WinAPI 字符及字符串函数(13): lstrcmp、lstrcmpi - 对比串
lstrcmp 区分大小写; lstrcmpi 不区分大小写. 返回值: -1、0、1, 其中 0 表示相同.
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unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
Button5: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure Button5Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

const
Msgs: array[-1..1] of Char = ('<', '=', '>');

procedure TForm1.Button1Click(Sender: TObject);
var
p1,p2: PChar;
n: Integer;
begin
p1 := 'A';
p2 := 'B';

n := lstrcmp(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {A < B}

n := lstrcmpi(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {A < B}
end;

procedure TForm1.Button2Click(Sender: TObject);
var
p1,p2: PChar;
n: Integer;
begin
p1 := 'A';
p2 := 'a';

n := lstrcmp(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {A > a}

n := lstrcmpi(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {A = a}
end;

procedure TForm1.Button3Click(Sender: TObject);
var
p1,p2: PChar;
n: Integer;
begin
p1 := 'ABC';
p2 := 'abcd';

n := lstrcmp(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {ABC < abcd}

n := lstrcmpi(p1, p2);
ShowMessageFmt('%s %s %s', [p1, Msgs[n], p2]); {ABC < abcd}
end;

{这和 Delphi 的 CompareStr、CompareText 区别还是很大}
procedure TForm1.Button4Click(Sender: TObject);
var
p1,p2: PChar;
n: Integer;
begin
p1 := 'A';
p2 := 'a';

n := CompareStr(p1, p2);
ShowMessage(IntToStr(n)); {-32}

n := CompareText(p1, p2);
ShowMessage(IntToStr(n)); {0}
end;

{和 StrComp、StrIComp、StrLComp、StrLIComp 也不一样}
procedure TForm1.Button5Click(Sender: TObject);
var
p1,p2: PChar;
n: Integer;
begin
p1 := 'A';
p2 := 'a';

n := StrComp(p1, p2);
ShowMessage(IntToStr(n)); {-32}

n := StrIComp(p1, p2);
ShowMessage(IntToStr(n)); {0}

n := StrLComp(p1, p2, 1);
ShowMessage(IntToStr(n)); {-32}

n := StrLIComp(p1, p2, 1);
ShowMessage(IntToStr(n)); {0}
end;

end.