调整 TEdit 文本对齐

譬如让 Edit1 文本右对齐:
SetWindowLong(Edit1.Handle, GWL_STYLE, GetWindowLong(Edit1.Handle, GWL_STYLE) or ES_RIGHT);

---

本例效果图:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    RadioGroup1: TRadioGroup;
    procedure FormCreate(Sender: TObject);
    procedure RadioGroup1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  RadioGroup1.Items.CommaText := 'Left,Center,Right';
  RadioGroup1.ItemIndex := 0;
end;

procedure TForm1.RadioGroup1Click(Sender: TObject);
var
  es: Integer;
begin
  es := GetWindowLong(Edit1.Handle, GWL_STYLE) or 3;
  es := es xor (3 - RadioGroup1.ItemIndex);
  SetWindowLong(Edit1.Handle, GWL_STYLE, es);
  Edit1.Refresh;
end;

end.

这里面有个问题需要知道: 决定对齐方式的三个常量值 ES_LEFT、ES_CENTER、ES_RIGHT 分别是 0、1、2, 刚好可以对应 RadioGroup1.ItemIndex; 再换一种思路实现一下:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    RadioGroup1: TRadioGroup;
    procedure FormShow(Sender: TObject);
    procedure RadioGroup1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  es_bak: Integer;

procedure TForm1.FormShow(Sender: TObject);
begin
  RadioGroup1.Items.CommaText := 'Left,Center,Right';
  es_bak := GetWindowLong(Edit1.Handle, GWL_STYLE);
end;

procedure TForm1.RadioGroup1Click(Sender: TObject);
var
  es: Integer;
begin
  es := es_bak or RadioGroup1.ItemIndex;
  SetWindowLong(Edit1.Handle, GWL_STYLE, es);
  Edit1.Refresh;
end;

end.