利用Vb保存一幅图到Access数据库-

1、在我们做的许多管理系统中,除了保存大量的文字信息以外,有时候也需要保存一定数量的图片。例如:一个人事管理系统,就需要对每个人的照片进行保存,以便可以方便的对每个人的信息进行处理。Office中的Access数据库除了保存文本,还可以保存图片,保存图片的数据类型就是"OLE对象":它用来保存 Excel 电子表格、 Word 文档、图形、声音或其他二进制数据。我现在用一个例子介绍利用vb保存图片的方法,首先我们要介绍vb中处理二进制数据的语句:Put、Get。Put、Get语句语法如下:Put # filenumber,recnumber,varnameGet # filen

2、umber,recnumber,varnameFilenumber :必需的。任何有效的文件号Recnumber :可选的。Variant(Long。记录号(Random方式的文件或字节数(Binary 方式的文件,指明在此处开始写入Varname :必需的。包含要写入磁盘的数据的变量名说明:文件中的第一个记录或字节位于位置1,第二个记录或字节位于位置2,依次类推。若省略recnumber,则将上一个Get或Put语句之后的下一个记录或字节写入。所有用于分界的逗号都必须罗列出来。现在我们来开始建一个工程,功能是保存一个文档,同时可以保存一幅图片。首先我们建一个表(表名为photo,字段如下:字

3、段名类型标题class 类别文档的分类photo OLE对象保存图片文件photo_ext 文本图片的扩展名inputtime 日期/时间文档输入的时间modifytime 日期/时间文档的修改时间subject 文本文本现在我们就可以创建finput窗口文件来保存图片。首先我们要连接我们的数据库,代码如下:Dim cnstr As Stringamp; "Data Source=" amp; App.Path amp; "realize.mdb;Jet OLEDB:database "cn.Open cnstrcn.CursorLocation = a

4、dUseClient这段代码可以放在form_load事件中,当做一个多窗口的系统时,最好放到一个模块文件中,这样在其它窗口中都可以调用这个cn连接。下面是具体的窗口代码:VERSION 5.00Object= "F9043C88-F6F2-101A-A3C9-08002B2F49FB#1.2#0" "comdlg32.ocx"Object= "3B7C8863-D78F-101B-B9B5-04021C009402#1.2#0" "richtx32.ocx"Begin VB.Form finputBorderSt

5、yle = 0 'NoneCaption = "文档输入"ClientHeight = 6240ClientLeft = 0ClientTop = 0ClientWidth = 8955ControlBox = 0 'FalseLinkTopic = "Form1"MDIChild = -1 'TrueScaleHeight = 6240ScaleWidth = 8955ShowInTaskbar = 0 'FalseBegin MSComDlg.CommonDialog CommonDialog1 Left = 8040

6、Top = 3840_ExtentX = 847_ExtentY = 847_Version = 393216EndBegin VB.ComboBox Combo1Height = 300Left = 7080TabIndex = 10Top = 480EndBegin VB.CommandButton Command3 Caption = "关闭"Height = 375Left = 5280TabIndex = 8Top = 5640Width = 1095EndBegin VB.CommandButton Command2 Caption = "保存&quo

7、t;Height = 375Left = 2520TabIndex = 7Top = 5640Width = 1095EndBegin VB.CommandButton Command1 Caption = "浏览"Height = 255Left = 8040Top = 4800Width = 735EndBegin VB.TextBox Text2Height = 375Left = 1200TabIndex = 5Top = 4800Width = 6375EndBegin RichTextLib.RichTextBox RichTextBox1 Height = 3

8、615Left = 1200TabIndex = 3Top = 960Width = 6375_ExtentX = 11245_ExtentY = 6376_Version = 393217Enabled = -1 'TrueTextRTF = $"finput.frx":0000EndBegin VB.TextBox Text1 Height = 375Left = 1200TabIndex = 2Top = 443Width = 4695EndBegin VB.Label Label4 Caption = "类别" Height = 255L

9、eft = 6240TabIndex = 9Top = 480Width = 615EndBegin VB.Label Label3 Caption = "图片" Height = 255Left = 480TabIndex = 4Top = 4800Width = 495EndBegin VB.Label Label2Caption = "内容"Height = 255Left = 480TabIndex = 1Top = 960Width = 495EndBegin VB.Label Label1Caption = "标题"Hei

10、ght = 255Left = 480TabIndex = 0Top = 503Width = 495EndEndAttribute VB_Name = "finput" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = FalseAttribute VB_PredeclaredId = TrueAttribute VB_Exposed = FalseOption ExplicitPrivate Sub Command1_Click(CommonDialog1.DefaultExt = App.Pat

11、hCommonDialog1.Filter = "Pictures (*.bmp;*.jpg;*.gif *.bmp;*.jpg;*.gif" '注意要加引号CommonDialog1.ShowOpenText2.Text = CommonDialog1.FileNameEnd Sub'保存文档的标题,和文档的内容,以及相应的图片Private Sub Command2_Click('判断是否所写的文档是否已经存在数据库了,如果没有,则保存,否则'不能保存(利用一个"临时rs"查询标题Dim subject, sql As

12、 StringDim temp_photo As StreamDim rs As New ADODB.RecordsetDim rs1 As New ADODB.Recordset '定义rs1得到类别的idDim class_id As Integer '定义得到类别的ID号subject = Trim(Text1.Text '获得标题sql = "select * from paper where subject='" + subject + "'"'开始查询rs.Open sql, cn, adOpe

13、nDynamic, adLockPessimistic'判断标题是否存在If rs.EOF Then '文档不存在,开始保存Dim tempdate As Date '临时时间变量tempdate = Daters.AddNew'得到类别的IDsql = "select cl_number,class from class where class='" + Combo1.Text + "'" rs1.Open sql, cn, adOpenDynamic, adLockPessimisticrs("

14、;class" = rs1("cl_number"rs1.Close '关闭rs1rs("subject" = subjectrs("content" = RichTextBox1.TextIf Trim(Text2.Text <> "" Then '假如有图片,开始得到图片文件Dim image_data( As Byte '定义图片保存的变量Open Trim(Text2.Text For Binary As #1ReDim image_data(LOF(1 - 1

15、Get #1, , image_data(rs("photo".AppendChunk image_data(End Ifrs("inputtime" = tempdaters("modifytime" = tempdaters.Update '可能出现保存不成功的现象,所以要考虑可能会出现错误MsgBox ("保存成功!" '保存成功Text1.Text = ""RichTextBox1.Text = ""Text2.Text = ""

16、'此处清空选择图片的框Else '存在,不能保存,显示错误信息MsgBox ("文档已经存在,不能保存,请修改!"End Ifrs.Close '关闭结果集End SubPrivate Sub Command3_Click(Unload MeEnd SubPrivate Sub Form_Load(Me.Left = 0Me.Top = 0fmain.Width = Me.Width + 340fmain.Height = Me.Height + 1550'显示文档的类别Dim rs As New ADODB.RecordsetDim sql

17、 As Stringsql = "select * from class"rs.Open sql, cn, 1, 1Do While Not rs.EOF '类别不空,则添加进去,对应类别的number为索引Combo1.AddItem rs("class"rs.MoveNextLoopIf rs.RecordCount <> 0 Then '只有查询结果集不为空时,才能设定显示第一项,利用纪录总数不为0判定Combo1.ListIndex = 0 '不能用not rs.eof判定,因为现在cursor已经到了最后En

18、d Ifrs.CloseEnd Sub当然,在上面这段代码中,还用到了另一个表(表名为class,字段如下:字段名类型意义class 文本文档类别的名称cl_number 数字类别的编号上面的代码可以较好的保存我们的文档和图片,我们还需要显示我们的图片和文档,现在我们还要显示我们的图片,我做了一个显示窗口(fshow,现在我假设数据库中有一条记录,subject为"ipx协议简介",里面有一个图片(ipx体系结构,窗口代码如下:VERSION 5.00Object = "831FDD16-0C5C-11D2-A9FC-0000F8754DA1#2.0#0"

19、; "mscomctl.ocx"Object = "3B7C8863-D78F-101B-B9B5-04021C009402#1.2#0" "richtx32.ocx"Begin VB.Form fshowBorderStyle = 0 'NoneCaption = "显示图片"ClientHeight = 7125ClientLeft = 0ClientTop = 0ClientWidth = 10275LinkTopic = "Form1"MDIChild = -1 'Tru

20、eScaleHeight = 7125ScaleWidth = 10275ShowInTaskbar = 0 'FalseBegin VB.Frame Frame2Height = 6615Left = 2880TabIndex = 1Top = 240Width = 7335Begin VB.CommandButton Command1Caption = "关闭"Height = 375Left = 5880TabIndex = 5Top = 5880Width = 1215EndBegin RichTextLib.RichTextBox RichTextBox1

21、 Height = 4095Left = 120TabIndex = 4Width = 6975_ExtentX = 12303_ExtentY = 7223_Version = 393217TextRTF = $"fshow.frx":0000 EndBegin VB.Image Image1 Height = 855Left = 120Stretch = -1 'TrueTop = 5640Width = 1095EndBegin VB.Line Line4X1 = 5520X2 = 5520Y1 = 5520Y2 = 6600EndBegin VB.Line

22、Line3X1 = 0Y1 = 5520Y2 = 5520EndBegin VB.Line Line2X1 = 0X2 = 7320Y1 = 960Y2 = 960EndBegin VB.Label Label1 BackColor = amp;H80000009amp; Height = 615Left = 120TabIndex = 3Top = 240Width = 7095EndEndBegin VB.Frame Frame1Height = 6735Left = 120TabIndex = 0 Top = 240 Width = 2535 Begin MSComctlLib.Tree

23、View TreeView1 Height = 6375 Left = 120 TabIndex = 2 Top = 240 Width = 2295 _ExtentX = 4048 _ExtentY = 11245 _Version = 393217 PathSeparator = "" Style = 7 Appearance = 1 End End Begin VB.Line Line1 BorderColor = amp;H80000001amp; X1 = 2760 X2 = 2760 Y1 = 120 Y2 = 6960 End End Attribute VB

24、_Name = "fshow" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Option Explicit Private Sub Command1_Click( Unload Me End Sub Private Sub Form_Load( Dim temptop, templeft As Long Me.Left = 0 Me.Top = 0 fmain.Width = Me.Width + 340 fmain.Height = Me