Delphi 與 DirectX 之 DelphiX(26): TDIB 的主要載體 – TDXPaintBox

TDXPaintBox 和 TPaintBox 一樣擁有重要的屬性 Canvas;

現在要關心的是 TDXPaintBox 另一個主要屬性: DIB(TDIB 對象);
在下面學習 TDIB 時, 應該會大量用到這個 TDXPaintBox.

雖然叫它 TDXPaintBox, 但我覺得它更像 TImage, 只是把 TImage.Picture 換做了 TDXPaintBox.DIB.

在設計時可以給 TDXPaintBox 的 DIB 對象添加圖片, 不過本例是運行時添加的; 運行:

另外, 這是本例中的圖片, 應右鍵另存到 C:\Temp\DX.jpg :

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, DIB, StdCtrls;type  TForm1 = class(TForm)    DXPaintBox1: TDXPaintBox;    Button1: TButton;    Button2: TButton;    Button3: TButton;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}var  w,h: Integer;procedure TForm1.Button1Click(Sender: TObject);begin  DXPaintBox1.Width := w div 2;  DXPaintBox1.Height := w div 2;end;procedure TForm1.Button2Click(Sender: TObject);begin  DXPaintBox1.Width := ClientWidth;  DXPaintBox1.Height := ClientHeight;end;procedure TForm1.Button3Click(Sender: TObject);begin  DXPaintBox1.Width := w;  DXPaintBox1.Height := h;end;procedure TForm1.FormCreate(Sender: TObject);const  ImgPath1 = 'C:\Temp\DX.jpg';begin  DXPaintBox1.Left := 0;  DXPaintBox1.Top := 0;  DXPaintBox1.DIB.LoadFromFile(ImgPath1); {!}  w := DXPaintBox1.DIB.Width;  h := DXPaintBox1.DIB.Height;  DXPaintBox1.Width := w;  DXPaintBox1.Height := h;  DXPaintBox1.Stretch := True;end;end.

表單檔案:

object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 165  ClientWidth = 225  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  OnCreate = FormCreate  PixelsPerInch = 96  TextHeight = 13  object DXPaintBox1: TDXPaintBox    Left = 8    Top = 8    Width = 81    Height = 73    AutoStretch = False    Center = False    KeepAspect = False    Stretch = False    ViewWidth = 0    ViewHeight = 0  end  object Button1: TButton    Left = 23    Top = 132    Width = 60    Height = 25    Caption = 'Button1'    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 89    Top = 132    Width = 60    Height = 25    Caption = 'Button2'    TabOrder = 1    OnClick = Button2Click  end  object Button3: TButton    Left = 157    Top = 132    Width = 60    Height = 25    Caption = 'Button3'    TabOrder = 2    OnClick = Button3Click  endend