frmreturn.frm

<Visual Basic 数据库开发实例精粹（第二版）>一书首先介绍了Visual Basic(简称VB)开发的技巧和重点技术

VERSION 5.00
Begin VB.Form FrmReturn 
   BorderStyle     =   1  'Fixed Single
   Caption         =   "图书归还"
   ClientHeight    =   2055
   ClientLeft      =   45
   ClientTop       =   360
   ClientWidth     =   4320
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MDIChild        =   -1  'True
   ScaleHeight     =   2055
   ScaleWidth      =   4320
   Begin VB.TextBox TextRtBkNum 
      Height          =   375
      Left            =   1560
      MultiLine       =   -1  'True
      TabIndex        =   2
      Top             =   1080
      Width           =   2655
   End
   Begin VB.CommandButton CmdReturn 
      Caption         =   "确定"
      Height          =   375
      Left            =   1680
      TabIndex        =   1
      Top             =   1560
      Width           =   1095
   End
   Begin VB.CommandButton CmdCancel 
      Cancel          =   -1  'True
      Caption         =   "取消"
      Height          =   375
      Left            =   3120
      TabIndex        =   0
      Top             =   1560
      Width           =   1095
   End
   Begin VB.Label Label1 
      Caption         =   "请手动输入或通过读卡器读入需要归还的图书号："
      BeginProperty Font 
         Name            =   "楷体_GB2312"
         Size            =   12
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      ForeColor       =   &H00FF0000&
      Height          =   615
      Left            =   360
      TabIndex        =   4
      Top             =   240
      Width           =   3495
   End
   Begin VB.Label Label2 
      Caption         =   "图书号："
      BeginProperty Font 
         Name            =   "楷体_GB2312"
         Size            =   12
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      ForeColor       =   &H00FF0000&
      Height          =   375
      Left            =   360
      TabIndex        =   3
      Top             =   1080
      Width           =   1455
   End
End
Attribute VB_Name = "FrmReturn"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub CmdCancel_Click()   '取消
    Unload Me
End Sub

'归还图书
Private Sub CmdReturn_Click()
Dim str As String
    
    '检验输入内容
    If Len(Trim(Me.TextRtBkNum.Text)) <= 0 Then
        MsgBox "请输入图书号！"
        Exit Sub
    ElseIf Len(Trim(Me.TextRtBkNum.Text)) > 8 Then
        MsgBox "您输入的书号过长！"
        Exit Sub
    ElseIf Val(Me.TextRtBkNum.Text) = 0 Then
        MsgBox "书号必须为整数且不能为0！"
        Exit Sub
    End If
    
    '生成要发送的数据 = Return， Rec_BkNum
    str = "Return," & Trim(Me.TextRtBkNum.Text)
    '检验sock连接并向服务器发送数据
    If MDIFrm.SockToSvr.State <> sckConnected Then
        MsgBox "还没有连接数据库，不能发送请求！"
        Exit Sub
    End If
    MDIFrm.SockToSvr.SendData str
    Unload Me

End Sub