前言
增量搜索(又叫渐进搜索)是我比较喜欢的一种搜索方式，这种一边输入一边搜索的模式常常能更快的找到关键字，特别是在关键字记 得不全的时候。大部分代码编辑器都提供了增量搜索的功能，比如Delphi，VS。在Delphi，我用得最多的快捷键几乎就是Ctrl+E了。
这几天突然心血来潮，研究了一下增量搜索的原理，成果就是这篇文章，这大概不是最好的实现，不过从搜 索速度和结果来看，基本已经满足要求了，这一点从大文件(比如Windows.pas)的测试可以证实。
基本原理就是每输入一个字符就从前一个匹配的位置起搜索关键字，得到的匹配块压进一个栈中。在回退的 时候从栈中弹出一个匹配块，然后定位到这个匹配块所指的位置。
更加详细的实现请看下面的代码。
类结构设计
在实现之前，我认为一定有更快的方法，因此必须设计一个更具扩展性的类结构，如下图所示：
IIncreSearch定义了增量搜索的规范，任何增量搜索的类都可以实现该接口。TIncreSearch是一个默认的实现， 即上面所说的用栈结构来保存匹配块的方法。注意这里的搜索类并没有与任何控件界面关联，它是一个纯粹的类。
TIncreSearchHandler用于处理支持增量搜索的控件的一些消息，比如字符消息，搜索结束消息；同时它使用IncreSearch来实现控件的增量搜 索。
TEdtIncreSearchHandler实现了编辑类控件的增量搜索，关联的控件必须是TCustomEdit类型的。
代码
下面是代码，代码是设计的最佳说明：
代码
{**********************************************************}
{ 摘要： 编辑控件增量搜索实现 }
{ }
{ 作者： LinZhenqun }
{ 日期： 2007-10-11 }
{ 邮件： linzhenqun@gmail.net }
{**********************************************************}
unit IncreSearch;
(*******************************************************************************
说明：
1、本单元实现了一个编辑控件的增量搜索。
2、IIncreSearch指定增量搜索的规范，任何增量搜索类都应该实现该接口；
3、TIncreSearch是IIncreSearch的一个默认实现，主要是用栈来保存搜索到的匹配块。
4、TInsreSearchHandler为搜索处理器的抽象类，它使用IIncreSearch来实现增量搜索，
同时处理增量搜索的操作逻辑。
5、TEditInsreSearchHandler为编辑控件的搜索处理器，与之关联的控件必须是TCustomEdit
类型的控件。
用法：
1、实例化一个处理器，比如TEditInsreSearchHandler，并在构造函数中传进将被搜索
的控件。
2、调用StarteSearch开始增量搜索。
3、调用Searching确定增量搜索是否已经结束。
扩展：
1、增量搜索类：TIncreSearch只是一个默认的搜索实现类，这不是一个最快速的类，
如果你知道如何更快速的实现增量搜索，请实现IIncreSearch接口，并在处理器
的构造函数中传进这个类，比如：
TSomeInsreSearchHandler.Create(TSomeControl, YourIncreSearch);
处理器面对的是搜索接口，因此要特别注意其生命周期的管理。
2、搜索处理器：TEditInsreSearchHandler只能处理TCustomEdit的编辑控件，对于一
些不是从TCustomEdit继承的控件，则必须写另外的处理器。
实现很简单，继承TInsreSearchHandler，并且必须覆盖GetSearchStr，GetSearchStart，
SetMatchBlock三个抽象方法，提供搜索必需的信息。
如想提供更多的扩展，可以覆盖TInsreSearchHandler其他的虚方法。
******************************************************************************)
interface
uses
Classes, Messages, Controls, Contnrs;
type
{ 匹配的块 }
PMatchBlock = ^TMatchBlock;
TMatchBlock = record
Start: Integer;
Len: Integer;
end;
{ 增量搜索接口 }
IIncreSearch = interface
['{A8037752-ED93-49F6-915C-6D8E82ADD631}']
(* 开始搜索 *)
procedure StartSearch(const SearchStr: string; Start: Integer = 0; MaxKey: Word = 80);
(* 结束搜索 *)
procedure EndSearch;
(* 增加一个字符 *)
function IncreaseChar(C: Char): PMatchBlock;
(* 减少一个字符 *)
function DecreaseChar: PMatchBlock;
(* 是否正在搜索 *)
function GetSearching: Boolean;
property Searching: Boolean read GetSearching;
end;
{ 增量搜索的默认实现：利用栈来保存匹配块 }
TIncreSearch = class(TInterfacedObject, IIncreSearch)
private
FSearching: Boolean;
FKeyIndex: Integer;
FStart: Integer;
FSearchKey: string;
FSearchStr: string;
FMatchBlockList: TStack;
protected
procedure ClearMatchBlockList;
public
procedure StartSearch(const SearchStr: string; Start: Integer = 0; MaxKey: Word = 80);
procedure EndSearch;
function IncreaseChar(C: Char): PMatchBlock;
function DecreaseChar: PMatchBlock;
function GetSearching: Boolean;
property Searching: Boolean read GetSearching;
constructor Create;
destructor Destroy; override;
end;
{ 增量搜索处理器，抽象类 }
TIncreSearchHandler = class
private
FIncreSearch: IIncreSearch;
protected
FCtrl: TControl;
FOldCtrlWndProc: TWndMethod;
procedure HookWndProc;
procedure UnHookWndProc;
(* 控件处理过程，处理增量搜索的字符 *)
procedure CtrlWndProc(var Message: TMessage); virtual;
(* 导致增量搜索结束的消息 *)
function IsEndSearchMsg(Message: TMessage): Boolean; virtual;
(* 取得等搜索的字符串，必须由子类给出 *)
function GetSearchStr: string; virtual; abstract;
(* 取得搜索的起始位置，必须由子类给出 *)
function GetSearchStart: Integer; virtual; abstract;
(* 返回搜索关键字的最大长度 *)
function GetMaxKey: Integer; virtual;
(* 设置搜到的匹配块，必须由子类实现 *)
procedure SetMatchBlock(MatchBlock: PMatchBlock); virtual; abstract;
(* 开始搜索，子类作额外处理 *)
procedure DoEndSearch; virtual;
(* 结束搜索，子类作额外处理 *)
procedure DoStartSearch; virtual;
public
procedure StarteSearch;
procedure EndSearch;
function Searching: Boolean;
property Ctrl: TControl read FCtrl;
constructor Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil); virtual;
destructor Destroy; override;
end;
{ 编辑控件增量搜索处理器，编辑控件必须从TCustomEdit继承 }
TEdtIncreSearchHandler = class(TIncreSearchHandler)
protected
function GetSearchStr: string; override;
procedure SetMatchBlock(MatchBlock: PMatchBlock); override;
function GetSearchStart: Integer; override;
public
constructor Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil); override;
end;
implementation
uses
SysUtils, StdCtrls, Windows;
{ TIncreSearch }
procedure TIncreSearch.ClearMatchBlockList;
var
P: Pointer;
begin
if FMatchBlockList.Count > 0 then
begin
P := FMatchBlockList.Pop;
Dispose(P);
end;
while FMatchBlockList.Count > 0 do
begin
P := FMatchBlockList.Pop;
Dispose(P);
end;
end;
constructor TIncreSearch.Create;
begin
FMatchBlockList := TStack.Create;
end;
function TIncreSearch.DecreaseChar: PMatchBlock;
begin
Result := nil;
if FKeyIndex = 0 then Exit;
FSearchKey[FKeyIndex] := #0;
Dec(FKeyIndex);
if FMatchBlockList.Count > 1 then
Dispose(FMatchBlockList.Pop);
if FMatchBlockList.Count > 0 then
Result := PMatchBlock(FMatchBlockList.Peek);
end;
destructor TIncreSearch.Destroy;
begin
ClearMatchBlockList;
FMatchBlockList.Free;
inherited;
end;
procedure TIncreSearch.EndSearch;
begin
FSearching := False;
end;
function TIncreSearch.GetSearching: Boolean;
begin
Result := FSearching;
end;
function TIncreSearch.IncreaseChar(C: Char): PMatchBlock;
var
nStart: Integer;
pwSearStr, pwMatch: PChar;
begin
Result := nil;
Inc(FKeyIndex);
if FKeyIndex > Length(FSearchKey) then Exit;
if (C >= 'A') and (C <= 'Z') then
C := Chr(Ord(C) + $20);
FSearchKey[FKeyIndex] := C;
if FMatchBlockList.Count = 1 then
nStart := FStart
else
nStart := PMatchBlock(FMatchBlockList.Peek)^.Start;
pwSearStr := PChar(FSearchStr);
Inc(pwSearStr, nStart);
pwMatch := StrPos(pwSearStr, PChar(FSearchKey));
if pwMatch <> nil then
begin
New(Result);
Result^.Len := FKeyIndex;
Result^.Start := nStart + (pwMatch - pwSearStr);
FMatchBlockList.Push(Result);
end
else begin
FSearchKey[FKeyIndex] := #0;
Dec(FKeyIndex);
end;
end;
procedure TIncreSearch.StartSearch(const SearchStr: string;
Start: Integer; MaxKey: Word);
var
SearBlock: PMatchBlock;
pStr: PChar;
begin
FSearching := True;
//初始化关键字
SetLength(FSearchKey, MaxKey);
FillChar(FSearchKey[1], MaxKey, 0);
FKeyIndex := 0;
FStart := Start;
//字符串流全部变成小写
FSearchStr := SearchStr;
pStr := PChar(FSearchStr);
StrLower(pStr);
//压入一个起始位置的匹配块
ClearMatchBlockList;
New(SearBlock);
SearBlock^.Start := FStart;
SearBlock^.Len := 0;
FMatchBlockList.Push(SearBlock);
end;
{ TIncreSearchHandler }
constructor TIncreSearchHandler.Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil);
begin
FCtrl := ACtrl;
HookWndProc;
if IncreSearch = nil then
FIncreSearch := TIncreSearch.Create
else
FIncreSearch := IncreSearch;
end;
procedure TIncreSearchHandler.CtrlWndProc(var Message: TMessage);
var
MatchBlock: PMatchBlock;
C: Char;
Key: Word;
begin
if FIncreSearch.Searching then
begin
if IsEndSearchMsg(Message) then
begin
FIncreSearch.EndSearch;
DoEndSearch;
end
else begin
//处理增量搜索的字符
case Message.Msg of
WM_CHAR:
begin
C := Char(TWMChar(Message).CharCode);
if C <> #8 then
begin
MatchBlock := FIncreSearch.IncreaseChar(C);
if MatchBlock <> nil then
SetMatchBlock(MatchBlock);
end;
TWMChar(Message).CharCode := 0;
end;
WM_KEYDOWN:
begin
Key := TWMKey(Message).CharCode;
if Key = 8 then
begin
MatchBlock := FIncreSearch.DecreaseChar;
TWMKey(Message).CharCode := 0;
if MatchBlock <> nil then
SetMatchBlock(MatchBlock);
end;
end;
end;
end;
end;
FOldCtrlWndProc(Message);
end;
destructor TIncreSearchHandler.Destroy;
begin
UnHookWndProc;
FIncreSearch := nil;
inherited;
end;
procedure TIncreSearchHandler.DoEndSearch;
begin
end;
procedure TIncreSearchHandler.DoStartSearch;
begin
end;
procedure TIncreSearchHandler.EndSearch;
begin
FIncreSearch.EndSearch;
end;
function TIncreSearchHandler.GetMaxKey: Integer;
begin
Result := 80;
end;
procedure TIncreSearchHandler.HookWndProc;
begin
FOldCtrlWndProc := FCtrl.WindowProc;
FCtrl.WindowProc := CtrlWndProc;
end;
function TIncreSearchHandler.IsEndSearchMsg(Message: TMessage): Boolean;
function KeyInKeys(Key: Word): Boolean;
begin
case Key of
VK_ESCAPE, VK_RIGHT, VK_LEFT, VK_UP, VK_DOWN, VK_TAB,
VK_RETURN, VK_INSERT:
Result := True
else
Result := False;
end;
end;
begin
Result := ((Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) and
(Message.Msg <> WM_MOUSEMOVE)) or
((Message.Msg = WM_KEYDOWN) and KeyInKeys(TWMKey(Message).CharCode));
end;
function TIncreSearchHandler.Searching: Boolean;
begin
Result := FIncreSearch.Searching;
end;
procedure TIncreSearchHandler.StarteSearch;
begin
FIncreSearch.StartSearch(GetSearchStr, GetSearchStart, GetMaxKey);
end;
procedure TIncreSearchHandler.UnHookWndProc;
begin
FCtrl.WindowProc := FOldCtrlWndProc;
end;
{ TEdtIncreSearchHandler }
constructor TEdtIncreSearchHandler.Create(ACtrl: TControl;
IncreSearch: IIncreSearch);
begin
inherited;
if not (ACtrl is TCustomEdit) then
raise Exception.Create('the control must be inherited from TCustomEdit');
end;
function TEdtIncreSearchHandler.GetSearchStart: Integer;
begin
if (Ctrl is TCustomEdit) then
Result := TCustomEdit(Ctrl).SelStart
else
Result := 0;
end;
function TEdtIncreSearchHandler.GetSearchStr: string;
begin
if FCtrl is TCustomEdit then
Result := TCustomEdit(Ctrl).Text
else
Result := '';
end;
procedure TEdtIncreSearchHandler.SetMatchBlock(MatchBlock: PMatchBlock);
begin
if (FCtrl is TCustomEdit) and (MatchBlock <> nil) then
begin
TCustomEdit(Ctrl).SelStart := MatchBlock^.Start;
TCustomEdit(Ctrl).SelLength := MatchBlock^.Len;
end;
end;
end.
{ 摘要： 编辑控件增量搜索实现 }
{ }
{ 作者： LinZhenqun }
{ 日期： 2007-10-11 }
{ 邮件： linzhenqun@gmail.net }
{**********************************************************}
unit IncreSearch;
(*******************************************************************************
说明：
1、本单元实现了一个编辑控件的增量搜索。
2、IIncreSearch指定增量搜索的规范，任何增量搜索类都应该实现该接口；
3、TIncreSearch是IIncreSearch的一个默认实现，主要是用栈来保存搜索到的匹配块。
4、TInsreSearchHandler为搜索处理器的抽象类，它使用IIncreSearch来实现增量搜索，
同时处理增量搜索的操作逻辑。
5、TEditInsreSearchHandler为编辑控件的搜索处理器，与之关联的控件必须是TCustomEdit
类型的控件。
用法：
1、实例化一个处理器，比如TEditInsreSearchHandler，并在构造函数中传进将被搜索
的控件。
2、调用StarteSearch开始增量搜索。
3、调用Searching确定增量搜索是否已经结束。
扩展：
1、增量搜索类：TIncreSearch只是一个默认的搜索实现类，这不是一个最快速的类，
如果你知道如何更快速的实现增量搜索，请实现IIncreSearch接口，并在处理器
的构造函数中传进这个类，比如：
TSomeInsreSearchHandler.Create(TSomeControl, YourIncreSearch);
处理器面对的是搜索接口，因此要特别注意其生命周期的管理。
2、搜索处理器：TEditInsreSearchHandler只能处理TCustomEdit的编辑控件，对于一
些不是从TCustomEdit继承的控件，则必须写另外的处理器。
实现很简单，继承TInsreSearchHandler，并且必须覆盖GetSearchStr，GetSearchStart，
SetMatchBlock三个抽象方法，提供搜索必需的信息。
如想提供更多的扩展，可以覆盖TInsreSearchHandler其他的虚方法。
******************************************************************************)
interface
uses
Classes, Messages, Controls, Contnrs;
type
{ 匹配的块 }
PMatchBlock = ^TMatchBlock;
TMatchBlock = record
Start: Integer;
Len: Integer;
end;
{ 增量搜索接口 }
IIncreSearch = interface
['{A8037752-ED93-49F6-915C-6D8E82ADD631}']
(* 开始搜索 *)
procedure StartSearch(const SearchStr: string; Start: Integer = 0; MaxKey: Word = 80);
(* 结束搜索 *)
procedure EndSearch;
(* 增加一个字符 *)
function IncreaseChar(C: Char): PMatchBlock;
(* 减少一个字符 *)
function DecreaseChar: PMatchBlock;
(* 是否正在搜索 *)
function GetSearching: Boolean;
property Searching: Boolean read GetSearching;
end;
{ 增量搜索的默认实现：利用栈来保存匹配块 }
TIncreSearch = class(TInterfacedObject, IIncreSearch)
private
FSearching: Boolean;
FKeyIndex: Integer;
FStart: Integer;
FSearchKey: string;
FSearchStr: string;
FMatchBlockList: TStack;
protected
procedure ClearMatchBlockList;
public
procedure StartSearch(const SearchStr: string; Start: Integer = 0; MaxKey: Word = 80);
procedure EndSearch;
function IncreaseChar(C: Char): PMatchBlock;
function DecreaseChar: PMatchBlock;
function GetSearching: Boolean;
property Searching: Boolean read GetSearching;
constructor Create;
destructor Destroy; override;
end;
{ 增量搜索处理器，抽象类 }
TIncreSearchHandler = class
private
FIncreSearch: IIncreSearch;
protected
FCtrl: TControl;
FOldCtrlWndProc: TWndMethod;
procedure HookWndProc;
procedure UnHookWndProc;
(* 控件处理过程，处理增量搜索的字符 *)
procedure CtrlWndProc(var Message: TMessage); virtual;
(* 导致增量搜索结束的消息 *)
function IsEndSearchMsg(Message: TMessage): Boolean; virtual;
(* 取得等搜索的字符串，必须由子类给出 *)
function GetSearchStr: string; virtual; abstract;
(* 取得搜索的起始位置，必须由子类给出 *)
function GetSearchStart: Integer; virtual; abstract;
(* 返回搜索关键字的最大长度 *)
function GetMaxKey: Integer; virtual;
(* 设置搜到的匹配块，必须由子类实现 *)
procedure SetMatchBlock(MatchBlock: PMatchBlock); virtual; abstract;
(* 开始搜索，子类作额外处理 *)
procedure DoEndSearch; virtual;
(* 结束搜索，子类作额外处理 *)
procedure DoStartSearch; virtual;
public
procedure StarteSearch;
procedure EndSearch;
function Searching: Boolean;
property Ctrl: TControl read FCtrl;
constructor Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil); virtual;
destructor Destroy; override;
end;
{ 编辑控件增量搜索处理器，编辑控件必须从TCustomEdit继承 }
TEdtIncreSearchHandler = class(TIncreSearchHandler)
protected
function GetSearchStr: string; override;
procedure SetMatchBlock(MatchBlock: PMatchBlock); override;
function GetSearchStart: Integer; override;
public
constructor Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil); override;
end;
implementation
uses
SysUtils, StdCtrls, Windows;
{ TIncreSearch }
procedure TIncreSearch.ClearMatchBlockList;
var
P: Pointer;
begin
if FMatchBlockList.Count > 0 then
begin
P := FMatchBlockList.Pop;
Dispose(P);
end;
while FMatchBlockList.Count > 0 do
begin
P := FMatchBlockList.Pop;
Dispose(P);
end;
end;
constructor TIncreSearch.Create;
begin
FMatchBlockList := TStack.Create;
end;
function TIncreSearch.DecreaseChar: PMatchBlock;
begin
Result := nil;
if FKeyIndex = 0 then Exit;
FSearchKey[FKeyIndex] := #0;
Dec(FKeyIndex);
if FMatchBlockList.Count > 1 then
Dispose(FMatchBlockList.Pop);
if FMatchBlockList.Count > 0 then
Result := PMatchBlock(FMatchBlockList.Peek);
end;
destructor TIncreSearch.Destroy;
begin
ClearMatchBlockList;
FMatchBlockList.Free;
inherited;
end;
procedure TIncreSearch.EndSearch;
begin
FSearching := False;
end;
function TIncreSearch.GetSearching: Boolean;
begin
Result := FSearching;
end;
function TIncreSearch.IncreaseChar(C: Char): PMatchBlock;
var
nStart: Integer;
pwSearStr, pwMatch: PChar;
begin
Result := nil;
Inc(FKeyIndex);
if FKeyIndex > Length(FSearchKey) then Exit;
if (C >= 'A') and (C <= 'Z') then
C := Chr(Ord(C) + $20);
FSearchKey[FKeyIndex] := C;
if FMatchBlockList.Count = 1 then
nStart := FStart
else
nStart := PMatchBlock(FMatchBlockList.Peek)^.Start;
pwSearStr := PChar(FSearchStr);
Inc(pwSearStr, nStart);
pwMatch := StrPos(pwSearStr, PChar(FSearchKey));
if pwMatch <> nil then
begin
New(Result);
Result^.Len := FKeyIndex;
Result^.Start := nStart + (pwMatch - pwSearStr);
FMatchBlockList.Push(Result);
end
else begin
FSearchKey[FKeyIndex] := #0;
Dec(FKeyIndex);
end;
end;
procedure TIncreSearch.StartSearch(const SearchStr: string;
Start: Integer; MaxKey: Word);
var
SearBlock: PMatchBlock;
pStr: PChar;
begin
FSearching := True;
//初始化关键字
SetLength(FSearchKey, MaxKey);
FillChar(FSearchKey[1], MaxKey, 0);
FKeyIndex := 0;
FStart := Start;
//字符串流全部变成小写
FSearchStr := SearchStr;
pStr := PChar(FSearchStr);
StrLower(pStr);
//压入一个起始位置的匹配块
ClearMatchBlockList;
New(SearBlock);
SearBlock^.Start := FStart;
SearBlock^.Len := 0;
FMatchBlockList.Push(SearBlock);
end;
{ TIncreSearchHandler }
constructor TIncreSearchHandler.Create(ACtrl: TControl; IncreSearch: IIncreSearch = nil);
begin
FCtrl := ACtrl;
HookWndProc;
if IncreSearch = nil then
FIncreSearch := TIncreSearch.Create
else
FIncreSearch := IncreSearch;
end;
procedure TIncreSearchHandler.CtrlWndProc(var Message: TMessage);
var
MatchBlock: PMatchBlock;
C: Char;
Key: Word;
begin
if FIncreSearch.Searching then
begin
if IsEndSearchMsg(Message) then
begin
FIncreSearch.EndSearch;
DoEndSearch;
end
else begin
//处理增量搜索的字符
case Message.Msg of
WM_CHAR:
begin
C := Char(TWMChar(Message).CharCode);
if C <> #8 then
begin
MatchBlock := FIncreSearch.IncreaseChar(C);
if MatchBlock <> nil then
SetMatchBlock(MatchBlock);
end;
TWMChar(Message).CharCode := 0;
end;
WM_KEYDOWN:
begin
Key := TWMKey(Message).CharCode;
if Key = 8 then
begin
MatchBlock := FIncreSearch.DecreaseChar;
TWMKey(Message).CharCode := 0;
if MatchBlock <> nil then
SetMatchBlock(MatchBlock);
end;
end;
end;
end;
end;
FOldCtrlWndProc(Message);
end;
destructor TIncreSearchHandler.Destroy;
begin
UnHookWndProc;
FIncreSearch := nil;
inherited;
end;
procedure TIncreSearchHandler.DoEndSearch;
begin
end;
procedure TIncreSearchHandler.DoStartSearch;
begin
end;
procedure TIncreSearchHandler.EndSearch;
begin
FIncreSearch.EndSearch;
end;
function TIncreSearchHandler.GetMaxKey: Integer;
begin
Result := 80;
end;
procedure TIncreSearchHandler.HookWndProc;
begin
FOldCtrlWndProc := FCtrl.WindowProc;
FCtrl.WindowProc := CtrlWndProc;
end;
function TIncreSearchHandler.IsEndSearchMsg(Message: TMessage): Boolean;
function KeyInKeys(Key: Word): Boolean;
begin
case Key of
VK_ESCAPE, VK_RIGHT, VK_LEFT, VK_UP, VK_DOWN, VK_TAB,
VK_RETURN, VK_INSERT:
Result := True
else
Result := False;
end;
end;
begin
Result := ((Message.Msg >= WM_MOUSEFIRST) and (Message.Msg <= WM_MOUSELAST) and
(Message.Msg <> WM_MOUSEMOVE)) or
((Message.Msg = WM_KEYDOWN) and KeyInKeys(TWMKey(Message).CharCode));
end;
function TIncreSearchHandler.Searching: Boolean;
begin
Result := FIncreSearch.Searching;
end;
procedure TIncreSearchHandler.StarteSearch;
begin
FIncreSearch.StartSearch(GetSearchStr, GetSearchStart, GetMaxKey);
end;
procedure TIncreSearchHandler.UnHookWndProc;
begin
FCtrl.WindowProc := FOldCtrlWndProc;
end;
{ TEdtIncreSearchHandler }
constructor TEdtIncreSearchHandler.Create(ACtrl: TControl;
IncreSearch: IIncreSearch);
begin
inherited;
if not (ACtrl is TCustomEdit) then
raise Exception.Create('the control must be inherited from TCustomEdit');
end;
function TEdtIncreSearchHandler.GetSearchStart: Integer;
begin
if (Ctrl is TCustomEdit) then
Result := TCustomEdit(Ctrl).SelStart
else
Result := 0;
end;
function TEdtIncreSearchHandler.GetSearchStr: string;
begin
if FCtrl is TCustomEdit then
Result := TCustomEdit(Ctrl).Text
else
Result := '';
end;
procedure TEdtIncreSearchHandler.SetMatchBlock(MatchBlock: PMatchBlock);
begin
if (FCtrl is TCustomEdit) and (MatchBlock <> nil) then
begin
TCustomEdit(Ctrl).SelStart := MatchBlock^.Start;
TCustomEdit(Ctrl).SelLength := MatchBlock^.Len;
end;
end;
end.
结束
为了说明这个单元的使用，这里有例子程序下载。
你也可以实现单元的接口或扩展某些类，以满足你的需求。
