VB SQL数据库图片存取.doc

VB+SQL图片存取vb代码
VB窗体界面如下：

1.把图片写入到Field中函数代码：
PrivateSubpicsavetodb(ByReffldAsADODB.Field,diskfileAsString)
Constblocksize=4096
Dimbytedata()AsByte
DimnumblocksAsLong
DimfilelengthAsLong
DimleftoverAsLong
DimsourcefileAsLong
DimiAsLong
sourcefile=FreeFile
OpenTrim(CommonDialog1.filename)ForBinaryAccessReadAssourcefile
filelength=LOF(sourcefile)
Iffilelength=0Then
Closesourcefile
MsgBoxTrim(CommonDialog1.filename)&"无内容或不存在！"
Else
numblocks=filelength\blocksize
leftover=filelengthModblocksize
fld.Value=Null
ReDimbytedata(blocksize)
Fori=1Tonumblocks
Getsourcefile,,bytedata()
fld.AppendChunkbytedata()
Next
ReDimbytedata(leftover)
Getsourcefile,,bytedata()
fld.AppendChunkbytedata()
Closesourcefile
EndIf
EndSub
2.把图片存入SQL数据库XS（学生表）中：
PrivateSubCommand1_Click()
DimsAsString
Dimbytedata()AsByte
DimadofldAsADODB.Field
s="select*fromxswhere学号='"&Trim(Text1.Text)&"'"
sqlres.Opens,connectstring,adOpenDynamic,adLockPessimistic
IfNotsqlres.EOFThen
Setadofld=sqlres.Fields("照片")
IfCommonDialog1.filename<>""Then
Callpicsavetodb(adofld,"filename")
EndIf
sqlres.Update
3.把图片从SQL数据库读入VB图片框：
PrivateSubCommand3_Click()
DimsqlresAsADODB.Recordset
Setsqlres=NewADODB.Recordset
sqlres.Open"select*fromxswhere学号='"&Trim(Text1.Text)&"'",connectstring,adOpenDynamic,adLockPessimistic
DimstreamAsADODB.stream
Setstream=NewADODB.stream
stream.Mode=adModeReadWrite
'Image1.Picture=LoadPicture("")
IfNotIsNull(sqlres.Fields("照片"))Then
stream.Type=adTypeBinary
stream.Open
stream.Writesqlres.Fields("照片")
stream.SaveToFile"filename",adSaveCreateOverWrite
Image1.Picture=LoadPicture("filename")
sqlres.Close
stream.Close
EndIf
EndSub
4修改图片：
PrivateSubCommand2_Click()
DimfilenameAsString
CommonDialog1.Filter="图像(*.jpg)|*.jpg|位图(*.bmp)|*.bmp"
CommonDialog1.InitDir=App.Path&"\图片库"
CommonDialog1.ShowOpen
filename=CommonDialog1.filename
Image1.Picture=LoadPicture(filename)
EndSub