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實戰VisualBasic條形碼編程


一、條形碼的讀取

用過鍵盤口式的掃條碼工具的朋友就知道,它就如同在鍵盤上按下數字鍵一樣,基本不需任何編程和處理。但如果你使用的是其它接口的話,可能你就要為該設備編寫通訊代碼了。以下有一段簡單的25針串口的條碼讀取器通訊代碼。

Option Explicit
Dim sData As String
Private Sub Form_Load()
With MSComm1
.CommPort = 3 '設為COM3,試運行的系統而定,你可提供一個Combox讓用戶選擇。
.PortOpen = True'打開通訊端口
End With
End Sub

Private Sub MSComm1_OnComm()

Dim EndPos As Integer
Select Case MSComm1.CommEvent
Case comEvReceive '當有數據傳送過來時
sData = sData & Trim(MSComm1.Input)
'檢索回車,通常讀卡機每組數據結尾都返回一個回車作為結束符
EndPos = InStr(1, sData, Chr(13))
If EndPos = 0 Then '如果未結束就繼續努力
Else '讀完一組。
lblBarCode.Caption = sData '顯示一組條形碼
With lstBarCode
.AddItem Mid(sData, 1, EndPos - 1) '添加一組條形碼到列表
End With
sData = "" '清空
End If
End Select
End Sub


Private Sub cmdEnd_Click()
MSComm1.PortOpen = False '關閉端口
End
End Sub

二、條形碼的生成

看完以上關于條碼讀取的代碼是否覺得很容易呢?對,在VB上編程本來就不難。以下關于條形碼生成的代碼也是很容易理解,只需使用一個OFFICE的附帶的BarCode控件就可以輕松打印出11種不同標準的條形碼,足以滿足我們的要求。想起我書架上的一本書中的一篇用Turbo C編寫條形碼打印程序文章,長篇大論,那時不知看了n天,打了n小時字結果也不盡人意,現在真是幸福多了:)。廢話說完,得回歸正題。且看條形碼生成的代碼及有關說明。

源代碼主要由兩個窗體(frmMain主窗體和frmOption條碼設置窗體)和兩個模塊組成(modGetScreen.bas、SysDLG32.bas)。考慮到篇幅,這里只列出部分較為關鍵的代碼。
新建一個標準工程,添加一個名為(Microsoft Access BarCode Control9)的條形碼部件,并添加一個條碼控件到窗口,并將窗口改名為frmMain,如圖所示。由于控件比較多,這里不便細說,詳細內容請看源代碼。
模塊modGetScreen.bas代碼如下:

Option Explicit

'聲明BitBlt、GetDesktopWindow、GetWindowDC、ReleaseDC這幾個API函數略

Public RegUser As Boolean


Sub GetObjImage1(Obj As Object, OwnerForm As PictureBox, Picture1 As PictureBox)
'hDC
Dim hWndDesk As Long
Dim hDCDesk As Long
'區域表達變量
Dim x As Long
Dim y As Long
Dim w As Long
Dim h As Long


x = Obj.Left Screen.TwipsPerPixelX
y = Obj.Top Screen.TwipsPerPixelY
w = Obj.Width Screen.TwipsPerPixelX
h = Obj.Height Screen.TwipsPerPixelY
hDCDesk = OwnerForm.hdc
'取出圖像
Call BitBlt(Picture1.hdc, 0, 0, w, h, hDCDesk, x, y, vbSrcCopy)
Call ReleaseDC(hWndDesk, hDCDesk)

End Sub

主窗體frmMain.frm部分代碼如下:

Private Sub cmdPrint_Click()
'生成條形碼圖像
Dim r As Long, i As Integer, t As String,cfile As String '臨時變量
t = BarCode
For i = 0 To Val(Times) - 1

BarCode1.Value = BarCode + i
DoEvents
Picture1.Refresh

GetObjImage1 BarCode1, Conel, Picture1

If RegUser = False Then '如果未注冊添加MASK標記
Picture1.PaintPicture Picture2.Picture, 300, 300
End If

If Dir(SavePath, vbDirectory) = "" Then MkDir SavePath

SavePath = SavePath & IIf(Right(SavePath, 1) <> "", "", "")

cfile = SavePath & BarCode1.Value & ".bmp"

SavePicture Picture1.Image, cfile '將條形碼保存為圖像文件以便打印
Next
BarCode = t

End Sub

條形碼設置窗體frmOption.frm代碼如下:

Option Explicit
'條形碼設置模塊

Private Sub cboBig_Click()
BarCode1.Style = cboBig.ListIndex '改變標準
End Sub

Private Sub cboDirection_Click()
BarCode1.Direction = cboDirection.ListIndex '改變方向
End Sub

Private Sub cboLine_Click()
BarCode1.LineWeight = cboLine.ListIndex '改變線寬
End Sub

Private Sub cboSmall_Click()
BarCode1.SubStyle = cboSmall.ListIndex '改變樣式
End Sub

Private Sub Check1_Click()
BarCode1.ShowData = Check1.Value '是否顯示數據
End Sub

Private Sub cmdChange_Click()
'設置長、寬大小
BarWidth = BarCode1.Height
BarHeight = BarCode1.Width
cmdRefresh_Click
End Sub

Private Sub cmdOK_Click()
'傳送條形碼設定到主界面
With frmMain.BarCode1
.LineWeight = BarCode1.LineWeight
.Style = BarCode1.Style
.SubStyle = BarCode1.SubStyle
.Direction = BarCode1.Direction
.Width = BarCode1.Width
.Height = BarCode1.Height
.ShowData = BarCode1.ShowData
Me.Hide
End With
With frmMain
.Picture1.Width = .BarCode1.Width
.Picture1.Height = .BarCode1.Height
.Conel.Width = .BarCode1.Width
.Conel.Height = .BarCode1.Height
End With
End Sub

Private Sub cmdRefresh_Click()
BarCode1.Width = BarWidth
BarCode1.Height = BarHeight
End Sub

Private Sub Form_Load()
LoadBarInfo
BarWidth = BarCode1.Width
BarHeight = BarCode1.Height
End Sub

Sub LoadBarInfo() '初始化選項
LoadBigClass cboBig
LoadSmallClass cboSmall
LoadLineSize cboLine
LoadDirection cboDirection
End Sub
Sub LoadBigClass(cbo As ComboBox) '條碼標準
With cbo
.AddItem "UPC-A"
.AddItem "UPC-E"
.AddItem "EAN-13"
.AddItem "EAN-8"
.AddItem "Case Code"
.AddItem "Codabar (NW-T)"
.AddItem "Code-39"
.AddItem "Code-128"
.AddItem "U.S. Postnet"
.AddItem "U.S. Postal FIM"
.AddItem "JP Post"
.ListIndex = 2
End With
End Sub
Sub LoadSmallClass(cbo As ComboBox) '條碼樣式
With cbo
.AddItem "Standard"
.AddItem "2-Digit Supplement"
.AddItem "5-Digit Supplement"
.AddItem "POS Case Code"
.ListIndex = 0
End With
End Sub

 

作者:http://www.zhujiangroad.com
來源:http://www.zhujiangroad.com
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