GdiPlus[43]: IGPGraphics (二) 关于文本绘制

IGPGraphics 中绘制文本相关的方法和属性:

---

IGPGraphics.DrawString();             { 绘制文本 }

IGPGraphics.MeasureString();          { 获取指定格式的字符串需要的矩形 }



IGPGraphics.MeasureCharacterRanges(); { 获取指定字符所在的区域 }



IGPGraphics.DrawDriverString();       { 绘制可指定间距的文本 }

IGPGraphics.MeasureDriverString();    { 获取可指定间距文本所需要的矩形范围 }



IGPGraphics.TextRenderingHint;        { 获取或设置文本呈现模式 }

IGPGraphics.TextContrast;             { 灰度校正值(消除锯齿和 ClearType 文本的伽玛值校正: 0..12, 默认是 4) }




 
   

DrawString 的三种用法:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  str: string;

  Font: IGPFont;

  Pt: TGPPointF;

  Brush: IGPSolidBrush;

  StringFormat: IGPStringFormat;

  Rect: TGPRectF;

begin

  Graphics := TGPGraphics.Create(Handle);

  //

  str := 'Delphi 2010';

  Font := TGPFont.Create('Arial Black', 16);

  Pt.Initialize(0, 10);

  Brush := TGPSolidBrush.Create($FF228B22);

  Graphics.DrawString(str, Font, Pt, Brush);

  //

  Pt.X := ClientWidth;

  Brush.Color := $FF0000FF;

  StringFormat := TGPStringFormat.Create([StringFormatFlagsDirectionRightToLeft]);

  Graphics.DrawString(str, Font, Pt, StringFormat, Brush);

  //

  Brush.Color := $FFFF0000;

  Rect.Initialize(0, 0, ClientWidth, ClientHeight);

  StringFormat.FormatFlags := [StringFormatFlagsDirectionVertical];

  StringFormat.Alignment := StringAlignmentCenter;

  StringFormat.LineAlignment := StringAlignmentCenter;

  Graphics.DrawString(str, Font, Rect, StringFormat, Brush);

end;


 
   

MeasureString 测试:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  str: string;

  Font: IGPFont;

  Pt: TGPPointF;

  Brush: IGPSolidBrush;

  Pen: IGPPen;

  StringFormat: IGPStringFormat;

  Rect, MeasureRect: TGPRectF;

begin

  Graphics := TGPGraphics.Create(Handle);

  Graphics.Clear($FFFFFFFF);

  Brush := TGPSolidBrush.Create($FF228B22);

  Pen := TGPPen.Create($FF000000);

  //

  str := 'Delphi 2010';

  Font := TGPFont.Create('Arial Black', 16);

  Pt.Initialize(10, 10);



  Graphics.DrawString(str, Font, Pt, Brush);

  MeasureRect := Graphics.MeasureString(str, Font, Pt, nil);

  Graphics.DrawRectangle(Pen, MeasureRect);



  //

  Brush.Color := $FFFF0000;

  Rect.Initialize(0, 0, ClientWidth, ClientHeight);

  StringFormat := TGPStringFormat.Create;

  StringFormat.Alignment := StringAlignmentCenter;

  StringFormat.LineAlignment := StringAlignmentCenter;



  Graphics.DrawString(str, Font, Rect, StringFormat, Brush);

  MeasureRect := Graphics.MeasureString(str, Font, Rect, StringFormat);

  Graphics.DrawRectangle(Pen, MeasureRect);

end;


 
   

SetMeasurableCharacterRanges 测试:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  str: string;

  Font: IGPFont;

  CharRange1,CharRange2: TGPCharacterRange;

  CharRanges: IGPCharacterRanges;

  Rect: TGPRectF;

  StringFormat: IGPStringFormat;

  Brush,BrushBack: IGPBrush;

  Regions: IGPRegions;

  R1,R2: TGPRectF;

begin

  Graphics := TGPGraphics.Create(Handle);

  str := '万一的 Delphi 博客';

  Font := TGPFont.Create('微软雅黑', 20);

  Brush := TGPSolidBrush.Create($FFFF0000);

  BrushBack := TGPSolidBrush.Create($FFC0C0C0);



  CharRanges := TGPArray<TGPCharacterRange>.Create(2);

  CharRange1.Initialize(0, 2);

  CharRange2.Initialize(4, 6);

  CharRanges[0] := CharRange1;

  CharRanges[1] := CharRange2;



  StringFormat := TGPStringFormat.Create;

  StringFormat.SetMeasurableCharacterRanges(Charranges);



  Rect.Initialize(20, 20, ClientWidth, ClientHeight);



  Regions := Graphics.MeasureCharacterRanges(str, Font, Rect, StringFormat);

  Regions[0].GetBounds(R1, Graphics);

  Regions[1].GetBounds(R2, Graphics);

  Graphics.FillRectangle(BrushBack, R1);

  Graphics.FillRectangle(BrushBack, R2);



  Graphics.DrawString(str, Font, Rect.Location, Brush);

end;


 
   

DrawDriverString 测试:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Font: IGPFont;

  Brush: IGPSolidBrush;

  Pts: array of TGPPointF;

  str: string;

  i: Integer;

begin

  Graphics := TGPGraphics.Create(Canvas.Handle);

  Brush := TGPSolidBrush.Create($FF8A2BE2);



  str := 'ABCDEFG';

  SetLength(Pts, Length(str));

  for i := 0 to Length(str) - 1 do

  begin

    Pts[i].X := i * 50 + 20;

    Pts[i].Y := 60;

  end;



  Font := TGPFont.Create('Arial Black', 32);

  Graphics.DrawDriverString(PUint16(PChar(str)),

                            Length(str),

                            Font,

                            Brush,

                            @Pts[0],

                            [DriverStringOptionsCmapLookup],

                            nil

  );

end;


 
   

IGPGraphics.TextRenderingHint 测试:

---

{

TextRenderingHintSystemDefault            // 使用字体的默认设置

TextRenderingHintSingleBitPerPixelGridFit // 符号位图 + hinting 技术(改善字符主干和弯曲部分)

TextRenderingHintSingleBitPerPixel        // 符号位图(不使用 hinting 技术时字体会更宽一些)

TextRenderingHintAntiAliasGridFit         // 消除锯齿 + hinting 技术

TextRenderingHintAntiAlias                // 消除锯齿

TextRenderingHintClearTypeGridFit         // ClearType 文本 + hinting 技术

}



uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Brush: IGPSolidBrush;

  Font: IGPFont;

  Pt: TGPPointF;

begin

  Graphics := TGPGraphics.Create(Handle);

  Brush := TGPSolidBrush.Create($FFB22222);

  Font := TGPFont.Create('Arial Black', 24);



  Pt.Initialize(10, 10);

  Graphics.TextRenderingHint := TextRenderingHintSystemDefault;

  Graphics.DrawString('SystemDefault', Font, Pt, Brush);



  Pt.Y := Pt.Y + Font.GetHeight(Graphics) + 10;

  Graphics.TextRenderingHint := TextRenderingHintSingleBitPerPixelGridFit;

  Graphics.DrawString('SingleBitPerPixelGridFit', Font, Pt, Brush);



  Pt.Y := Pt.Y + Font.GetHeight(Graphics) + 10;

  Graphics.TextRenderingHint := TextRenderingHintSingleBitPerPixel;

  Graphics.DrawString('SingleBitPerPixel', Font, Pt, Brush);



  Pt.Y := Pt.Y + Font.GetHeight(Graphics) + 10;

  Graphics.TextRenderingHint := TextRenderingHintAntiAliasGridFit;

  Graphics.DrawString('AntiAliasGridFit', Font, Pt, Brush);



  Pt.Y := Pt.Y + Font.GetHeight(Graphics) + 10;

  Graphics.TextRenderingHint := TextRenderingHintAntiAlias;

  Graphics.DrawString('AntiAlias', Font, Pt, Brush);



  Pt.Y := Pt.Y + Font.GetHeight(Graphics) + 10;

  Graphics.TextRenderingHint := TextRenderingHintClearTypeGridFit;

  Graphics.DrawString('ClearTypeGridFit', Font, Pt, Brush);

end;


 
   

//后接 "关于文本绘制续"