数据集和非数据感知控件使用

 1 unit frmMainUnit;  2 
 3 interface
 4 
 5 uses
 6  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  7   jpeg, // 这里是一些手工的引用
 8  Dialogs, DB, ADODB, StdCtrls, DBCtrls, Mask, Grids, DBGrids, Buttons, Menus,  9  ExtCtrls, ExtDlgs;  10 
 11 type
 12   TfrmMain = class(TForm)  13  ADOConnection1: TADOConnection;  14  ADOQuery1: TADOQuery;  15  DataSource1: TDataSource;  16  DBGrid1: TDBGrid;  17  DBEdit1: TDBEdit;  18  DBComboBox1: TDBComboBox;  19  Label1: TLabel;  20  Label2: TLabel;  21  DBEdit2: TDBEdit;  22  Label3: TLabel;  23  DBEdit3: TDBEdit;  24  Label4: TLabel;  25  DBEdit4: TDBEdit;  26  Label5: TLabel;  27  BitBtn1: TBitBtn;  28  BitBtn2: TBitBtn;  29  BitBtn3: TBitBtn;  30  Label8: TLabel;  31  Panel1: TPanel;  32  Image1: TImage;  33  PopupMenu1: TPopupMenu;  34  A1: TMenuItem;  35  N1: TMenuItem;  36  B1: TMenuItem;  37  N2: TMenuItem;  38  C1: TMenuItem;  39  p1: TOpenPictureDialog;  40  p2: TSavePictureDialog;  41     procedure FormCreate(Sender: TObject);  42     procedure ADOQuery1AfterPost(DataSet: TDataSet);  43     procedure ADOQuery1BeforeEdit(DataSet: TDataSet);  44     procedure ADOQuery1NewRecord(DataSet: TDataSet);  45     procedure BitBtn2Click(Sender: TObject);  46     procedure BitBtn1Click(Sender: TObject);  47     procedure BitBtn3Click(Sender: TObject);  48     procedure A1Click(Sender: TObject);  49     procedure ADOQuery1AfterScroll(DataSet: TDataSet);  50     procedure B1Click(Sender: TObject);  51     procedure C1Click(Sender: TObject);  52     procedure Image1DblClick(Sender: TObject);  53   private
 54     { Private declarations }
 55     function ShowImage(DataSet: TDataSet; FieldName: string; Image: TImage;  56  Panel: TPanel): Boolean;  57   public
 58     { Public declarations }
 59   end;  60 
 61 var
 62  frmMain: TfrmMain;  63 
 64 implementation
 65 
 66 {$R *.dfm}
 67 
 68 
 69 function TfrmMain.ShowImage(DataSet: TDataSet; FieldName: string; Image:  70  TImage; Panel: TPanel): Boolean;  71 var
 72  ms: TMemoryStream;  73  JI: TJpegImage;  74 begin
 75   ms := TMemoryStream.Create;  76   JI := TJpegImage.Create;  77   try
 78     try // 图片均以jpg格式保存，不支持使用dbimage，都在AfterScroll事件中读取。
 79  TBlobField(DataSet.FieldByName(FieldName)).SaveToStream(ms);  80       if ms.Size > 0 then
 81       begin
 82         ms.Position := 0;  83  JI.LoadFromStream(ms);  84  Image.Picture.Bitmap.Assign(JI);  85         if (Image.Picture.Bitmap.Width > 119) or (Image.Picture.Bitmap.Width >
 86           137) then
 87           Image.Stretch := True  88         else
 89           Image.Stretch := false;  90         Panel.Caption := '';  91       end
 92       else
 93       begin
 94         Image.Picture := nil;  95         Panel.Caption := '无照片';  96       end;  97     finally
 98       FreeAndNil(ms);  99       FreeAndNil(JI); 100     end; 101     result := True; 102   except
103     result := false; 104   end; 105 end; 106 
107 procedure TfrmMain.A1Click(Sender: TObject); 108 var
109  ms: TMemoryStream; 110  JI: TJpegImage; 111 begin
112   if not ADOQuery1.Active then
113  exit; 114   if p1.Execute then
115   begin
116     ms := TMemoryStream.Create; 117     JI := TJpegImage.Create; 118     try // 图片读取后都转换成jpg格式并压缩后保存到数据库中。
119       if lowercase(ExtractFileExt(p1.FileName)) = '.bmp' then
120       begin
121  Image1.Picture.LoadFromFile(p1.FileName); 122  JI.Assign(Image1.Picture.Bitmap); 123       end
124       else
125       begin
126  JI.LoadFromFile(p1.FileName); 127  Image1.Picture.Bitmap.Assign(JI); 128       end; 129       JI.CompressionQuality := 75; // 图片压缩比，越低越不清楚。
130  JI.Compress; 131  JI.SaveToStream(ms); 132       if not(ADOQuery1.State in dsEditModes) then
133  ADOQuery1.Edit; 134       TBlobField(ADOQuery1.FieldByName('fphoto')).LoadFromStream(ms); 135       if (Image1.Picture.Bitmap.Width > 119) or (Image1.Picture.Bitmap.Height >
136         137) then
137         Image1.Stretch := True 138       else
139         Image1.Stretch := false; 140       Panel1.Caption := ''; 141     finally
142       FreeAndNil(ms); 143       FreeAndNil(JI); 144  JI.Free; 145     end; 146   end; 147 end; 148 
149 procedure TfrmMain.ADOQuery1AfterPost(DataSet: TDataSet); 150 begin // 保存或退出编辑状态时，显示为删除
151   BitBtn2.Caption := '删除 &D'; 152 end; 153 
154 procedure TfrmMain.ADOQuery1AfterScroll(DataSet: TDataSet); 155 begin
156   ShowImage(ADOQuery1, 'fphoto', Image1, Panel1); 157 end; 158 
159 procedure TfrmMain.ADOQuery1BeforeEdit(DataSet: TDataSet); 160 begin // 进入编辑状态时，显示为取消
161   BitBtn2.Caption := '取消 &D'; 162 end; 163 
164 procedure TfrmMain.ADOQuery1NewRecord(DataSet: TDataSet); 165 begin // 这里处理新增
166   ADOQuery1.FieldByName('fsex').AsString := '男'; 167 end; 168 
169 procedure TfrmMain.B1Click(Sender: TObject); 170 begin
171   if not ADOQuery1.Active then
172  exit; 173   if ADOQuery1.State in dsEditModes then
174  exit; 175   if TBlobField(ADOQuery1.FieldByName('FPhoto')).IsNull then
176     exit; // 如果图片为空，就没必要继续了
177   if p2.Execute then
178     if ExtractFileExt(p2.FileName) = '' then
179       TBlobField(ADOQuery1.FieldByName('FPhoto')) 180         .SaveToFile(p2.FileName + '.jpg') 181     else
182       TBlobField(ADOQuery1.FieldByName('FPhoto')).SaveToFile(p2.FileName); 183 end; 184 
185 procedure TfrmMain.BitBtn1Click(Sender: TObject); 186 begin
187  ADOQuery1.Append; 188 end; 189 
190 procedure TfrmMain.BitBtn2Click(Sender: TObject); 191 begin
192   if ADOQuery1.State in dsEditModes then
193  ADOQuery1.Cancel 194   else
195     if Application.MessageBox('是否删除当前记录？', '提示信息', MB_OKCANCEL +
196     MB_ICONQUESTION + MB_DEFBUTTON2) = IDOK then
197  ADOQuery1.Delete; 198   ShowImage(ADOQuery1, 'fphoto', Image1, Panel1); 199 end; 200 
201 procedure TfrmMain.BitBtn3Click(Sender: TObject); 202 begin
203  ADOQuery1.Post; 204 end; 205 
206 procedure TfrmMain.C1Click(Sender: TObject); 207 begin
208   if not ADOQuery1.Active then
209  exit; 210   if TBlobField(ADOQuery1.FieldByName('fphoto')).IsNull then
211  exit; 212   if MessageBox(Application.Handle, '是否清除照片？', '提示信息', 213     MB_ICONQUESTION + MB_YESNO + MB_DEFBUTTON2) = IDNO then
214  exit; 215   Image1.Picture := nil; 216   if not(ADOQuery1.State in dsEditModes) then
217  ADOQuery1.Edit; 218   TBlobField(ADOQuery1.FieldByName('fphoto')).Clear; 219   ShowImage(ADOQuery1, 'fphoto', Image1, Panel1); 220 end; 221 
222 procedure TfrmMain.FormCreate(Sender: TObject); 223 begin
224   with ADOQuery1 do
225   begin
226  close; 227     sql.Text := 'select * from temployee'; 228  Open; 229   end; 230 end; 231 
232 procedure TfrmMain.Image1DblClick(Sender: TObject); 233 var
234  mPoint: TPoint; 235 begin
236  GetCursorPos(mPoint); 237  PopupMenu1.Popup(mPoint.X, mPoint.Y); 238 end; 239 
240 end.