Delphi¶àÏß³Ìѧϰ£º¶àÏß³ÌÊý¾Ý¿â²éѯ£¨ADO£©
ADO¶àÏß³ÌÊý¾Ý¿â²éѯͨ³£»á³öÏÖ3¸öÎÊÌ⣺
1¡¢CoInitialize ûÓе÷ÓÃ
£¨CoInitialize was not
called£©£»ËùÒÔ£¬ÔÚʹÓÃÈκÎdbGo¶ÔÏóÇ°£¬±ØÐëÊÖ
µ÷ÓÃCoInitializeºÍCoUninitialize¡£µ÷ÓÃCoInitializeʧ°Ü»á²úÉú"CoInitialize was not
called"ÀýÍâ¡£
2¡¢»²¼²»ÔÊÐí»æ»
£¨Canvas does not allow
drawing£©£»ËùÒÔ£¬±ØÐëͨ¹ýSynchronize¹ý³ÌÀ´Í¨ÖªÖ÷Ï̷߳ÃÎÊÖ÷´°ÌåÉϵÄÈκοؼþ¡£
3¡¢²»ÄÜʹÓÃÖ÷ADOÁ¬½Ó
£¨Main TADoConnection cannot be
used!£©£»ËùÒÔ£¬Ïß³ÌÖв»ÄÜʹÓÃÖ÷Ïß³ÌÖÐTADOConnection¶ÔÏó£¬Ã¿¸öÏ̱߳ØÐë´´½¨×Ô¼ºµÄÊý¾Ý¿âÁ¬½Ó¡£
Delphi2007°²×°ºóÔÚX:\Program Files\Common Files\CodeGear
Shared\DataĿ¼ÏÂÓÐÒ»¸ödbdemos.mdbÎļþ£¬ÓÃÀ´×÷Ϊ²âÊÔµÄÀý×Ó¡£dbdemos.mdbÖеÄcustomer±í±£´æÁË¿Í»§ÐÅ
Ï¢£¬orders±íÖб£´æÁ˶©µ¥ÐÅÏ¢¡£
²âÊÔ³ÌÐòÁ÷³Ì´óÖÂÊÇÕâÑùµÄ£ºÔÚÖ÷´°ÌåÉÏ·ÅTADOConnectionºÍTQuery¿Ø¼þ£¬Æô¶¯Ê±Õâ¸öTQuery´ÓCustomer±íÖвé³ö¿Í»§±àÂë
CustNoºÍ¹«Ë¾Ãû³ÆCompany£¬·Åµ½Èý¸öCombox¿òÖУ¬·Ö±ðÔÚÈý¸öÁбí¿òÖÐÑ¡¶¨¿Í»§¹«Ë¾Ãû³Æ£¬°´ÕÕ¹«Ë¾Ãû³ÆËù¶ÔÓ¦µÄ¿Í»§´úÂ뽨Á¢Èý¸öÏß³Ìͬʱ
ÔÚorders±íÖвéѯÏúÊÛÈÕÆÚSaleDate·Ö±ðÌîÈëListBoxÖС£
{Ö÷´°Ìå´úÂë}
unit
Main;
interface
uses
Windows,
Messages,
SysUtils,
Variants,
Classes,
Graphics,
Controls,
Forms,
Dialogs,
DB,
ADODB,
StdCtrls;
type
TForm2 =
class
(
TForm)
ComboBox1:
TComboBox;
ComboBox2:
TComboBox;
ComboBox3:
TComboBox;
ListBox1:
TListBox;
ListBox2:
TListBox;
ListBox3:
TListBox;
Button1:
TButton;
ADOConnection1:
TADOConnection;
ADOQuery1:
TADOQuery;
Label1:
TLabel;
Label2:
TLabel;
Label3:
TLabel;
procedure
FormCreate(
Sender:
TObject
)
;
procedure
Button1Click(
Sender:
TObject
)
;
private
{ Private declarations }
public
{ Public declarations }
end
;
var
Form2:
TForm2;
implementation
uses
ADOThread;
{$R *.dfm}
procedure
TForm2.
Button1Click
(
Sender:
TObject
)
Ïà¹ØÎĵµ£º
1.Round£¨ËÄÉáÁùÈëÎåÁôË«£©
¹¦ÄÜ˵Ã÷£º¶ÔÒ»¸öʵÊý½øÐÐËÄÉáÎåÈë¡£(°´ÕÕÒøÐмÒËã·¨)
Àý£º
var
i, j: Integer;
begin
i := Round(1.5); // iµÈÓÚ2
j := Round(2.5); // jµÈÓÚ2
end;
ÔÚDelphiÖÐʹÓÃRoundº¯ÊýµÃµ½µÄ´ð°¸ÓÐʱÓëÎÒÃÇËùÔ¤ÆڵĻ᲻̫һÑù£º²ÉÓõÄÊÇËÄÉáÁùÈëÎåÁôË«¡£¼´µ±Éá»òÈëλ´óÓÚ»òСÓÚÎåÊ ......
Day ¿ªÍ·µÄº¯Êý
¡ñ
Unit
DateUtils
function DateOf(const Avalue: TDateTime): TDateTime;
ÃèÊö
ʹÓà DateOf º¯ÊýÓÃÀ´°ÑÒ»¸ö TDateTime ÀàÐ͵ıäÁ¿×ª±ä³ÉÒ»¸ö
Ö»´øÓÐÈÕÆÚµÄ TDateTime ÀàÐͱäÁ¿¡£
ÀýÈ磺
showmessage(DateTimetostr(dateof(now())));
ÄãµÃµ½µÄÊÇ 2003/03/19
¶ø showmessage(Dat ......
====================================================
Delphi²Ù×÷ÎļþµÄÒ»°ã²½Ö裺
1£©¹ØÁªÎļþ£º
AssignFile(var F; FileName :string)£»
2£©³õʼ»¯Îļþ£º
Append(var F :Text);
//ֻд£¬ÓÚÎļþ×îºó×·¼ÓÊý¾Ý
Reset(var F [; RecSize :Word]);   ......
´ó¼ÒÔÚÈí¼þ¿ª·¢Ê±¾³£»áÓöµ½ÕâÑùµÄÇé¿ö£¬ÔÚ²»Í¬µÄ¿ª·¢»·¾³ÖÐΪʵÏÖһЩ¹¦ÄÜÏàͬµÄ¹ý³Ì£¬ÓÉÓÚ¿ª·¢ËùʹÓõÄÉè¼ÆÓïÑÔ²»Í¬£¬Òò¶ø²»µÃ²»±àдÐí¶àÀàËƵĴúÂ룬ÉõÖÁÓÐʱҪÔÚͬһ¸ö¿ª·¢»·¾³²»Í¬ÏîÄ¿ÖÐÖØд´úÂ룬Õâ¾ÍÔì³ÉÁ˺ܴóµÄ×ÊÔ´ÀË·Ñ¡£¶¯Ì¬Á´½Ó¿âÄܽϺõĽâ¾öÕâ¸öÎÊÌ⣬Öظ´ÀûÓôúÂ뽫´ó´óÌá¸ßÁË¿ª·¢Ð§ÂÊ¡£Ò»°ã£¬Óû§ÔÚÓ¦ÓóÌÐò ......
boolÊÇLongBoolÀàÐÍ¡£
DelphiÖж¨ÒåÁËËÄÖÖ²¼¶ûÀàÐÍ£ºBoolean£¬ByteBool£¬WordBoolºÍLongBool¡£ºóÃæÈýÖÖ²¼¶ûÀàÐÍÊÇΪÁËÓëÆäËûÓïÑÔ¼æÈݶøÒýÈëµÄ£¬Ò»°ãÇé¿öϽ¨ÒéʹÓÃBooleanÀàÐÍ¡£
ÕâËÄÖÖÀàÐ͵IJ¼¶ûÖµÕ¼ÓÃÄÚ´æµÄÊýÁ¿ÈçÏ£º
Boolean 1 Byte
ByteBool 1 Byte
WordBool 2 Bytes£¨1 Word£©
LongBool 4 Bytes£¨2 Words£©
¶Ô ......