querybook.pas

这是一个DELPHI7应用案例开发篇有配套程序种子光盘

unit QueryBook;
{PUBDIST}

interface

uses
  IWAppForm, IWApplication, IWTypes, Classes, Controls, IWControl, IWGrids,
  IWDBGrids, IWCompEdit, IWCompLabel, IWCompButton, IWDBStdCtrls,
  IWHTMLControls, DB, IWExtCtrls, DBXpress, FMTBcd, SqlExpr, IWCompMemo,
  IWCompListbox, SysUtils, Graphics, Jpeg, Variants;

type
  TfrmQueryBook = class(TIWAppForm)
    IWDBGrid1: TIWDBGrid;
    IWLabel1: TIWLabel;
    edQBook: TIWEdit;
    IWLabel2: TIWLabel;
    edQAuthor: TIWEdit;
    IWLabel3: TIWLabel;
    edQPrice: TIWEdit;
    btnQuery: TIWButton;
    IWHRule1: TIWHRule;
    IWDBNavigator1: TIWDBNavigator;
    IWLabel4: TIWLabel;
    IWLabel5: TIWLabel;
    IWLabel6: TIWLabel;
    IWLabel7: TIWLabel;
    IWLabel8: TIWLabel;
    IWImage1: TIWImage;
    dsBook: TDataSource;
    IWDBLabel1: TIWDBLabel;
    IWDBLabel2: TIWDBLabel;
    IWDBLabel3: TIWDBLabel;
    IWDBLabel4: TIWDBLabel;
    lbAuthor: TIWLabel;
    IWDBMemo1: TIWDBMemo;
    IWDBMemo2: TIWDBMemo;
    cbCompPrice: TIWComboBox;
    cbOrderField: TIWComboBox;
    IWLabel9: TIWLabel;
    cbOrderStyle: TIWComboBox;
    IWLabel10: TIWLabel;
    lbRecCount: TIWLabel;
    btnAddToCarter: TIWButton;
    btnCheckCarter: TIWButton;
    procedure IWAppFormCreate(Sender: TObject);
    procedure dsBookDataChange(Sender: TObject; Field: TField);
    procedure btnQueryClick(Sender: TObject);
    procedure IWDBGrid1Columns0Click(ASender: TObject;
      const AValue: String);
    procedure IWDBGrid1RenderCell(ACell: TIWGridCell; const ARow,
      AColumn: Integer);
    procedure btnAddToCarterClick(Sender: TObject);
    procedure btnCheckCarterClick(Sender: TObject);
  public
  end;

implementation
{$R *.dfm}

uses
  ServerController, DatamoduleUnit, DIMime, Carter;

procedure TfrmQueryBook.IWAppFormCreate(Sender: TObject);
begin
    dsBook.DataSet := DataModule1.cdsBook;
end;

procedure TfrmQueryBook.dsBookDataChange(Sender: TObject; Field: TField);
var
    jImage:TJpegImage;
    ss: TStringStream;
    bSize : Integer;
begin
    with DataModule1.cdsBook do
    begin
        if RecNo>0 then
        begin
            lbAuthor.Caption := FieldByName('Author1').AsString+', '+
                FieldByName('Author2').AsString+', '+
                FieldByName('Author3').AsString;
        end;
    end;

    bSize :=TBlobField(DataModule1.cdsBook.FieldByName('BookCover')).BlobSize;
    if bSize>0 then
    begin
        jImage := TJpegImage.Create;
        with DataModule1 do
        begin
            ss := TStringStream.Create(MIMEDecodeString(cdsBook.FieldByName('BookCover').AsString));
            ss.Seek(0, soFromBeginning);
            jImage.LoadFromStream(ss);
            IWImage1.Picture.Assign(jImage);
            ss.Free;
        end;
        jImage.Free;
    end;
end;

procedure TfrmQueryBook.btnQueryClick(Sender: TObject);
const
    INFI = 999999;
var
    SQLs : String;
    bookname, authorname1, authorname2, authorname3, authorname4, authorname5:String;
    lowbound, highbound : Real;
begin
    SQLs := 'SELECT * FROM tb_book WHERE'+
    '(BookName like %s) and '+
    '((Author1 like %s) or '+
    '(Author2 like %s) or '+
    '(Author3 like %s) or '+
    '(Author4 like %s) or '+
    '(Author5 like %s)) and '+
    '(SellPrice > %4.2f) and'+
    '(SellPrice < %4.2f) '+
    'ORDER BY ';

    DataModule1.cdsBook.Close;
    with DataModule1.qrBook do
    begin
        Close;
        SQL.Clear;

        if (cbOrderField.ItemIndex = 1) then
        begin
            SQLs := SQLs+'SellPrice';
        end
        else
        begin
            SQLs := SQLs+'PubDate';
        end;


        if (cbOrderStyle.ItemIndex = 0) then
        begin
            SQLs := SQLs+' ASC';
        end
        else
            SQLs := SQLs+' DESC';

        if edQBook.Text <> '' then
        begin
            bookname := Format('''%%%s%%''',
                [edQBook.Text]);
        end
        else
            bookname := '''%''';

        if edQAuthor.Text <> '' then
        begin
            authorname1 := Format('''%s''',
                [edQAuthor.Text]);
            authorname2 := Format('''%s''',
                [edQAuthor.Text]);
            authorname3 := Format('''%s''',
                [edQAuthor.Text]);
            authorname4 := Format('''%s''',
                [edQAuthor.Text]);
            authorname5 := Format('''%s''',
                [edQAuthor.Text]);
        end
        else
        begin
            authorname1 := '''%''';
            authorname2 := '''%''';
            authorname3 := '''%''';
            authorname4 := '''%''';
            authorname5 := '''%''';
        end;

        if (cbCompPrice.ItemIndex = 0) and (edQPrice.Text <> '') then
        begin
            lowbound := 0;
            highbound := StrToInt(edQPrice.Text);
        end
        else if (cbCompPrice.ItemIndex = 1) and (edQPrice.Text <> '') then
        begin
            lowbound := StrToInt(edQPrice.Text);
            highbound := INFI;
        end
        else
        begin
            lowbound := 0;
            highbound := INFI;
        end;

        SQL.Text := Format(SQLs,[bookname, authorname1, authorname2, authorname3, authorname4, authorname5,
            lowbound, highbound]);

        Open;
    end;
    DataModule1.cdsBook.Open;

    lbRecCount.Text := IntToStr(DataModule1.cdsBook.RecordCount);
end;

procedure TfrmQueryBook.IWDBGrid1Columns0Click(ASender: TObject;
  const AValue: String);
begin
    DataModule1.cdsBook.Locate('BookSerial',AValue, []);
end;

procedure TfrmQueryBook.IWDBGrid1RenderCell(ACell: TIWGridCell; const ARow,
  AColumn: Integer);
begin
    if IWDBGrid1.RowIsCurrent then
        ACell.BGColor := clYellow;
end;

procedure TfrmQueryBook.btnAddToCarterClick(Sender: TObject);
begin
    if UserSession.UserName = '' then
    begin
        WebApplication.ShowMessage('请先登录！');
        Exit;
    end;

    with DataModule1.cdsCarter do
    begin
        if VarType(Lookup('BookSerial',
            DataModule1.cdsBook.FieldByName('BookSerial').AsString,'BookSerial'))
            in [VarNull] then
        begin
            Insert;
            FieldByName('BookSerial').AsString :=
                DataModule1.cdsBook.FieldByName('BookSerial').AsString;
            FieldByName('BookCount').AsInteger := 1;
            Post;
        end;

        WebApplication.ShowMessage('书籍已放入购物箱，请继续选购');
    end;
end;

procedure TfrmQueryBook.btnCheckCarterClick(Sender: TObject);
begin
    if UserSession.UserName = '' then
    begin
        WebApplication.ShowMessage('请先登录！');
        Exit;
    end;

    TIWAppForm(WebApplication.ActiveForm).Release;
    TfrmCarter.Create(WebApplication).Show;
end;

end.