再学 GDI+[20]: TGPTextureBrush 与 TWrapMode

TGPTextureBrush.Create(
  image: TGPImage;                   {用于画刷的图像}
  wrapMode: TWrapMode = WrapModeTile {平铺样式, 是可选值, 见下表}
);

本例效果图:

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代码文件:

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unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ComboBox1: TComboBox;
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses GDIPOBJ, GDIPAPI, TypInfo;

procedure TForm1.FormCreate(Sender: TObject);
var
  i: Integer;
begin
  for i := 0 to 4 do
    ComboBox1.Items.Add(GetEnumName(TypeInfo(TWrapMode), i));
  ComboBox1.ItemIndex := 0;
end;

procedure TForm1.FormPaint(Sender: TObject);
var
  g: TGPGraphics;
  r: TGPRect;
  img: TGPImage;
  tb: TGPTextureBrush;
begin
  g := TGPGraphics.Create(Canvas.Handle);
  r := MakeRect(ClientRect);

  img := TGPImage.Create('c:\temp\cat.png');
  tb := TGPTextureBrush.Create(img);

  tb.SetWrapMode(TWrapMode(ComboBox1.ItemIndex));
  g.FillRectangle(tb, r);

  img.Free;
  tb.Free;
  g.Free;
end;

procedure TForm1.ComboBox1Change(Sender: TObject);
begin
  Repaint;
end;

end.

窗体文件:

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object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 263
  ClientWidth = 352
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  Position = poDesktopCenter
  OnCreate = FormCreate
  OnPaint = FormPaint
  PixelsPerInch = 96
  TextHeight = 13
  object ComboBox1: TComboBox
    Left = 242
    Top = 2
    Width = 107
    Height = 21
    ItemHeight = 13
    TabOrder = 0
    Text = 'ComboBox1'
    OnChange = ComboBox1Change
  end
end

WrapMode 选项:

Delphi	微软	说明
WrapModeTile	Tile	平铺渐变或纹理。
WrapModeTileFlipX	TileFlipX	水平反转纹理或渐变，然后平铺该纹理或渐变。
WrapModeTileFlipY	TileFlipY	垂直反转纹理或渐变，然后平铺该纹理或渐变。
WrapModeTileFlipXY	TileFlipXY	水平和垂直反转纹理或渐变，然后平铺该纹理或渐变。
WrapModeClamp	Clamp	纹理或渐变没有平铺。

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