WinAPI: SetTextAlign - 设置绘图环境的文本对齐方式

//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;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ExtCtrls;



type

  TForm1 = class(TForm)

    RadioGroup1: TRadioGroup;

    RadioGroup2: TRadioGroup;

    procedure FormPaint(Sender: TObject);

    procedure RadioGroup1Click(Sender: TObject);

    procedure RadioGroup2Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  H: Cardinal = 0;

  V: Cardinal = 0;



procedure TForm1.FormPaint(Sender: TObject);

var

  dc: HDC;

  x,y: Integer;

const

  str = '万一的 Delphi 博客';

begin

  dc := 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);

begin

  case RadioGroup1.ItemIndex of

    0: H := TA_LEFT;

    1: H := TA_CENTER;

    2: H := TA_RIGHT;

  end;

  Self.Repaint;

end;



procedure TForm1.RadioGroup2Click(Sender: TObject);

begin

  case RadioGroup2.ItemIndex of

    0: V := TA_TOP;

    1: V := VTA_CENTER;

    2: V := TA_BOTTOM;

  end;

  Self.Repaint;

end;



end.




 
   




//效果图:

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