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。
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
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
| 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！