//第一种重载的声明:
TextRect(Rect: TRect;       {矩形}X, Y: Integer;     {相对于窗体的位置}const Text: string {文本}
);{如果要输出的文本超出指定的矩形将不被显示}//第一种重载的举例:
procedure TForm1.Button1Click(Sender: TObject);
constR: TRect = (Left:0; Top:0; Right:60; Bottom:60);s = '万一的 Delphi 博客';
beginCanvas.Brush.Color := clWhite;Canvas.FillRect(R);Canvas.TextRect(R, 10, 10, s);
end;//效果图:

//第二种重载的声明:
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//这个函数是 API 函数 DrawTextEx 的简化, 可以参见: DrawTextEx//第二种重载的举例1:{默认是顶对齐、左对齐; 前两个参数都是传址的, 不能用常量}
procedure TForm1.FormPaint(Sender: TObject);
varR: TRect;S: string;
beginR := ClientRect;InflateRect(R,-10,-10); {把矩形缩小一圈}S := 'Delphi';Canvas.Brush.Color := clWhite;Canvas.FillRect(R);Canvas.TextRect(R, S);
end;//效果图:

//第二种重载的举例2:{单行文本、水平居中、垂直居中}
procedure TForm1.FormPaint(Sender: TObject);
varR: TRect;S: string;
beginR := ClientRect;InflateRect(R,-10,-10); {把矩形缩小一圈}S := 'Delphi';Canvas.Brush.Color := clWhite;Canvas.FillRect(R);Canvas.TextRect(R, S , [tfSingleLine, tfCenter, tfVerticalCenter]);
end;//效果图: