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很多兄弟在这里问关于VB6读写数据库中的图片的问题，在此有一例，希有所启发。 1，以人名和相关图片为例说明，数据库为Access，有如下字段：Name char,picture OLE object,FileLength Number。当为ms sql时，将picture改为lob即可。 2，示例包含control：commom dialog,picture,listbox。 源码如下： Option Explicit Private Declare Function GetTempFileName Lib "kernel32" Alias "GetTempFileNameA" (ByVal lpszPath As String, ByVal lpPrefixString As String, ByVal wUnique As Long, ByVal lpTempFileName As String) As Long Private Declare Function GetTempPath Lib "kernel32" Alias "GetTempPathA" (ByVal nBufferLength As Long, ByVal lpBuffer As String) As Long Private Const MAX_PATH = 260 Private m_DBConn As ADODB.Connection Private Const BLOCK_SIZE = 10000 \\\' Return a temporary file name. Private Function TemporaryFileName() As String Dim temp_path As String Dim temp_file As String Dim length As Long \\\' Get the temporary file path. temp_path = Space$(MAX_PATH) length = GetTempPath(MAX_PATH, temp_path) temp_path = Left$(temp_path, length) \\\' Get the file name. temp_file = Space$(MAX_PATH) GetTempFileName temp_path, "per", 0, temp_file TemporaryFileName = Left$(temp_file, InStr(temp_file, Chr$(0)) - 1) End Function Private Sub Form_Load() Dim db_file As String Dim rs As ADODB.Recordset \\\' Get the database file name. db_file = App.Path If Right$(db_file, 1) <> "" Then db_file = db_file & "" db_file = db_file & "dbpict.mdb" \\\' Open the database connection. Set m_DBConn = New ADODB.Connection m_DBConn.Open _ "Provider=Microsoft.Jet.OLEDB.4.0;" & _ "Data Source=" & db_file & ";" & _ "Persist Security Info=False" \\\' Get the list of people. Set rs = m_DBConn.Execute("SELECT Name FROM People ORDER BY Name", , adCmdText) Do While Not rs.EOF lstPeople.AddItem rs!Name rs.MoveNext Loop rs.Close Set rs = Nothing End Sub Private Sub Form_Resize() lstPeople.Height = ScaleHeight End Sub \\\' Display the clicked person. Private Sub lstPeople_Click() Dim rs As ADODB.Recordset Dim bytes() As Byte Dim file_name As String Dim file_num As Integer Dim file_length As Long Dim num_blocks As Long Dim left_over As Long Dim block_num As Long Dim hgt As Single picPerson.Visible = False Screen.MousePointer = vbHourglass DoEvents \\\' Get the record. Set rs = m_DBConn.Execute("SELECT * FROM People WHERE Name=\\\'" & _ lstPeople.Text & "\\\'", , adCmdText) If rs.EOF Then Exit Sub \\\' Get a temporary file name. file_name = TemporaryFileName() \\\' Open the file. file_num = FreeFile Open file_name For Binary As #file_num \\\' Copy the data into the file. file_length = rs!FileLength num_blocks = file_length / BLOCK_SIZE left_over = file_length Mod BLOCK_SIZE For block_num = 1 To num_blocks bytes() = rs!Picture.GetChunk(BLOCK_SIZE) Put #file_num, , bytes() Next block_num If left_over > 0 Then bytes() = rs!Picture.GetChunk(left_over) Put #file_num, , bytes() End If Close #file_num \\\' Display the picture file. picPerson.Picture = LoadPicture(file_name) picPerson.Visible = True Width = picPerson.Left + picPerson.Width + Width - ScaleWidth hgt = picPerson.Top + picPerson.Height + Height - ScaleHeight If hgt < 1440 Then hgt = 1440 Height = hgt Kill file_name Screen.MousePointer = vbDefault End Sub Private Sub mnuRecordAdd_Click() Dim rs As ADODB.Recordset Dim person_name As String Dim file_num As String Dim file_length As String Dim bytes() As Byte Dim num_blocks As Long Dim left_over As Long Dim block_num As Long person_name = InputBox("Name") If Len(person_name) = 0 Then Exit Sub dlgPicture.Flags = _ cdlOFNFileMustExist Or _ cdlOFNHideReadOnly Or _ cdlOFNExplorer dlgPicture.CancelError = True dlgPicture.Filter = "Graphics Files|*.bmp;*.ico;*.jpg;*.gif" On Error Resume Next dlgPicture.ShowOpen If Err.Number = cdlCancel Then Exit Sub ElseIf Err.Number <> 0 Then MsgBox "Error " & Format$(Err.Number) & _ " selecting file." & vbCrLf & Err.Description Exit Sub End If \\\' Open the picture file. file_num = FreeFile Open dlgPicture.FileName For Binary Access Read As #file_num file_length = LOF(file_num) If file_length > 0 Then num_blocks = file_length / BLOCK_SIZE left_over = file_length Mod BLOCK_SIZE Set rs = New ADODB.Recordset rs.CursorType = adOpenKeyset rs.LockType = adLockOptimistic rs.Open "Select Name, Picture, FileLength FROM People", m_DBConn rs.AddNew rs!Name = person_name rs!FileLength = file_length ReDim bytes(BLOCK_SIZE) For block_num = 1 To num_blocks Get #file_num, , bytes() rs!Picture.AppendChunk bytes() Next block_num If left_over > 0 Then ReDim bytes(left_over) Get #file_num, , bytes() rs!Picture.AppendChunk bytes() End If rs.Update Close #file_num lstPeople.AddItem person_name lstPeople.Text = person_name End If End Sub 返回类别: 教程 上一教程: ADO如何建立修改?除资料表呢(BIG5) 下一教程: 利用ASP打造个性化论坛(中) 您可以阅读与"用VB6读写数据库中的图片"相关的教程: · 如何把存储在数据库中的图片根据自己的需要的大小显示出来 · 如何准确显示数据库中的图片 · 关于图片与文本同存在数据库中的详细思路 · 用纯ASP代码实现图片上传并存入数据库中(二) · 让数据库中的记录用上一条下一条显示 |
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