//声明:
SetTextAlign(DC: HDC;    {设备环境句柄}Flags: UINT {对齐选项}
): UINT;      {返回对齐选项值; 如果返回 GDI_ERROR 表示设置失败}//Flags 参数的可选值:
TA_NOUPDATECP = 0;    {每一次文本输出后, 不更新当前位置}
TA_UPDATECP   = 1;    {每一次文本输出后, 更新当前位置}
TA_LEFT       = 0;    {起始于文本外接矩形左边}
TA_RIGHT      = 2;    {起始于文本外接矩形右边}
TA_CENTER     = 6;    {起始于文本外接矩形的水平中心}
TA_TOP        = 0;    {起始于文本外接矩形顶边}
TA_BOTTOM     = 8;    {起始于文本外接矩形底边}
TA_BASELINE   = 24;   {起始于文本基线}
TA_RTLREADING = $100; {文本顺序从右到左, 只对特殊语种}VTA_BASELINE  = TA_BASELINE; {垂直基线}
VTA_LEFT      = TA_BOTTOM;
VTA_RIGHT     = TA_TOP;
VTA_CENTER    = TA_CENTER;   {垂直居中}
VTA_BOTTOM    = TA_RIGHT;
VTA_TOP       = TA_LEFT;//举例:
unit Unit1;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls, ExtCtrls;typeTForm1 = class(TForm)RadioGroup1: TRadioGroup;RadioGroup2: TRadioGroup;procedure FormPaint(Sender: TObject);procedure RadioGroup1Click(Sender: TObject);procedure RadioGroup2Click(Sender: TObject);end;varForm1: TForm1;implementation{$R *.dfm}varH: Cardinal = 0;V: Cardinal = 0;procedure TForm1.FormPaint(Sender: TObject);
vardc: HDC;x,y: Integer;
conststr = '万一的 Delphi 博客';
begindc := Canvas.Handle;x := ClientWidth div 2;y := ClientHeight div 2;SetTextAlign(dc, H or V);TextOut(dc, x, y, str, Length(str));
end;procedure TForm1.RadioGroup1Click(Sender: TObject);
begincase RadioGroup1.ItemIndex of0: H := TA_LEFT;1: H := TA_CENTER;2: H := TA_RIGHT;end;Self.Repaint;
end;procedure TForm1.RadioGroup2Click(Sender: TObject);
begincase RadioGroup2.ItemIndex of0: V := TA_TOP;1: V := VTA_CENTER;2: V := TA_BOTTOM;end;Self.Repaint;
end;end.//效果图: