Delphi复习纲要.doc

_Delphi复习纲要implementationvar s,s1,s2:string;xop:array0.10 of string;procedure TForm1.BitBtn1Click(Sender: TObject);beginxop0:=;xop1:=;xop2:=;xop3:=;xop4:=;xop5:=;s1:=dbgrid1.Columnscombobox1.ItemIndex.FieldName+xopcombobox2.ItemIndex+edit1.Text+;if combobox3.itemindex=0 thenbegins2:=dbgrid1.Columnscombobox4.ItemIndex.FieldName+xopcombobox5.ItemIndex+edit2.Text+;adoquery1.close;adoquery1.sql.text:=select * from s where +s1+ and +s2;adoquery1.open;endelse if combobox3.itemindex=1 thenbegins2:=dbgrid1.Columnscombobox4.ItemIndex.FieldName+xopcombobox5.ItemIndex+edit2.Text+;adoquery1.close;adoquery1.sql.text:=select * from s where +s1+ or +s2;adoquery1.open;endelsebeginadoquery1.close;adoquery1.sql.text:=select * from s where +s1;adoquery1.open;end;end;procedure TForm1.ComboBox3Click(Sender: TObject);begincombobox4.Visible:=true;combobox5.Visible:=true;edit2.Visible:=true;end;end.implementationprocedure TForm2.BitBtn1Click(Sender: TObject);varff:textfile;s1,s2,s3:string;beginassignfile(ff,d:a1.txt); /新建并打开文件rewrite(ff); /Rewrite 过程能创建一个新文件并打开它；使用Reset 打开的/文本文件是只读的，使用Rewrite 和Append 打开的文本文件只能写入adoquery1.Close;adoquery1.SQL.Text:=select * from categories ;adoquery1.Open;with adoquery1 dobegin disablecontrols; first; while not eof do begin s1:=fieldbyname(categoryid).AsString; s2:=fieldbyname(categoryname).AsString; s3:=fieldbyname(description).AsString; writeln(ff,s1+ +s2+ +s3); next; end; closefile(ff); enablecontrols;end;memo1.Lines.Clear;memo1.Lines.LoadFromFile(d:a1.txt);categorypanel1.Collapsed:=false;categorypanel2.Collapsed:=true;end;procedure TForm2.BitBtn2Click(Sender: TObject);vars,s1,s2:string;nd:ttreenode;beginTreeView1.Items.Clear;adoquery1.disablecontrols;adoquery1.Close;adoquery1.SQL.Text:=select * from categories ;adoquery1.Open;while not adoquery1.Eof dobegin s:=adoquery1.FieldByName(categoryname).AsString; s1:=adoquery1.FieldByName(categoryid).AsString; ADOQuery2.Close; adoquery2.SQL.Text:=select * from products where categoryid=:s1 ; adoquery2.Parameters.ParamByName(s1).value:=s1; adoquery2.open; nd:=treeview1.Items.Add(nil,s); adoquery2.disablecontrols; adoquery2.first; while not adoquery2.Eof do begin s2:=adoquery2.FieldByName(productid).AsString+ +adoquery2.FieldByName(productname).AsString; treeview1.Items.AddChild(nd,s2); adoquery2.Next; end; adoquery2.enablecontrols; adoquery1.Next;end;adoquery1.enablecontrols;categorypanel1.Collapsed:=true;categorypanel2.Collapsed:=false;end;end.方法一：见课本P123页；利用Delphi语句和数组产生树节点procedure TForm4.FormShow(Sender: TObject);var s:string; k:integer; node:array1.3 of ttreenode;beginadoquery1.Close;adoquery1.SQL.Text:=select * from x_city order by cityid ;adoquery1.Open;while not adoquery1.Eof dobegins:=adoquery1.FieldByName(cityid).AsString+ +adoquery1.FieldByName(city).AsString;k:=adoquery1.Field