DBLookupComboBox
Otázka od: David Liska
25. 11. 2003 16:00
Ahoj,
potreboval bych komponentu jako je DBLookupComboBox, ale s tim aby to
uzivateli predepisovalo znamy text (napise par pismen a ma to nabizet zbytek
z nejakeho lookup datasetu).
Nemate nekdo neco takoveho?
Predem diky, David
----------
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Odpovedá: LUKES Vaclav
25. 11. 2003 16:25
Podivej se na JEDI...
V.
-----Original Message-----
From: David Liska [mailto:konference@thsoft.cz]
Sent: Tuesday, November 25, 2003 3:47 PM
To: delphi-l@clexpert.cz
Subject: DBLookupComboBox
Ahoj,
potreboval bych komponentu jako je DBLookupComboBox, ale s tim aby to
uzivateli predepisovalo znamy text (napise par pismen a ma to nabizet zbytek
z nejakeho lookup datasetu).
Nemate nekdo neco takoveho?
Predem diky, David
----------
* www.inMail.sk - Vasa emailova adresa na cely zivot ZDARMA
* Mail neobsahuje virusy. Zkontrolovane antivirusom NOD32 (www.eset.sk)
* www.SlovakNET.sk - profesionalny webhosting, domena .SK ZADARMO
* Zoner Media Explorer 5 - stiahnite si pomocnika pre digitalnu fotografiu
(zme.zoner.sk)
Odpovedá: Jiri Virt
25. 11. 2003 16:14
unit JVDBLookupComboSearch;
interface
uses
SysUtils, WinTypes,WinProcs, Messages, Classes, Graphics, Controls,
Forms, Dialogs, StdCtrls, DBLookup, DB, DBTables;
type
JVDBLookupCombo = class(TDBLookupCombo)
private
CanChange: Boolean;
FieldLength: Integer;
LimitedToList: boolean;
HadWildCard: Boolean;
Ordered: Boolean;
Entered: Boolean;
SearchField: TField;
SearchType 
SuperSlow,Slow,Fast);
protected
procedure DoEnter; override;
procedure DoExit; override;
procedure Change; override;
procedure KeyDown(var Key: Word; Shift: TShiftState); override;
public
constructor Create(AOwner: TComponent); override;
procedure FindRow;
published
property LimitTolist: Boolean read LimitedToList write LimitedToList
default False;
property IsOrdered: boolean read Ordered write Ordered default False;
end;
procedure Register;
procedure FindCarefully(Table: TDataSet;SearchField: TField; const
SubString: String);
procedure FindContaining(Table: TDataSet ;SearchField: TField; const
SubString: String; Down: Boolean);
{procedure FindQuick(Table: TDataSet;Field: String; const SubString:
String);
procedure SearchQuick(const DataSet: TDataSet;const SearchField:
TField; const SubString: String 1024: integer);}
implementation
procedure FindCarefully(Table: TDataSet;SearchField: TField; const
SubString: String);
begin
try
with Table do
begin
DisableControls;
if CompareText(SubString,(SearchField.AsString))>0 then
while (CompareText(SubString,(SearchField.AsString))>0) AND (not EOF) do
Next
else
begin
while (CompareText(SubString,(SearchField.AsString))<0) AND (not BOF) do
Prior;
if (CompareText(SubString,(SearchField.AsString))>0) then Next;
end;
end;
finally
Table.EnableControls;
end;
end;
procedure FindContaining(Table: TDataSet;SearchField: TField; const
SubString: String; Down: Boolean);
var
CapSubString: String;
begin
try
CapSubString:=UpperCase(SubString);
with Table do
begin
DisableControls;
if Down then
while ((Pos(CapSubString,UpperCase(SearchField.AsString))=0)AND (not
EOF)) do Next
else
while ((Pos(CapSubString,UpperCase(SearchField.AsString))=0)AND(not
BOF))do Prior;
if EOF then First;
end;
finally
Table.EnableControls;
end;
end;
procedure JVDBLookupCombo.Change;
var
{ source: TDataSource;}
CurrentValue: String; FirstChar: string[1];
begin
inherited Change;
if CanChange then
begin
try
CanChange:=False;
CurrentValue:=Text;
FirstChar:= CurrentValue;
if (FirstChar='*') or (FirstChar='%') then
begin
if HadWildCard=False or (FieldLength>Length(CurrentValue)) then
LookUpSource.DataSet.First;
HadWildCard:=True;
end
else
begin
case SearchType of
Superslow:
FindCarefully(LookUpSource.DataSet,SearchField,CurrentValue);
Slow :
FindCarefully(LookUpSource.DataSet,SearchField,CurrentValue);
Fast LookUpSource.DataSet as
TTable).FindNearest([CurrentValue]);
end;
HadWildCard:=False;
end;
finally
CanChange:=True;
FieldLength:=Length(CurrentValue);
end;
end;
end;
constructor JVDBLookupCombo.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
CanChange:=False;
LimitedToList:=False;
HadWildCard:=False;
FieldLength:=0;
Ordered:=False;
Entered:=False;
end;
procedure JVDBLookupCombo.DoEnter;
var
Field, IndexField: String;
begin
try
DropDown;
HadWildCard:=False;
CanChange:=True;
Entered:=True;
if Pos(';',Lookupdisplay)>0 then
Field:=Copy(Lookupdisplay,1,Pos(';',Lookupdisplay)-1)
else Field:= Lookupdisplay;
SearchField:=LookUpSource.DataSet.FindField(Field);
IndexField:=Copy((LookUpSource.DataSet as
TTable).IndexFieldNames,1,length(Field));
CanChange:=Assigned(SearchField);
if (LookUpSource.DataSet is TTable) then
if CompareText(Field,IndexField)=0 then
SearchType:=Fast
else
if Ordered then SearchType:=Slow else SearchType:=SuperSlow
else
if Ordered then SearchType:=Slow else SearchType:=SuperSlow;
DropDown;
inherited DoEnter;
Change;
except
SearchType:=SuperSlow;
end;
end;
procedure JVDBLookupCombo.DoExit;
begin
try
if LimitedToList then
begin
{CanChange:=False;}
with DataSource.DataSet do
if (State=dsEdit) or (State=dsInsert) then
begin
Text:=SearchField.AsString;
end;
end;
finally
CloseUp;
inherited DoExit;
end;
end;
procedure JVDBLookupCombo.KeyDown(var Key: Word; Shift: TShiftState);
begin
case Key of
VK_RETURN:begin
if not (LookUpSource.DataSet.Locate(LookupField,Value,[])) then
begin
Key := 0;
SetFocus;
end else CloseUp;
end;{VK_RETURN}
end; {case}
inherited KeyDown(Key,Shift);
end;
procedure JVDBLookupCombo.FindRow;
begin
if Entered then DoEnter else Change;
end;
procedure Register;
begin
RegisterComponents('JV', [JVDBLookupCombo]);
end;
end.
Spachal
Jiri Virt
----------
* www.inMail.sk - Vasa emailova adresa na cely zivot ZDARMA
* Mail neobsahuje virusy. Zkontrolovane antivirusom NOD32 (www.eset.sk)
* www.SlovakNET.sk - profesionalny webhosting, domena .SK ZADARMO
* Zoner Media Explorer 5 - stiahnite si pomocnika pre digitalnu fotografiu
(zme.zoner.sk)