下面程序在运行时总是提示指针错误,请高人指点,谢谢
Dim Constr As String 'ODBC路径
Dim FileName As String '图片文件名
Const BLOCKSIZE = 4096 '每次读写块的大小
Dim ADOCon As New ADODB.Connection 'ADODB Connection对象
Dim ADORst As New ADODB.Recordset 'ADODB Recordset对象
Dim ADOFld As ADODB.Field 'ADODB Field对象Private Sub SaveToDB(ByRef Fld As ADODB.Field, DiskFile As String)
Dim byteData() As Byte '定义数据块数组
Dim NumBlocks As Long '定义数据块个数
Dim FileLength As Long '标识文件长度
Dim LeftOver As Long '定义剩余字节长度
Dim SourceFile As Long '定义自由文件号
Dim i As Long '定义循环变量
SourceFile = FreeFile '提供一个尚未使用的文件号
Open DiskFile For Binary Access Read As SourceFile '打开文件
FileLength = LOF(SourceFile) '得到文件长度
If FileLength = 0 Then
Close SourceFile
MsgBox DiskFile & "无内容或不存在!"
Else
NumBlocks = FileLength \ BLOCKSIZE '得到数据块的个数
LeftOver = FileLength Mod BLOCKSIZE '得到剩余字节数
Fld.Value = Null
ReDim byteDate(BLOCKSIZE) '重新定义数据块的大小
For i = 1 To NumBlocks
Get SourceFile, , byteData() '读到内存块中
Fld.AppendChunk byteData() '写如FLD
Next i
ReDim byteData(LeftOver) '重新定义数据块的大小
Get SourceFile, , byteData() '读到内存块中
Fld.AppendChunk byteData() '写入FLD
Close SourceFile '关闭源文件
End If
End SubPrivate Sub cmdPreView_Click()
'显示打开文件的公用对话框,选择需要加入数据库的图片
CommonDialog1.Filter = "图片文件|*.bmp;*.ico;*.jpg;*.gif;*.jpeg"
CommonDialog1.ShowOpen
FileName = CommonDialog1.FileName
PicBox.Picture = LoadPicture(FileName) '预览图片
End SubPrivate Sub cmdSave_Click()
ADORst.AddNew '新增记录
ADORst("Name").Value = txtAddName.Text '给动态集的第一个字段赋值
ADORst("ID").Value = txtAddID.Text '给动态集的第二个字段赋值
Set ADOFld = ADORst("Photo") '给ADODB.Field对象赋值
Call SaveToDB(ADOFld, FileName) '调用字程序,给第三个字段(image)赋值
ADORst.Update
End SubPrivate Sub cmdUpdate_Click()
'重新打开记录集,刷新记录
ADORst.Close
ADOCon.Close
Set ADORst = Nothing
Set ADOCon = Nothing
ADOCon.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "" & "\照片库.mdb;Persist Security Info=False"
ADORst.Open "select * from employee", ADOCon, adOpenDynamic, adLockOptimistic
Set Adodc1.Recordet = ADORst
End SubPrivate Sub Form_Load()
ADOCon.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "" & "\照片库.mdb;Persist Security Info=False"
ADORst.Open "select * from employee", ADOCon, adOpenDynamic, adLockOptimistic
'打开一个ADO动态集 表名为table
Set Adodc1.Recordset = ADORst '将动态集赋给ADO控件
End Sub
Private Sub Form_Unload(Cancel As Integer)
'记得关闭打开的数据库,释放资源
ADORst.Close
ADOCon.Close
Set ADORst = Nothing
Set ADOCon = Nothing
End Sub
Dim Constr As String 'ODBC路径
Dim FileName As String '图片文件名
Const BLOCKSIZE = 4096 '每次读写块的大小
Dim ADOCon As New ADODB.Connection 'ADODB Connection对象
Dim ADORst As New ADODB.Recordset 'ADODB Recordset对象
Dim ADOFld As ADODB.Field 'ADODB Field对象Private Sub SaveToDB(ByRef Fld As ADODB.Field, DiskFile As String)
Dim byteData() As Byte '定义数据块数组
Dim NumBlocks As Long '定义数据块个数
Dim FileLength As Long '标识文件长度
Dim LeftOver As Long '定义剩余字节长度
Dim SourceFile As Long '定义自由文件号
Dim i As Long '定义循环变量
SourceFile = FreeFile '提供一个尚未使用的文件号
Open DiskFile For Binary Access Read As SourceFile '打开文件
FileLength = LOF(SourceFile) '得到文件长度
If FileLength = 0 Then
Close SourceFile
MsgBox DiskFile & "无内容或不存在!"
Else
NumBlocks = FileLength \ BLOCKSIZE '得到数据块的个数
LeftOver = FileLength Mod BLOCKSIZE '得到剩余字节数
Fld.Value = Null
ReDim byteDate(BLOCKSIZE) '重新定义数据块的大小
For i = 1 To NumBlocks
Get SourceFile, , byteData() '读到内存块中
Fld.AppendChunk byteData() '写如FLD
Next i
ReDim byteData(LeftOver) '重新定义数据块的大小
Get SourceFile, , byteData() '读到内存块中
Fld.AppendChunk byteData() '写入FLD
Close SourceFile '关闭源文件
End If
End SubPrivate Sub cmdPreView_Click()
'显示打开文件的公用对话框,选择需要加入数据库的图片
CommonDialog1.Filter = "图片文件|*.bmp;*.ico;*.jpg;*.gif;*.jpeg"
CommonDialog1.ShowOpen
FileName = CommonDialog1.FileName
PicBox.Picture = LoadPicture(FileName) '预览图片
End SubPrivate Sub cmdSave_Click()
ADORst.AddNew '新增记录
ADORst("Name").Value = txtAddName.Text '给动态集的第一个字段赋值
ADORst("ID").Value = txtAddID.Text '给动态集的第二个字段赋值
Set ADOFld = ADORst("Photo") '给ADODB.Field对象赋值
Call SaveToDB(ADOFld, FileName) '调用字程序,给第三个字段(image)赋值
ADORst.Update
End SubPrivate Sub cmdUpdate_Click()
'重新打开记录集,刷新记录
ADORst.Close
ADOCon.Close
Set ADORst = Nothing
Set ADOCon = Nothing
ADOCon.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "" & "\照片库.mdb;Persist Security Info=False"
ADORst.Open "select * from employee", ADOCon, adOpenDynamic, adLockOptimistic
Set Adodc1.Recordet = ADORst
End SubPrivate Sub Form_Load()
ADOCon.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "" & "\照片库.mdb;Persist Security Info=False"
ADORst.Open "select * from employee", ADOCon, adOpenDynamic, adLockOptimistic
'打开一个ADO动态集 表名为table
Set Adodc1.Recordset = ADORst '将动态集赋给ADO控件
End Sub
Private Sub Form_Unload(Cancel As Integer)
'记得关闭打开的数据库,释放资源
ADORst.Close
ADOCon.Close
Set ADORst = Nothing
Set ADOCon = Nothing
End Sub
打开vb6,新建工程。添加两个按钮,一个image控件
注意:Access中的photo字段类型为OLE对象.
SqlServer中的photo字段类型为Image'** 引用 Microsoft ActiveX Data Objects 2.5 Library 及以上版本
‘2.5版本以下不支持Stream对象
Dim iConcstr As String
Dim iConc As ADODB.Connection
'保存文件到数据库中
Sub s_SaveFile()
Dim iStm As ADODB.Stream
Dim iRe As ADODB.Recordset
Dim iConcstr As String '读取文件到内容
Set iStm = New ADODB.Stream
With iStm
.Type = adTypeBinary '二进制模式
.Open
.LoadFromFile App.Path + "\test.jpg"
End With
'打开保存文件的表
Set iRe = New ADODB.Recordset
With iRe
.Open "select * from img", iConc, 1, 3
.AddNew '新增一条记录
.Fields("photo") = iStm.Read
.Update
End With
'完成后关闭对象
iRe.Close
iStm.Close
End Sub
Sub s_ReadFile()
Dim iStm As ADODB.Stream
Dim iRe As ADODB.Recordset
'打开表
Set iRe = New ADODB.Recordset
‘得到最新添加的纪录
iRe.Open "select top 1 * from img order by id desc", iConc, adOpenKeyset, adLockReadOnly
'保存到文件
Set iStm = New ADODB.Stream
With iStm
.Mode = adModeReadWrite
.Type = adTypeBinary
.Open
.Write iRe("photo")
‘这里注意了,如果当前目录下存在test1.jpg,会报一个文件写入失败的错误.
.SaveToFile App.Path & "\test1.jpg"
End With
Image1.Picture = LoadPicture(App.Path & "\test1.jpg")
'关闭对象
iRe.Close
iStm.Close
End Sub
Private Sub Command1_Click()
Call s_ReadFile
End Sub
Private Sub Command2_Click()
Call s_SaveFile
End Sub
Private Sub Form_Load()
'数据库连接字符串
iConcstr = "Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=False" & _
";Data Source=F:\csdn_vb\database\保存图片\access图片\img.mdb"‘下面的语句是连接sqlserver数据库的.
‘iConcstr = "Provider=SQLOLEDB.1;Persist Security Info=True;" & _
‘ "User ID=sa;Password=;Initial Catalog=test;Data Source=yang"
Set iConc = New ADODB.Connection
iConc.Open iConcstr
End Sub
Private Sub Form_Unload(Cancel As Integer)
iConc.Close
Set iConc = Nothing
End Sub