来帮帮我!!图像存取的问题??? ( 积分: 50 )

请问 如像将图形显示控件(如:image,picture控件等)中的图片保存到sql server数据库中的image字段中,

又是如何从image字段中请出图像,并显示在图形显示控件中

请高手帮忙

请问 如像将图形显示控件(如:image,picture控件等)中的图片保存到sql server数据库中的image字段中,

又是如何从image字段中请出图像,并显示在图形显示控件中

请高手帮忙

先打开图片：
procedure TForm1.Button3Click(Sender: TObject);
var
tmp:TMemoryStream;
begin
tmp:=TMemoryStream.Create;
if OpenPictureDialog1.Execute then
begin
sFileName:=OpenPictureDialog1.FileName; //sFileName是全局变量
Image1.Picture.LoadFromFile(sFileName);
end;
Image1.Picture.Graphic.SaveToStream(tmp);
end;

图片保存：
procedure TForm1.Button2Click(Sender: TObject);
var
tmp:TMemoryStream;
begin
tmp:=TMemoryStream.Create;
if sFileName='' then
begin
application.MessageBox('先选择图像','提示',MB_OK);
exit;
end;
image1.Picture.Graphic.SaveToStream(tmp);
Query1.ParamByName('xm').AsString:='图片内容';
Query1.ParamByName('Pic').LoadFromStream(tmp,ftBlob);
Query1.ExecSQL;
end;
//读取过程
procedure TForm1.Button2Click(Sender: TObject);
var
mStream:TMemoryStream;
JpgFile:TjpegImage;
begin
if not ADOQuery1.FieldByName('photo').IsNull then begin ;
mStream:=TMemoryStream.Create ;
JpgFile:=TjpegImage.Create ;
TBlobField(ADOQuery1.FieldByName('photo')).SaveToStream(mStream);　　//顯示的轉換為BlobFiled並保存至內存流
mStream.Position :=0;
jpgfile.LoadFromStream(MStream); //主要就是这一句
image2.Picture.Assign(JpgFile);
end
else begin
image2.Picture :=nil;
end;
end;

aricyoung的回答已经实现了你的要求,不过aricyoung很多地方的TMemoryStream没有释放.

释放一下

从SQL Server存取JPEG文件


近日笔者书写一个小型的学生管理系统时，需要用到ADO控件存取SQL Server数据库图片，查看资料发现基本都是针对BMP文件进行操作(巨增数据库大小)，但发现了★eagletian★高手翻译的ADO英文技术文档，里面涉及到了数据库存取JPEG文件的关键技术，在win98+sql server桌面版中测试通过，运行良好，现于源码公开如下：
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
ExtCtrls, DBCtrls, Grids, DBGrids, Db, ADODB,jpeg, StdCtrls,dbtables;
{一定要USES JPEG单元,使能存储JPG文件格式}
type
TForm1 = class(TForm)
DataSource1: TDataSource;
ADOQuery1: TADOQuery;
DBGrid1: TDBGrid;
DBNavigator1: TDBNavigator;
Image1: TImage;
savebutton: TButton;
showbutton: TButton;
OpenDialog1: TOpenDialog;
ADOQuery1id: TIntegerField;
ADOQuery1pic: TBlobField;
procedure savebuttonClick(Sender: TObject);
procedure showbuttonClick(Sender: TObject);
procedure DBNavigator1Click(Sender: TObject; Button: TNavigateBtn);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

function JpegStartsInBlob(PicField:TBlobField):integer;
var
ghy: TADOBlobstream;
buffer:Word;
hx: string;
begin
Result := -1;
ghy := TADOBlobstream.Create(PicField, bmRead);
try
while (Result = -1) and (ghy.Position + 1 < ghy.Size) do
begin
ghy.ReadBuffer(buffer, 1);
hx:=IntToHex(buffer, 2);
if hx = ’FF’ then begin
ghy.ReadBuffer(buffer, 1);
hx:=IntToHex(buffer, 2);
if hx = ’D8’ then Result := ghy.Position - 2
else if hx = ’FF’ then
ghy.Position := ghy.Position-1;
end; //if
end; //while
finally
ghy.Free
end; //try
end;


procedure TForm1.savebuttonClick(Sender: TObject);
var
picstream:tadoblobstream;
begin
adoquery1.edit;
picstream:=tadoblobstream.Create(tblobfield(adoquery1.fields[1]),bmWrite);
if form1.opendialog1.execute then
begin
picstream.LoadFromFile(opendialog1.filename);
picstream.Position:=0;
adoquery1.edit;
tblobfield(adoquery1.Fields[1]).loadfromstream(picstream);
adoquery1.post;
end;


end;

procedure TForm1.showbuttonClick(Sender: TObject);
var
ghy:TADOBlobstream;
pic:tjpegimage;
begin
ghy := TADOBlobstream.Create(Adoquery1pic, bmRead);
try
ghy.Seek(JpegStartsInBlob(Adoquery1pic),soFromBeginning);
Pic:=TJpegImage.Create;
try
Pic.LoadFromStream(ghy);
Image1.Picture.Graphic:=Pic;
finally
Pic.Free;
end;
finally
ghy.Free
end;
end;

procedure TForm1.DBNavigator1Click(Sender: TObject; Button: TNavigateBtn);
begin
if button in [nbFirst, nbPrior, nbNext, nbLast] then showbutton.Click;
end;

end.

如果数据库中要存储的是BMP文件，则在procedure TForm1.showbuttonClick(Sender: TObject);过程中代码更改如下即可存储显示BMP文件格式的操作。
procedure TForm1.showbuttonClick(Sender: TObject);
var
ghy:TADOBlobstream;
pic:tbitmap;
begin
ghy := TADOBlobstream.Create(Adoquery1pic, bmRead);
try
{ ghy.Seek(JpegStartsInBlob(Adoquery1pic),soFromBeginning);}
Pic:=Tbitmap.Create;
try
Pic.LoadFromStream(ghy);
Image1.Picture.Graphic:=Pic;
finally
Pic.Free;
end;
finally
ghy.Free
end;
end;
　　到此用DELPHI存取JPEG文件到SQL Server数据库中的具体操作已经叙述完毕。

1.请确保你的JPEG是标准格式
2.试试下面的方法
http://www.delphibbs.com/delphibbs/dispq.asp?lid=3130524

多人接受答案了。