画图学习 [5] TextRect

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    btn1: TButton;
    btn2: TButton;
    btn3: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
    procedure btn3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
const
  s: string = 'LJj的Delphi博客';
  r: TRect = (Left:0; Top:0; Right:60; Bottom:60);
begin
  Canvas.Brush.Color := clWhite;
  Canvas.FillRect(r);
  Canvas.TextRect(r, 10, 10, s);
end;

procedure TForm1.btn2Click(Sender: TObject);
var
  r: TRect;
  s: string;
begin
  r := ClientRect;
  InflateRect(r, -100, -10);

  s := 'LJj的Delphi博客';
  Canvas.Brush.Color := clYellow;
  Canvas.FillRect(r);
  Canvas.TextRect(r,s);

end;

procedure TForm1.btn3Click(Sender: TObject);
var
  r: TRect;
  s: string;
begin
  r.Left := 350;
  r.Top := 10;
  r.Right := 720;
  r.Bottom := 100;

  s := 'LJj的Delphi博客';
  Canvas.Brush.Color := clGreen;
  Canvas.FillRect(r);
  Canvas.TextRect(r, s, [tfCenter, tfVerticalCenter, tfSingleLine]);
end;

end.

TextRect(
   var Rect: TRect;             {矩形范围}
  var Text: string;            {文本}
  TextFormat: TTextFormat = [] {选项; 集合类型, 默认值是个空的集合}
);

{参数三是 TTextFormat 类型的集合, 它定义如下:}
TTextFormat = set of TTextFormats;

{TTextFormats 是个枚举, 定义如下}
TTextFormats = (tfBottom, tfCalcRect, tfCenter, tfEditControl, tfEndEllipsis,
  tfPathEllipsis, tfExpandTabs, tfExternalLeading, tfLeft, tfModifyString,
  tfNoClip, tfNoPrefix, tfRight, tfRtlReading, tfSingleLine, tfTop,
  tfVerticalCenter, tfWordBreak);

{所以参数三可以是下列值之一或它们的组合}
tfBottom         
tfCalcRect
tfCenter
tfEditControl
tfEndEllipsis
tfPathEllipsis
tfExpandTabs
tfExternalLeading
tfLeft
tfModifyString
tfNoClip
tfNoPrefix
tfRight
tfRtlReading
tfSingleLine
tfTop
tfVerticalCenter
tfWordBreak