//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: