VB调用Delphi编写的DLL - 2

本篇讲程序2！

本程序主要有两个功能：计算CRC32数值和读取FCN文件的内容。

通过这个两个数值的对比可以发现是否文件被修改过！

1.按钮事件cmdCal_Click()

Label_cal.Caption = calCRC32(filePath1)

此接口有1个参数：

'定义要计算的文件(具体路径和文件名称)
  Dim filePath1 As String

外调函数声明：

'vb define
Option Explicit
Private Declare Function calCRC32 Lib "FCN.dll" (ByVal filePath1 As String) As Long

2.按钮事件cmdReadFCN_Click()

Label_read.Caption = readFCN(loadFile1)

此接口有1个参数：

  '定义要读取的文件(具体路径和文件名称)
  Dim loadFile1 As String

外调函数声明：

Private Declare Function readFCN Lib "FCN.dll" (ByVal loadFile1 As String) As Long

下面是完整的代码（frmDemCrc32.frm）：

VERSION 5.00
Begin VB.Form frmDemCrc32 
   Caption         =   "CRC32演示"
   ClientHeight    =   2790
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   8895
   BeginProperty Font 
      Name            =   "宋体"
      Size            =   9.75
      Charset         =   134
      Weight          =   400
      Underline       =   0   'False
      Italic          =   0   'False
      Strikethrough   =   0   'False
   EndProperty
   LinkTopic       =   "Form1"
   ScaleHeight     =   2790
   ScaleWidth      =   8895
   StartUpPosition =   2  'CenterScreen
   Begin VB.TextBox fcnPathTxt 
      Height          =   495
      Left            =   600
      TabIndex        =   7
      Text            =   "c:\s\datasb.fcn"
      Top             =   1320
      Width           =   3735
   End
   Begin VB.TextBox filePathTxt 
      Height          =   495
      Left            =   600
      TabIndex        =   6
      Text            =   "c:\s\datasb.txt"
      Top             =   360
      Width           =   3735
   End
   Begin VB.CommandButton cmdReadFCN 
      Caption         =   "读 FCN 文件"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   9
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   7440
      TabIndex        =   1
      Top             =   1320
      Width           =   1215
   End
   Begin VB.CommandButton cmdCal 
      Caption         =   "计算CRC32值"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   9
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   7440
      TabIndex        =   0
      Top             =   360
      Width           =   1215
   End
   Begin VB.Label Label2 
      Caption         =   "读取值："
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   9
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   4560
      TabIndex        =   5
      Top             =   1440
      Width           =   735
   End
   Begin VB.Label Label1 
      Caption         =   "计算值："
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   9
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   4560
      TabIndex        =   4
      Top             =   480
      Width           =   735
   End
   Begin VB.Label Label_read 
      ForeColor       =   &H80000001&
      Height          =   495
      Left            =   5640
      TabIndex        =   3
      Top             =   1440
      Width           =   1605
   End
   Begin VB.Label Label_cal 
      ForeColor       =   &H80000001&
      Height          =   495
      Left            =   5640
      TabIndex        =   2
      Top             =   480
      Width           =   1605
   End
End
Attribute VB_Name = "frmDemCrc32"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Private Declare Function calCRC32 Lib "FCN.dll" (ByVal filePath1 As String) As Long


Private Declare Function readFCN Lib "FCN.dll" (ByVal loadFile1 As String) As Long

Private Sub cmdCal_Click()
  '定义要计算的文件(具体路径和文件名称)
  Dim filePath1 As String
  filePath1 = filePathTxt.Text
  
  '调用函数
  Label_cal.Caption = calCRC32(filePath1)
  
End Sub

Private Sub cmdReadFCN_Click()
  '定义要读取的文件(具体路径和文件名称)
  Dim loadFile1 As String
  loadFile1 = fcnPathTxt.Text
  
  '调用函数
  Label_read.Caption = readFCN(loadFile1)
End Sub

附：

说明文件

文件接口

—CRC32动态库（FCN.DLL）

一、函数列表

函数名称	参数名称	数据类型	返回值	备注
calCRC32	filePath1	String	Long	计算文件的CRC32值
readFCN	loadFile1	String	Long	读取FCN文件的CRC32值

二、VB声明

1．计算文件的CRC32值

‘VB声明

PrivateDeclare Function calCRC32 Lib "FCN.dll" (ByVal filePath1 As String)As Long

2．读取FCN文件的CRC32值

‘VB声明

Private Declare Function readFCN Lib"FCN.dll" (ByVal loadFile1 As String) As Long

使用说明：（xiaobin）

请把MSVBVM60.DLL和FCN.dll与程序文件在一个目录里！

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