image读取数据中的图片问题

[shepengtao]

请教：我想在image中装载一副图片后，用
stream:=TMemoryStream.Create;
img.Picture.Graphic.SaveToStream(stream);
TBlobField(adoq1.FieldByName('Pic')).LoadFromStream(stream);
存入数据库中，
然后 stream := TMemorystream.Create;
try
TBlobField(adoq1.FieldByName('pic')).SaveToStream(stream);
stream.Position:=0;
frm_photo.img1.Picture.Graphic.LoadFromStream(stream);
finally
stream.Free;
end;
再从数据中显示图片，怎么老是抱地址访问错误？请教！！

[tiankj]

stream:=TMemoryStream.Create;
img.Picture.Graphic.SaveToStream(stream);
TBlobField(adoq1.FieldByName('Pic')).LoadFromStream(stream);
freeandnil(stream);//
存入数据库中，

然后 stream := TMemorystream.Create;
try
TBlobField(adoq1.FieldByName('pic')).SaveToStream(stream);
stream.Position:=0;
frm_photo.img1.Picture.Graphic.LoadFromStream(stream);
finally
stream.Free;
end;

[shepengtao]

不是这样的，我这两段代码是在两个地方写的

[richard_ouyang]

你是不是什么东西没有创建就在使用了。请查找一下。

[ss__328]

function TjpgPic.LoadFromDB(TypeID: string): boolean;
var MS: TMemoryStream;
cdsPic: TClientDataSet;
SQLStr:string;
begin
cdsPic := TClientDataSet.Create(Application);
with cdsPic do
begin
SQLStr := 'Select * from ' + FGraphTableName + ' Where ' +
FTypeFieldName
+ '=''' + TypeID + '''';
OpenSQL(SQLStr,cdsPic);
MS := TMemoryStream.Create;
try
if not Eof then
begin
if TBlobField(FieldByName(FGraphFieldName)).IsNull then
Exit;

TBlobField(FieldByName(FGraphFieldName)).SaveToStream(MS);
MS.Position := 0;
FjpgPic.LoadFromStream(MS);
GraphExisted := true;
Result := true
end else
begin
Result := False;
GraphExisted := false;
end;
finally
Ms.free;
end;
end;
end;

[ss__328]

刚写的代码， 正确的，你自己检查下

function TjpgPic.SaveToDB(TypeID: string): boolean;
var MS: TMemoryStream;
cdsPic: TClientDataSet;
SQLStr:string;
begin
if not GraphExisted then
Exit;
cdsPic := TClientDataSet.Create(Application);
with cdsPic do
begin
SQLStr := 'Select * from ' + FGraphTableName + ' Where ' +
FTypeFieldName + '=''' + TypeID + '''';
OpenSQL(SQLStr,cdsPic);
if not Eof then
Edit
else
begin
Insert;
FieldByName(FTypeFieldName).AsString := TypeID;
end;
MS := TMemoryStream.Create;
try
FjpgPic.SaveToStream(MS);
TBlobField(FieldByName(FGraphFieldName)).LoadFromStream(MS);
finally
Ms.free;
end;
Post;
ApplyUpdates(-1);
end;
Result := true;
end;

[caiso]

顶一下@@