delphi 用DBExpress处理JPG图片

数据库是SQL Server 2005，字段类型为Image。

窗体上放置了

SQLConnection1: TSQLConnection;
SQLDataSet1: TSQLDataSet;
DataSetProvider1: TDataSetProvider;
ClientDataSet1: TClientDataSet;
DataSource1: TDataSource;
Image1: TImage;

2个Button。一个Image1。

完整代码如下：

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, WideStrings, DB, SqlExpr, DBCtrls, SnDBImage, StdCtrls, AdvCombo,
ImagePicker, FMTBcd, Provider, DBClient, cxControls, cxContainer, cxEdit,
cxImage, cxDBEdit, ExtCtrls,jpeg, ExtDlgs, FlatCtrls, FlatCtrdb;

type
TForm1 = class(TForm)
SQLConnection1: TSQLConnection;
SQLDataSet1: TSQLDataSet;
DataSetProvider1: TDataSetProvider;
ClientDataSet1: TClientDataSet;
DataSource1: TDataSource;
Image1: TImage;
ClientDataSet1BlobField: TBlobField;
Button1: TButton;
OpenPictureDialog1: TOpenPictureDialog;
Button2: TButton;
Button3: TButton;
FlatDBEdit1: TFlatDBEdit;
ClientDataSet1StringField: TStringField;
procedure ClientDataSet1AfterScroll(DataSet: TDataSet);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin//新增图片

if Self.OpenPictureDialog1.Execute then
begin
Self.ClientDataSet1.Insert;
Self.Image1.Picture.LoadFromFile(Self.OpenPictureDialog1.FileName);

ClientDataSet1BlobField.LoadFromFile(Self.OpenPictureDialog1.FileName);
end;

end;

procedure TForm1.Button2Click(Sender: TObject);
begin//保存
Self.ClientDataSet1.ApplyUpdates(0);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin//编辑图片字段
if Self.OpenPictureDialog1.Execute then
begin
Self.ClientDataSet1.Edit;
Self.Image1.Picture.LoadFromFile(Self.OpenPictureDialog1.FileName);
ClientDataSet1BlobField.LoadFromFile(Self.OpenPictureDialog1.FileName);
end;
end;

procedure TForm1.ClientDataSet1AfterScroll(DataSet: TDataSet);
begin//每选择一个记录自动读取图片
ClientDataSet1BlobField.SaveToFile('123.jpg');
Self.Image1.Picture.LoadFromFile('123.jpg');
end;

end.