WinAPI 字符及字符串函数(14): CharToOem、OemToChar
CharToOemBuff、OemToCharBuff 与 CharToOem、OemToChar 的区别只是前者可以指定要转换的字符数.
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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;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
Buf: PWideChar;
AnsiBuf: array[0..255] of AnsiChar;
begin
Buf := '万一的 Delphi 博客';
CharToOem(Buf, AnsiBuf);
ShowMessage(string(AnsiBuf)); {万一的 Delphi 博客}

FillChar(AnsiBuf, Length(AnsiBuf), #0);

CharToOemBuff(Buf, AnsiBuf, 6);
ShowMessage(string(AnsiBuf)); {万一的 De}
end;

procedure TForm1.Button2Click(Sender: TObject);
var
str: string;
p: PAnsiChar;
begin
str := '万一的 Delphi 博客';

p := GetMemory(256);
CharToOem(PChar(str), p);
ShowMessage(string(p)); {万一的 Delphi 博客}
FreeMemory(p);

p := GetMemory(256);
CharToOemBuff(PChar(str), p, 6);
ShowMessage(string(p)); {万一的 De}
FreeMemory(p);
end;

procedure TForm1.Button3Click(Sender: TObject);
var
AnsiBuf: PAnsiChar;
Buf: array[0..255] of Char;
begin
AnsiBuf := '万一的 Delphi 博客';
OemToChar(AnsiBuf, buf);
ShowMessage(string(Buf)); {万一的 Delphi 博客}

FillChar(Buf, Length(Buf), #0);

OemToCharBuff(AnsiBuf, buf, 6);
ShowMessage(string(Buf)); {万一的}
end;

procedure TForm1.Button4Click(Sender: TObject);
var
AnsiStr: AnsiString;
p: PChar;
begin
AnsiStr := '万一的 Delphi 博客';

p := StrAlloc(256);
OemToChar(PAnsiChar(AnsiStr), p);
ShowMessage(string(p)); {万一的 Delphi 博客}
StrDispose(p);

p := StrAlloc(256);
OemToCharBuff(PAnsiChar(AnsiStr), p, 6);
ShowMessage(string(p)); {万一的}
StrDispose(p);
end;

end.