         =   "ReceivesUserType(1,2,3,4)"
      Height          =   375
      Left            =   4440
      TabIndex        =   13
      Top             =   1200
      Width           =   2775
   End
   Begin VB.CommandButton TestVBStringChange
      Caption         =   "ChangesVBString(""Short"")"
      Height          =   375
      Left            =   240
      TabIndex        =   11
      Top             =   3240
      Width           =   3375
   End
   Begin VB.CommandButton TestAddUserString
      Caption         =   "AddUserString"
      Height          =   375
      Left            =   4440
      TabIndex        =   17
      Top             =   1680
      Width           =   1455
   End
   Begin VB.CommandButton ReceivesIArray
      Caption         =   "Int Array"
      Height          =   375
      Left            =   6000
      TabIndex        =   16
      Top             =   1680
      Width           =   1215
   End
   Begin VB.CommandButton ReturnVBString
      Caption         =   "ReturnsVBString()"
      Height          =   375
      Left            =   240
      TabIndex        =   12
      Top             =   3720
      Width           =   3375
   End
Attribute VB_Name = "dllparam"
Attribute VB_Creatable = False
Attribute VB_Exposed = False
' DLL parameter test program
' Copyright (c) 1995, by Desaware
' All rights reserved
' This program is used to test the VB/DLL interface
' functions defined in APIGid32.dll
Private Sub cmdBytes_Click()
    Dim b As Byte
    b = ReceivesBytes(65, 66)
    MsgBox "Received Byte " & Chr$(b)
End Sub
Private Sub cmdDate_Click()
    Dim d, t As Date
    d = Now()
    t = UsesDate(d)
    MsgBox "Tommorow is " & t
End Sub
Private Sub cmdObj2_Click()
    Dim o As Object
    Set o = ReceivesObject2(cmdObj2)
    MsgBox "Object caption is " & o.Caption
End Sub
Private Sub cmdObj3_Click()
    Dim orig$, final$
    Dim o As Object
    Set o = cmdObj3
    orig$ = o.Caption
    ChangesObject cmdObj2, o
    final$ = o.Caption
    MsgBox "Orig: " & orig$ & " Now: " & final$
End Sub
Private Sub cmdRecObj_Click()
    ReceivesObject cmdRecObj
End Sub
Private Sub Command1_Click()
    ReDim x(5) As Integer
    Dim y%
    x(0) = 5
    x(1) = 6
    x(2) = 7
    x(3) = 8
    x(4) = 9
    y% = ReceivesVBArray(x())
    MsgBox "New result of x(0) (was 5) is " & x(0)
End Sub
Private Sub Command2_Click()
    Dim v As Variant
    Dim res%
    v = "hello"
    res% = ReceivesVariantByVal(v)
End Sub
Private Sub Command3_Click()
    Dim v As Variant, rs As Variant
    Dim res%
    v = "hello"
    rs = ReceivesVariant(v)
    MsgBox "V is " & v
    MsgBox "rs is " & rs
End Sub
Private Sub Command4_Click()
End Sub
' This is a test of passing a pointer to a numeric array
' Note the unique DLL call
Private Sub ReceivesIArray_Click()
    ReDim x(4) As Integer
    Dim u As UserType
    Dim i As Integer
    x(0) = 1
    x(1) = 3
    x(2) = 9
    x(3) = 81
    ' Pass a pointer to the first element of the array.
    ' The DLL has no way of knowing how long the array is
    ' unless you define a length parameter for the function.
    ReceivesIntArray x(0)
    MsgBox "First entry is now " & x(0)
    ' Note that only the first value is correct, and
    ' that the change does not take effect
    u.e(0) = 88
    u.e(1) = 89
    u.e(2) = 90
    u.e(3) = 91
    ReceivesIntArray u.e(0)
    MsgBox "First entry is now " & u.e(0)
    u.a = 60
    u.b = 61
    u.c = 62
    u.d = 63
    ReceivesIntArray u.a
    MsgBox "First entry is now " & u.a
End Sub
' A DLL function returning a Visual Basic String
Private Sub ReturnVBString_Click()
    a$ = ReturnsVBString()
    MsgBox a$, 0, "ReturnsVBString"
End Sub
'   Show how to access strings inside user defined types
Private Sub TestAddUserString_Click()
    Dim u As UserType
    ' Note - this is call by reference, the DLL can change
    ' the value of u
    u.s = "orignal string"
    AddUserString u
    MsgBox u.s, 0, "String in usertype changed"
End Sub
' Passing currency by reference
Private Sub TestCurrencyByref_Click()
    Dim c@
    c@ = 1.23
    AddPennyToCurrency c@
    MsgBox Str$(c@), 0, "AddPennyToCurrency"
End Sub
' Passing currency by value and returning currency
Private Sub TestCurrencyByval_Click()
    Dim c@
    c = 1.2345
    c = ReceivesCurrency(c)
End Sub
' Passing doubles by reference
Private Sub TestDoubleByref_Click()
    d# = 3.145
    Add5ToDouble d#
    MsgBox Str$(d#), 0, "Add5ToDouble"
End Sub
' Passing doubles by value and returning doubles
Private Sub TestDoubleByval_Click()
    d# = ReceivesDouble(3.145)
End Sub
' Passing integers by reference
Private Sub TestIntByref_Click()
    x% = 5
    Add5ToInteger x%
    MsgBox Str$(x%), 0, "Add5ToInteger"
End Sub
' Passing integers by value and returning integers
Private Sub TestIntByval_Click()
    x% = ReceivesInteger(5)
End Sub
' Passing longs by reference
Private Sub TestLongByref_Click()
    y& = 6
    Add5ToLong y&
    MsgBox Str$(y&), 0, "Add5ToLong"
End Sub
' Passing longs by value and returning longs
Private Sub TestLongByval_Click()
    y& = ReceivesLong(6)
End Sub
' Passing singles by reference
Private Sub TestSingleByref_Click()
    f! = 1.59
    Add5ToSingle f!
    MsgBox Str$(f!), 0, "Add5ToSingle"
End Sub
' Passing singles by value and returning singles
Private Sub TestSingleByval_Click()
    f! = ReceivesSingle(1.59)
End Sub
' Passing strings (null terminated)
' Always by reference
Private Sub TestString_Click()
    ReceivesString "Hello"
End Sub
' Passing and modifying strings (null terminated)
' Always by reference
Private Sub TestStringChange_Click()
    ' Null terminated string is passed to the routine
    ' x$ must be preinitialized to the maximum length.
    ' The DLL may change the contents of the string, but
    ' must never go past the null terminator
    x$ = "Hello"
    ChangesString x$
    MsgBox x$, 0, "ChangesString"
End Sub
' Passing user defined types
' Always by reference
Private Sub TestUserType_Click()
    Dim u As UserType
    u.a = 1
    u.b = 2
    u.c = 3
    u.d = 4
    u.e(0) = 5
    u.e(1) = 6
    u.e(2) = 7
    u.e(3) = 8
    u.s2 = "ABCD"
    u.st = 99
    ' Note - this is call by reference, the DLL can change
    ' the value of u
    ReceivesUserType u
    u = ReturnUserType()
    MsgBox "New user type received: " & u.a & u.b & u.c & u.d
End Sub
' Passing Visual Basic strings
Private Sub TestVBString_Click()
    ReceivesVBString "String to DLL"
End Sub
' Passing and modifying Visual Basic strings
' Note - no length restrictions apply
Private Sub TestVBStringChange_Click()
    a$ = "Short"
    ChangesVBString a$
    MsgBox a$, 0, "ChangesVBString"
End Sub