API图像函数(delphi).doc

WinAPI: ExtractIcon - 获取 EXE、DLL 或 ICO 文件中的图标 /声明:ExtractIcon( hInst: HINST; 调用函数的程序实例 lpszExeFileName: PChar; 文件路径; 文件可以是 *.exe、*.dll、*.ico nIconIndex: UINT 图标索引): HICON; 返回图标句柄; 索引为 0 时返回第一个图标句柄; 索引为 #FFFFFFFF 时返回图标总数/举例:unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmuses ShellAPI; ExtractIcon 在其中声明procedure TForm1.Button1Click(Sender: TObject);var ico: TIcon; i,count,x,y,w,h: Integer; FilePath: string;begin 随便找了个路径, 如果缺失会退出 FilePath := C:Program FilesMacromediaFireworks 8Fireworks.exe; if not FileExists(FilePath) then begin ShowMessage(文件不存在); Exit; end; ico := TIcon.Create; x := 10; y := 10; w := 0; h := 0; Repaint; 先算出文件内的图标总数 count := ExtractIcon(HInstance, PChar(FilePath), HICON(-1); for i := 0 to count - 1 do begin 循环提取图标 ico.Handle := ExtractIcon(HInstance, PChar(FilePath), i); 画出图标 Canvas.Draw(x,y,ico); 下面只是调整显示位置 if w ico.Width then w := ico.Width; if h = ClientWidth - w then begin x := 10; y := y + h + 10; end; end; ico.Free;end;end./效果图:WinAPI: LoadBitmap - 从资源中载入位图 /声明:LoadBitmap( hInstance: HINST; EXE 或 DLL 的句柄 lpBitmapName: PChar 资源标识符): HBITMAP; 返回位图句柄这里有示例 WinAPI: LoadCursor - 从资源中载入光标 /声明:LoadCursor( hInstance: HINST; EXE 或 DLL 的句柄, 0 表示载入系统资源 lpCursorName: PChar 资源标识符): HCURSOR; 返回光标句柄这里有示例 /调用系统光标的例子:unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmprocedure TForm1.Button1Click(Sender: TObject);var cur: TIcon;begin cur := TIcon.Create; cur.Handle := LoadCursor(0, IDC_HAND); Canvas.Draw(11,11,cur); cur.Handle := LoadCursor(0, IDC_HELP); Canvas.Draw(44,11,cur); cur.Free;end;end./效果图:/附系统光标列表:IDC_ARROW = MakeIntResource(32512);IDC_IBEAM = MakeIntResource(32513);IDC_WAIT = MakeIntResource(32514);IDC_CROSS = MakeIntResource(32515);IDC_UPARROW = MakeIntResource(32516);IDC_SIZE = MakeIntResource(32640);IDC_ICON = MakeIntResource(32641);IDC_SIZENWSE = MakeIntResource(32642);IDC_SIZENESW = MakeIntResource(32643);IDC_SIZEWE = MakeIntResource(32644);IDC_SIZENS = MakeIntResource(32645);IDC_SIZEALL = MakeIntResource(32646);IDC_NO = MakeIntResource(32648);IDC_HAND = MakeIntResource(32649);IDC_APPSTARTING = MakeIntResource(32650);IDC_HELP = MakeIntResource(32651);WinAPI: LoadIcon - 从资源中载入图标 /声明:LoadIcon( hInstance: HINST; EXE 或 DLL 的句柄, 0 表示载入系统资源 lpIconName: PChar 资源标识符): HICON; 返回图标句柄这里有示例 /调用系统图标的例子:unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmprocedure TForm1.Button1Click(Sender: TObject);var ico: TIcon; i,x: Integer;begin ico := TIcon.Create; x := 10; for i := 32512 to 32517 do begin ico.Handle := LoadIcon(0, MakeIntResource(i); Canvas.Draw(x,10,ico); Inc(x,ico.Width+10); end; ico.Free;end;end./效果图:/附系统图标列表:IDI_APPLICATION = MakeIntResource(32512);IDI_HAND = MakeIntResource(32513);IDI_QUESTION = MakeIntResource(32514);IDI_EXCLAMATION = MakeIntResource(32515);IDI_ASTERISK = MakeIntResource(32516);IDI_WINLOGO = MakeIntResource(32517);IDI_WARNING = IDI_EXCLAMATION;IDI_ERROR = IDI_HAND;IDI_INFORMATION = IDI_ASTERISK;WinAPI: AlphaBlend - 图像透明度 AlphaBlend( DC: HDC; 目标设备环境句柄 p2, p3, p4, p5: Integer; 目标位置与宽高 DC6: HDC; 源设备环境句柄 p7, p8, p9, p10: Integer; 源位置与宽高 p11: TBlendFunction 合成方式的数据结构, 见下表): BOOL;/TBlendFunction 结构是 _BLENDFUNCTION 的重命名:_BLENDFUNCTION = packed record BlendOp: BYTE; 本例使用了: AC_SRC_OVER = 0 BlendFlags: BYTE; 必须为 0 SourceConstantAlpha: BYTE; 透明度: 0.255 AlphaFormat: BYTE; 通常为 0，如果源位图为32位真彩色，可为 AC_SRC_ALPHA end;本例效果图:代码文件: unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls, ComCtrls;type TForm1 = class(TForm) TrackBar1: TTrackBar; procedure FormCreate(Sender: TObject); procedure FormPaint(Sender: TObject); procedure TrackBar1Change(Sender: TObject); procedure FormDestroy(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmvar Bit,BitBack: TBitmap; Transparency: Byte = 255; 透明度procedure TForm1.FormCreate(Sender: TObject);begin 设定窗体背景 BitBack := TBitmap.Create; BitBack.LoadFromFile(c:tempBack.bmp); Brush.Bitmap := BitBack; 调入图片 Bit := TBitmap.Create; Bit.LoadFromFile(c:temptest.bmp); 给 TrackBar1 初始化 TrackBar1.Max := 255; TrackBar1.Min := 0; TrackBar1.ShowSelRange := False; TrackBar1.Position := TrackBar1.Max;end;procedure TForm1.FormPaint(Sender: TObject);var Blend: TBlendFunction; 定义 AlphaBlend 要使用的 TBlendFunction 结构begin 给 TBlendFunction 结构赋值 Blend.BlendOp := AC_SRC_OVER; Blend.BlendFlags := 0; Blend.AlphaFormat := 0; Blend.SourceConstantAlpha := Transparency; Windows.AlphaBlend(Canvas.Handle, 因 VCL 有同名属性, 所以指定了是来自 Windows 单元 10, 10, Bit.Width + 10, Bit.Height + 10, Bit.Canvas.Handle, 0, 0, Bit.Width, Bit.Height, Blend );end;procedure TForm1.TrackBar1Change(Sender: TObject);begin Transparency := TrackBar1.Position; Text := IntToStr(Transparency); Self.Repaint; 命令重绘end;procedure TForm1.FormDestroy(Sender: TObject);begin Bit.Free; BitBack.Free;end;end.窗体设计: object Form1: TForm1 Left = 352 Top = 238 Caption = Form1 ClientHeight = 209 ClientWidth = 211 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = Tahoma Font.Style = OldCreateOrder = False Position = poDesigned OnCreate = FormCreate OnDestroy = FormDestroy OnPaint = FormPaint PixelsPerInch = 96 TextHeight = 13 object TrackBar1: TTrackBar Left = 0 Top = 186 Width = 201 Height = 24 TabOrder = 0 OnChange = TrackBar1Change endend用 GDI 操作 EMF 文件1: CreateEnhMetaFile、CloseEnhMetaFile EMF 文件是 Windows 下的增强图元文件, 本例用最简单的代码创建了一个 EMF 文件. CreateEnhMetaFile( DC: HDC; 所参照的 DC, 为 0 表示参照当前的显示设备 FileName: PChar; 文件名, 为 nil 表示创建内存文件 Rect: PRect; 外接矩形(单位是 0.1 毫米), 为 nil 表示使用最小矩形 Desc: PChar 描述性的说明文本, 可为 nil): HDC;unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmprocedure TForm1.Button1Click(Sender: TObject);const Path = C:TempMyMetaFile.emf; CreateEnhMetaFile 创建文件时, 存在则覆盖var MetaFileDC: HDC; EMF 文件 DCbegin MetaFileDC := CreateEnhMetaFile(0, PChar(Path), nil, nil); 建立 Ellipse(MetaFileDC, 10, 10, 100, 60); 绘制 CloseEnhMetaFile(MetaFileDC); 关闭并保存 DeleteObject(MetaFileDC);end;end.增强图元文件的相关函数: CloseEnhMetaFile CopyEnhMetaFile CreateEnhMetaFile DeleteEnhMetaFile EnhMetaFileProc EnumEnhMetaFile GdiComment GetEnhMetaFile GetEnhMetaFileBits GetEnhMetaFileDescription GetEnhMetaFileHeader GetEnhMetaFilePaletteEntries GetWinMetaFileBits PlayEnhMetaFile PlayEnhMetaFileRecord SetEnhMetaFileBits SetWinMetaFileBits 用 GDI 操作 EMF 文件2: PlayEnhMetaFile、DeleteEnhMetaFile 创建 EMF 文件, 并同时绘制在窗体. unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmprocedure TForm1.Button1Click(Sender: TObject);const Path = C:TempMyMetaFile.emf;var MetaFileDC: HDC; EMF 画布句柄 HMetaFile: HENHMETAFILE; EMF 文件句柄begin MetaFileDC := CreateEnhMetaFile(0, PChar(Path), nil, nil); Ellipse(MetaFileDC, 10, 10, 100, 60); HMetaFile := CloseEnhMetaFile(MetaFileDC); 在窗体上按原始大小绘制 EMF PlayEnhMetaFile(Canvas.Handle, HMetaFile, Rect(10,10,100,60); DeleteObject(MetaFileDC); DeleteEnhMetaFile(HMetaFile);end;end.用 GDI 操作 EMF 文件3: GetEnhMetaFile unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmprocedure TForm1.Button1Click(Sender: TObject);const Path = C:TempMyMetaFile.emf; 假定这个文件还在var HMetaFile: HENHMETAFILE; EMF 文件句柄begin HMetaFile := GetEnhMetaFile(PChar(Path); 打开 PlayEnhMetaFile(Canvas.Handle, HMetaFile, Rect(10,10,100,60); 重新绘制 EMF DeleteEnhMetaFile(HMetaFile);end;end.用 GDI 操作 EMF 文件4: 重绘 EMF 本例效果图:代码文件: unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); procedure FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmvar HMetaFile: HENHMETAFILE; f: Boolean; x1,y1: Integer; R: TRect;procedure TForm1.FormCreate(Sender: TObject);const Path = C:TempMyMetaFile.emf;begin HMetaFile := GetEnhMetaFile(PChar(Path);end;procedure TForm1.FormDestroy(Sender: TObject);begin DeleteEnhMetaFile(HMetaFile);end;procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);begin f := True; x1 := X; y1 := Y; R := Rect(x1,y1,X,Y);end;procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);begin if not f then Exit; DrawFocusRect(Canvas.Handle, R); R := Rect(x1,y1,X,Y); DrawFocusRect(Canvas.Handle, R); R := Rect(x1,y1,X,Y);end;procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);begin f := False; PlayEnhMetaFile(Canvas.Handle, HMetaFile, R);end;procedure TForm1.Button1Click(Sender: TObject);begin Refresh;end;end.窗体文件: object Form1: TForm1 Left = 0 Top = 0 Caption = Form1 ClientHeight = 206 ClientWidth = 339 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = Tahoma Font.Style = OldCreateOrder = False Position = poDesktopCenter OnCreate = FormCreate OnDestroy = FormDestroy OnMouseDown = FormMouseDown OnMouseMove = FormMouseMove OnMouseUp = FormMouseUp PixelsPerInch = 96 TextHeight = 13 object Button1: TButton Left = 256 Top = 173 Width = 75 Height = 25 Caption = Button1 TabOrder = 0 OnClick = Button1Click endend用 GDI 操作 EMF 文件5: GetEnhMetaFileDescription - 获取 EMF 文件的说明文本 再用 CreateEnhMetaFile 函数建立 EMF 文件时可以同时写入描述性说明;用 GetEnhMetaFileDescription 函数可以读出 EMF 文件的说明文本.本例给的说明文本非常简单, 不过标准的说明文本的格式应该是: 程序名#0文件标题#0#0 unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmvar HMetaFile: HENHMETAFILE; EMF 文件句柄建立带说明的 EMF 文件procedure TForm1.FormCreate(Sender: TObject);const Path = C:TempMyMeateFile.emf; Description = ABCDE; 当作 EMF 文件的说明var MetaFileDC: HDC;begin 建立并写入说明 MetaFileDC := CreateEnhMetaFile(0, PChar(Path), nil, PChar(Description); 绘图 Rectangle(MetaFileDC, 11, 11, 111, 111); 结束编辑、保存文件, 并返回文件句柄 HMetaFile := CloseEnhMetaFile(MetaFileDC); 删除 DC DeleteObject(MetaFileDC);end;读取 EMF 文件的说明procedure TForm1.Button1Click(Sender: TObject);var DescriptionSize: Integer; 说明段的大小 DescriptionBuf: PChar; 接受说明的内存指针begin 获取大小 DescriptionSize := GetEnhMetaFileDescription(HMetaFile, 0, nil); 分配内存 GetMem(DescriptionBuf, DescriptionSize); 获取说明 GetEnhMetaFileDescription(HMetaFile, DescriptionSize, DescriptionBuf); 显示说明 ShowMessage(DescriptionBuf); ABCDE 释放内存 FreeMem(DescriptionBuf);end;绘制在窗体procedure TForm1.Button2Click(Sender: TObject);begin PlayEnhMetaFile(Canvas.Handle, HMetaFile, Rect(11,11,111,111);end;删除 EMF 文件句柄procedure TForm1.FormDestroy(Sender: TObject);begin DeleteEnhMetaFile(HMetaFile);end;end.用 GDI 操作 EMF 文件6: GetEnhMetaFileHeader - 获取 EMF 的头文件 /增强图元文件的头文件结构 TEnhMetaHeader:tagENHMETAHEADER = packed record iType: DWORD; 记录类型 nSize: DWORD; 结构大小 rclBounds: TRect; 外接矩形(单位是像素) rclFrame: TRect; 图片矩形(单位是 0.1 毫米) dSignature: DWORD; 文件签名 nVersion: DWORD; 文件版本 nBytes: DWORD; 文件尺寸 nRecords: DWORD; 记录数 nHandles: Word; 句柄数 sReserved: Word; 保留 nDescription: DWORD; 说明文本的长度 offDescription: DWORD; 说明文本的偏移量 nPalEntries: DWORD; 调色板的元素数 szlDevice: TSize; 分辨率(像素) szlMillimeters: TSize; 分辨率(毫米) cbPixelFormat: DWORD; offPixelFormat: DWORD; bOpenGL: DWORD; end;本例效果图:unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); end;var Form1: TForm1;implementation$R *.dfmvar HMetaFile: HENHMETAFILE; EMF 文件句柄建立带说明的 EMF 文件procedure TForm1.FormCreate(Sender: TObject);const Path = C:TempMyMeateFile.emf; Description = ABCDE; 当作 EMF 文件的说明var MetaFileDC: HDC;begin 建立并写入说明 MetaFileDC := CreateEnhMetaFile(0, PChar(Path), nil, PChar(Description); 绘图 Rectangle(MetaFileDC, 11, 11, 111, 111); 结束编辑、保存文件, 并返回文件句柄 HMetaFile := CloseEnhMetaFile(MetaFileDC); 删除 DC DeleteObject(MetaFileDC);end;读取 EMF 文件头procedure TForm1.Button1Click(Sender: TObject);const n = #13#10;var MetaHeaderSize: Integer; 文件头大小 MetaHeader: PEnhMetaHeader; 文件头结构的指针 str: string; buf: arrayWord of Char;begin MetaHeaderSize := GetEnhMetaFileHeader(HMetaFile, 0, nil); GetMem(MetaHeader, MetaHeaderSize); GetEnhMetaFileHeader(HMetaFile, MetaHeaderSize, MetaHeader); str := iType: %d + n + nSize: %d + n + rclBounds: %d,%d,%d,%d + n + rclFrame: %d,%d,%d,%d + n + dSignature: %d + n + nVersion: %d + n + nBytes: %d + n + nRecords: %d + n + nHandles: %d + n + /sReserved: %d + n + nDescription: %d + n + offDescription: %d + n + nPalEntries: %d + n + szlDevice: %d,%d + n + szlMillimeters: %d,%d + n + cbPixelFormat: %d + n + offPixelFormat: %d + n + bOpenGL: %d; wvsprintf(buf, PChar(str), PChar(MetaHeader); Show