Operating EMF files with GDI [7]: graphic commands in enumenhmetafile and playenhmetafilerecord-enumeration files

Enumenhmetafile (DC: HDC; {target device handle; if the callback function does not require playback, this parameter is 0} EMF: henhmetafile; {metadata file handle} enhmetafunc: tfnenhmfenumproc; {callback function pointer; For the callback function Format, see} data: pointer; {Custom Data Pointer} const rect: trect {size to be output; if Dc = 0, this parameter will be ignored}): bool; // The callback function Format and parameters used by enumenhmetafile. playenhmetafilerecord basically uses these parameters: function enhmetafunc (displaysurface: HDC; {target device handle; if the callback function does not need to be played back, this parameter is 0} var metafiletable: thandletable; {handle table array pointer, the array contains the hgdiobj object (paint brush, paint brush, etc ); element 1 is the file handle} var metafilerecord: tenhmetarecord; {The tenhmetarecord pointer of the Metafile record. The tenhmetarecord structure is shown in the table below} objectcount: integer; {Number of object handles, that is, the number of graphic objects in the metafiletable of the handle table} var data: longint {Custom Data Pointer}): integer; stdcall; // tenhmetarecord structure: tagenhmetarecord = packed record itype: DWORD; {type} nsize: DWORD; {size} dparm: array [0 .. 0] of DWORD; {parameter array} end; // tenhmetarecord. possible values of itype: emr_header = 1; emr_polybezr = 2; emr_polygon = 3; emr_polyline = 4; emr_polybezierto = 5; emr_polylineto = 6; emr_polypolyline = 7; emr_polypolygon = 8; duration = 9; emr_set1_worgex = 10; emr_setviewportextex = 11; duration = 12; duration = 13; emr_eof = 14; emr_setpixelv = 15; emr_setmapperflags = $10; emr_setmapmode = 17; emr_setbkmode = 18; priority = 19; emr_setrop2 = 20; priority = 21; emr_settextalign = 22; priority = 23; emr_settextcolor = 24; emr_setbkcolor = 25; priority = 26; emr_movetoex = 27; emr_setmetargn = 28; cost = 29; cost = 30; cost = 31; cost = 32; emr_savedc = 33; emr_restoredc = 34; emr_setworldtransform = 35; emr_modifyworldtransform = 36; emr_selectobject = 37; emr_createpen = 38; records = 39; emr_deleteobject = 40; emr_anglearc = 41; emr_ellipse = 42; emr_rectangle = 43; records = 44; emr_arc = 45; emr_chord = 46; emr_pie = 47; emr_selectpalette = 48; emr_createpalette = 49; partition = 50; partition = 51; partition = 52; partition = 53; emr_lineto = 54; emr_arcto = 55; emr_polydraw = 56; emr_setarcdirection = 57; lifecycle = 58; emr_beginpath = 59; emr_endpath = 60; emr_closefigure = 61; emr_fillpath = 62; lifecycle = 63; emr_strokepath = $40; emr_flattenpath = 65; emr_widenpath = 66; token = 67; emr_abortpath = 68; emr_gdicomment = 70; emr_fillrgn = 71; emr_framergn = 72; emr_invertrgn = 73; emr_paintrgn = 74; token = 75; emr_bitblt = 76; token = 77; emr_maskblt = 78; emr_plgblt = 79; emr_setdibitstodevice = 80; priority = 81; priority = 82; priority = 83; priority = 84; emr_polybezier16 = 85; emr_polygon16 = 86; emr_polyline16 = 87; priority = 88; emr_polylineto16 = 89; emr_polyline16 = 90; emr_polypolygon16 = 91; emr_polydraw16 = 92; emr_createmonobrush = 93; priority = 94; emr_extcreatepen = 95; priority = 96; Limit = 97; encoding = 98; emr_createcolorspace = 99; emr_setcolorspace = 100; encoding = 101; emr_glsrecord = 102; encoding = 103; emr_pixelformat = 104; emr_drawescape = 105; emr_extescape = 106; emr_startdoc = 107; token = 108; token = 109; emr_namedescape = 110; token = 111; token = 112; token = 113; emr_alphablend = 114; emr_alphadibblend = 115; emr_transparentblt = 116; emr_transparentdib = 117; emr_gradientfill = 118; emr_setlinkedufcm = 119; emr_settextjustification = 120;
 
   
 

In the following example, a primitive file is created in the memory, and a straight line, a rectangle, and two ovans are drawn;

The control displays part and all of the metadata files.

Run:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls, extctrls; Type tform1 = Class (tform) radiogroup1: tradiogroup; procedure formcreate (Sender: tobject); Procedure formdestroy (Sender: tobject); Procedure radiogroup1click (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} var hmetafile: henhmetafile; {EMF file handle} radiogroupitemindex: integer =-1; // callback function of enumenhmetafile: displaysurface: HDC; var metafiletable: thandletable; var metafilerecord: tenhmetarecord; objectcount: integer; var data: longint): integer; stdcall; var itype: integer; begin case radiogroupitemindex of 1: itype: = emr_rectangle; 2: itype: = emr_ellipse; end; If metafilerecord. itype = itype then begin convert (displaysurface, metafiletable, metafilerecord, objectcount); Result: = 1; end; Procedure tform1.formcreate (Sender: tobject); var metafiledc: HDC; begin {file established in memory} metafiledc: = createenhmetafile (0, nil); movetoex (metafiledc, 0, 0, nil); lineto (metafiledc, 100,100 ); {rectangle} rectangle (metafiledc, 10, 10, 30, 30); {elliptic} ellipse (metafiledc, 30, 30, 50, 50); ellipse (metafiledc, 45, 45, 65, 65); hmetafile: = closeenhmetafile (metafiledc); deleteobject (metafiledc); radiogroup1.items. commatext: = 'entire Metafile, where the rectangle, the elliptic '; end; Procedure tform1.radiogroup1click (Sender: tobject); begin repaint; radiogroupitemindex: = radiogroup1.itemindex; if radiogroupitemindex = 0 then playenhmetafile (canvas. handle, hmetafile, clientrect) else enumenhmetafile (canvas. handle, hmetafile, @ myenhmetafunc, nil, clientrect); end; Procedure tform1.formdestroy (Sender: tobject); begin deleteenhmetafile (hmetafile); end.
 
   
 

Form file:

 
Object form1: tform1 left = 0 Top = 0 caption = 'form1' clientheight = 197 clientwidth = 325 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 pixelsperinch = 96 textheight = 13 object radiogroup1: tradiogroup left = 216 Top = 8 width = 101 Height = 113 caption = 'radiogroup1' taborder = 0 onclick = radiogroup1click endend