Вызов просходит следующим образом....

StringToIcon('This Is Made By Ruslan K. Abu Zant');

N.B>> Не забудьте удалить объект HIcon, после вызова функции...



unit MainForm;

interface

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

type
TForm1 = class(TForm)
   Button1: TButton;
   Image1: TImage;
   Timer1: TTimer;
   procedure Button1Click(Sender: TObject);
   procedure Timer1Timer(Sender: TObject);
private
   function StringToIcon (const st : string) : HIcon;
public
   { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

type
ICONIMAGE = record
   Width, Height, Colors : DWORD; // Ширина, Высота и кол-во цветов
   lpBits : PChar;                // указатель на DIB биты
   dwNumBytes : DWORD;            // Сколько байт?
   lpbi : PBitmapInfoHeader;      // указатель на заголовок
   lpXOR : PChar;                  // указатель на XOR биты изображения
   lpAND : PChar;                  // указатель на AND биты изображения
end;

function CopyColorTable (var lpTarget : BITMAPINFO; const lpSource :
BITMAPINFO) : boolean;
var
dc : HDC;
hPal : HPALETTE;
pe : array [0..255] of PALETTEENTRY;
i : Integer;
begin
result := False;
case (lpTarget.bmiHeader.biBitCount) of
   8 :
     if lpSource.bmiHeader.biBitCount = 8 then
     begin
       Move (lpSource.bmiColors, lpTarget.bmiColors, 256 * sizeof (RGBQUAD));
       result := True
     end
     else
     begin
       dc := GetDC (0);
       if dc <> 0 then
       try
         hPal := CreateHalftonePalette (dc);
         if hPal <> 0 then
         try
           if GetPaletteEntries (hPal, 0, 256, pe) <> 0 then
           begin
             for i := 0 to 255 do
             begin
               lpTarget.bmiColors [i].rgbRed := pe [i].peRed;
               lpTarget.bmiColors [i].rgbGreen := pe [i].peGreen;
               lpTarget.bmiColors [i].rgbBlue := pe [i].peBlue;
               lpTarget.bmiColors [i].rgbReserved := pe [i].peFlags
             end;
             result := True
           end
         finally
           DeleteObject (hPal)
         end
       finally
         ReleaseDC (0, dc)
       end
     end;

   4 :
     if lpSource.bmiHeader.biBitCount = 4 then
     begin
       Move (lpSource.bmiColors, lpTarget.bmiColors, 16 * sizeof (RGBQUAD));
       result := True
     end
     else
     begin
       hPal := GetStockObject (DEFAULT_PALETTE);
       if (hPal <> 0) and (GetPaletteEntries (hPal, 0, 16, pe) <> 0) then
       begin
         for i := 0 to 15 do
         begin
           lpTarget.bmiColors [i].rgbRed := pe [i].peRed;
           lpTarget.bmiColors [i].rgbGreen := pe [i].peGreen;
           lpTarget.bmiColors [i].rgbBlue := pe [i].peBlue;
           lpTarget.bmiColors [i].rgbReserved := pe [i].peFlags
         end;
         result := True
       end
     end;
   1:
     begin
       i := 0;
       lpTarget.bmiColors[i].rgbRed := 0;
       lpTarget.bmiColors[i].rgbGreen := 0;
       lpTarget.bmiColors[i].rgbBlue := 0;
       lpTarget.bmiColors[i].rgbReserved := 0;
       i := 1;
       lpTarget.bmiColors[i].rgbRed := 255;
       lpTarget.bmiColors[i].rgbGreen := 255;
       lpTarget.bmiColors[i].rgbBlue := 255;
       lpTarget.bmiColors[i].rgbReserved := 0;
       result := True
      end;
   else
     result := True
end
end;

function WidthBytes (bits : DWORD) : DWORD;
begin
result := ((bits + 31) shr 5) shl 2
end;

function BytesPerLine (const bmih : BITMAPINFOHEADER) : DWORD;
begin
result := WidthBytes (bmih.biWidth * bmih.biPlanes * bmih.biBitCount)
end;

function DIBNumColors (const lpbi : BitmapInfoHeader) : word;
var
dwClrUsed : DWORD;
begin
dwClrUsed := lpbi.biClrUsed;
if dwClrUsed <> 0 then
   result := Word (dwClrUsed)
else
   case lpbi.biBitCount of
     1 : result := 2;
     4 : result := 16;
     8 : result := 256
     else
       result := 0
   end
end;

function PaletteSize (const lpbi : BitmapInfoHeader) : word;
begin
result := DIBNumColors (lpbi) * sizeof (RGBQUAD)
end;

function FindDIBBits (const lpbi : BitmapInfo) : PChar;
begin
result := @lpbi;
result := result + lpbi.bmiHeader.biSize + PaletteSize (lpbi.bmiHeader)
end;

function ConvertDIBFormat (var lpSrcDIB : BITMAPINFO; nWidth, nHeight, nbpp : DWORD; bStretch : boolean) :
PBitmapInfo;
var
lpbmi : PBITMAPINFO;
lpSourceBits, lpTargetBits : Pointer;
DC, hSourceDC, hTargetDC : HDC;
hSourceBitmap, hTargetBitmap, hOldTargetBitmap, hOldSourceBitmap :
HBITMAP;
dwSourceBitsSize, dwTargetBitsSize, dwTargetHeaderSize : DWORD;
begin
result := Nil;
   // Располагаем и заполняем структуру BITMAPINFO для нового DIB
   // Обеспечиваем достаточно места для 256-цветной таблицы
dwTargetHeaderSize := sizeof ( BITMAPINFO ) + ( 256 * sizeof( RGBQUAD ) );
GetMem (lpbmi, dwTargetHeaderSize);
try
   lpbmi^.bmiHeader.biSize := sizeof (BITMAPINFOHEADER);
   lpbmi^.bmiHeader.biWidth := nWidth;
   lpbmi^.bmiHeader.biHeight := nHeight;
   lpbmi^.bmiHeader.biPlanes := 1;
   lpbmi^.bmiHeader.biBitCount := nbpp;
   lpbmi^.bmiHeader.biCompression := BI_RGB;
   lpbmi^.bmiHeader.biSizeImage := 0;
   lpbmi^.bmiHeader.biXPelsPerMeter := 0;
   lpbmi^.bmiHeader.biYPelsPerMeter := 0;
   lpbmi^.bmiHeader.biClrUsed := 0;
   lpbmi^.bmiHeader.biClrImportant := 0;     // Заполняем в таблице цветов
   if CopyColorTable (lpbmi^, lpSrcDIB) then
   begin
     DC := GetDC (0);
     hTargetBitmap := CreateDIBSection (DC, lpbmi^, DIB_RGB_COLORS,
lpTargetBits, 0, 0 );
     hSourceBitmap := CreateDIBSection (DC, lpSrcDIB, DIB_RGB_COLORS,
lpSourceBits, 0, 0 );

     try
       if (dc <> 0) and (hTargetBitmap <> 0) and (hSourceBitmap <> 0) then
       begin
         hSourceDC := CreateCompatibleDC (DC);
         hTargetDC := CreateCompatibleDC (DC);
         try
           if (hSourceDC <> 0) and (hTargetDC <> 0) then
           begin
             // Flip the bits on the source DIBSection to match the source DIB
             dwSourceBitsSize := DWORD (lpSrcDIB.bmiHeader.biHeight) * BytesPerLine(lpSrcDIB.bmiHeader);
             dwTargetBitsSize := DWORD (lpbmi^.bmiHeader.biHeight) *
BytesPerLine(lpbmi^.bmiHeader);
             Move (FindDIBBits (lpSrcDIB)^, lpSourceBits^, dwSourceBitsSize );

             // Select DIBSections into DCs
             hOldSourceBitmap := SelectObject( hSourceDC, hSourceBitmap );
             hOldTargetBitmap := SelectObject( hTargetDC, hTargetBitmap );

             try
               if (hOldSourceBitmap <> 0) and (hOldTargetBitmap <> 0) then
               begin
           // Устанавливаем таблицу цветов для DIBSections
                 if lpSrcDIB.bmiHeader.biBitCount <= 8 then
                     SetDIBColorTable (hSourceDC, 0, 1 shl lpSrcDIB.bmiHeader.biBitCount, lpSrcDIB.bmiColors);

                 if lpbmi^.bmiHeader.biBitCount <= 8  then
                     SetDIBColorTable (hTargetDC, 0, 1 shl
lpbmi^.bmiHeader.biBitCount, lpbmi^.bmiColors );

                  // If we are asking for a straight copy, do it
                 if (lpSrcDIB.bmiHeader.biWidth = lpbmi^.bmiHeader.biWidth) and (lpSrcDIB.bmiHeader.biHeight = lpbmi^.bmiHeader.biHeight) then
                   BitBlt (hTargetDC, 0, 0, lpbmi^.bmiHeader.biWidth, lpbmi^.bmiHeader.biHeight, hSourceDC, 0, 0, SRCCOPY)
                 else
                   if bStretch then
                   begin
                     SetStretchBltMode (hTargetDC, COLORONCOLOR);
                     StretchBlt (hTargetDC, 0, 0, lpbmi^.bmiHeader.biWidth,
lpbmi^.bmiHeader.biHeight,
hSourceDC, 0, 0, lpSrcDIB.bmiHeader.biWidth, lpSrcDIB.bmiHeader.biHeight,
SRCCOPY )
                   end
                   else
                     BitBlt (hTargetDC, 0, 0, lpbmi^.bmiHeader.biWidth, lpbmi^.bmiHeader.biHeight, hSourceDC, 0, 0, SRCCOPY );

                 GDIFlush;
                 GetMem (result, Integer (dwTargetHeaderSize + dwTargetBitsSize));

                 Move (lpbmi^, result^, dwTargetHeaderSize);
                 Move (lpTargetBits^, FindDIBBits (result^)^, dwTargetBitsSize)
               end
             finally
               if hOldSourceBitmap <> 0 then SelectObject (hSourceDC, hOldSourceBitmap);
               if hOldTargetBitmap <> 0 then SelectObject (hTargetDC, hOldTargetBitmap);
             end
           end
         finally
           if hSourceDC <> 0 then DeleteDC (hSourceDC);
           if hTargetDC <> 0 then DeleteDC (hTargetDC)
         end
       end;
     finally
       if hTargetBitmap <> 0 then DeleteObject (hTargetBitmap);
       if hSourceBitmap <> 0 then DeleteObject (hSourceBitmap);
       if dc <> 0 then ReleaseDC (0, dc)
     end
   end
finally
   FreeMem (lpbmi)
end
end;

function DIBToIconImage (var lpii : ICONIMAGE; var lpDIB : BitmapInfo;
bStretch : boolean) : boolean;
var
lpNewDIB : PBitmapInfo;
begin
result := False;
lpNewDIB := ConvertDIBFormat (lpDIB, lpii.Width, lpii.Height, lpii.Colors,
bStretch );
if Assigned (lpNewDIB) then
try

   lpii.dwNumBytes := sizeof (BITMAPINFOHEADER)                          // Заголовок
                     + PaletteSize (lpNewDIB^.bmiHeader)                      // Палитра
                     + lpii.Height * BytesPerLine (lpNewDIB^.bmiHeader)  // XOR маска
                     + lpii.Height * WIDTHBYTES (lpii.Width);                  // AND маска
      // Если здесь уже картинка, то освобождаем её
   if lpii.lpBits <> Nil then
     FreeMem (lpii.lpBits);

   GetMem (lpii.lpBits,  lpii.dwNumBytes);
   Move (lpNewDib^, lpii.lpBits^, sizeof (BITMAPINFOHEADER) + PaletteSize
(lpNewDIB^.bmiHeader));
     // Выравниваем внутренние указатели/переменные для новой картинки
   lpii.lpbi := PBITMAPINFOHEADER (lpii.lpBits);
   lpii.lpbi^.biHeight := lpii.lpbi^.biHeight * 2;

   lpii.lpXOR := FindDIBBits (PBitmapInfo (lpii.lpbi)^);
   Move (FindDIBBits (lpNewDIB^)^, lpii.lpXOR^, lpii.Height * BytesPerLine
(lpNewDIB^.bmiHeader));

   lpii.lpAND := lpii.lpXOR + lpii.Height * BytesPerLine
(lpNewDIB^.bmiHeader);
   Fillchar (lpii.lpAnd^, lpii.Height * WIDTHBYTES (lpii.Width), $00);

   result := True
finally
   FreeMem (lpNewDIB)
end
end;

function TForm1.StringToIcon (const st : string) : HIcon;
var
memDC : HDC;
bmp : HBITMAP;
oldObj : HGDIOBJ;
rect : TRect;
size : TSize;
infoHeaderSize : DWORD;
imageSize : DWORD;
infoHeader : PBitmapInfo;
icon : IconImage;
oldFont : HFONT;

begin
result := 0;
memDC := CreateCompatibleDC (0);
if memDC <> 0 then
try
   bmp := CreateCompatibleBitmap (Canvas.Handle, 16, 16);
   if bmp <> 0 then
   try
     oldObj := SelectObject (memDC, bmp);
     if oldObj <> 0 then
     try
       rect.Left := 0;
       rect.top := 0;
       rect.Right := 16;
       rect.Bottom := 16;
       SetTextColor (memDC, RGB (255, 0, 0));
       SetBkColor (memDC, RGB (128, 128, 128));
       oldFont := SelectObject (memDC, font.Handle);
       GetTextExtentPoint32 (memDC, PChar (st), Length (st), size);
       ExtTextOut (memDC, (rect.Right - size.cx) div 2, (rect.Bottom - size.cy) div 2, ETO_OPAQUE, @rect, PChar (st), Length (st), Nil);
       SelectObject (memDC, oldFont);
       GDIFlush;

       GetDibSizes (bmp, infoHeaderSize, imageSize);
       GetMem (infoHeader, infoHeaderSize + ImageSize);
       try
         GetDib (bmp, SystemPalette16, infoHeader^, PChar (DWORD (infoHeader) + infoHeaderSize)^);

         icon.Colors := 4;
         icon.Width := 32;
         icon.Height := 32;
         icon.lpBits := Nil;
         if DibToIconImage (icon, infoHeader^, True) then
         try
           result := CreateIconFromResource (PByte (icon.lpBits), icon.dwNumBytes, True, $00030000);
         Finally
           FreeMem (icon.lpBits)
         end
       finally
         FreeMem (infoHeader)
       end

     finally
       SelectObject (memDC, oldOBJ)
     end
   finally
     DeleteObject (bmp)
   end
finally
   DeleteDC (memDC)
end
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Application.Icon.Handle := StringToIcon ('0');
Timer1.Enabled := True;
Button1.Enabled := False;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
const i : Integer = 0;
begin
Inc (i);
if i = 100 then i := 1;
Application.Icon.Handle := StringToIcon (IntToStr (i));

end;

end.