我构建了一个小应用程序来截取屏幕截图(Windows / Mac),它可以工作:-)!
对于 Windows 和 Mac 兼容性,我使用流。
API Mac 捕获 --> TStream
API Windows 捕获 --> Vcl.Graphics.TBitmap --> TStream。
之后,我将我的 Windows 或 Mac TStream 加载到 FMX.Types.TBitmap 中(从流中加载)
Windows 单元代码:
unit tools_WIN;
interface
{$IFDEF MSWINDOWS}
uses Classes {$IFDEF MSWINDOWS} , Windows {$ENDIF}, System.SysUtils, FMX.Types, VCL.Forms, VCL.Graphics;
procedure TakeScreenshot(Dest: FMX.Types.TBitmap);
{$ENDIF MSWINDOWS}
implementation
{$IFDEF MSWINDOWS}
procedure WriteWindowsToStream(AStream: TStream);
var
dc: HDC; lpPal : PLOGPALETTE;
bm: TBitMap;
begin
{test width and height}
bm := TBitmap.Create;
bm.Width := Screen.Width;
bm.Height := Screen.Height;
//get the screen dc
dc := GetDc(0);
if (dc = 0) then exit;
//do we have a palette device?
if (GetDeviceCaps(dc, RASTERCAPS) AND RC_PALETTE = RC_PALETTE) then
begin
//allocate memory for a logical palette
GetMem(lpPal, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)));
//zero it out to be neat
FillChar(lpPal^, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)), #0);
//fill in the palette version
lpPal^.palVersion := $300;
//grab the system palette entries
lpPal^.palNumEntries :=GetSystemPaletteEntries(dc,0,256,lpPal^.palPalEntry);
if (lpPal^.PalNumEntries <> 0) then
begin
//create the palette
bm.Palette := CreatePalette(lpPal^);
end;
FreeMem(lpPal, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)));
end;
//copy from the screen to the bitmap
BitBlt(bm.Canvas.Handle,0,0,Screen.Width,Screen.Height,Dc,0,0,SRCCOPY);
bm.SaveToStream(AStream);
FreeAndNil(bm);
//release the screen dc
ReleaseDc(0, dc);
end;
procedure TakeScreenshot(Dest: FMX.Types.TBitmap);
var
Stream: TMemoryStream;
begin
try
Stream := TMemoryStream.Create;
WriteWindowsToStream(Stream);
Stream.Position := 0;
Dest.LoadFromStream(Stream);
finally
Stream.Free;
end;
end;
{$ENDIF MSWINDOWS}
end.
Mac 单元代码:
unit tools_OSX;
interface
{$IFDEF MACOS}
uses
Macapi.CoreFoundation, Macapi.CocoaTypes, Macapi.CoreGraphics, Macapi.ImageIO,
FMX.Types,
system.Classes, system.SysUtils;
procedure TakeScreenshot(Dest: TBitmap);
{$ENDIF MACOS}
implementation
{$IFDEF MACOS}
{$IF NOT DECLARED(CGRectInfinite)}
const
CGRectInfinite: CGRect = (origin: (x: -8.98847e+30; y: -8.98847e+307);
size: (width: 1.79769e+308; height: 1.79769e+308));
{$IFEND}
function PutBytesCallback(Stream: TStream; NewBytes: Pointer;
Count: LongInt): LongInt; cdecl;
begin
Result := Stream.Write(NewBytes^, Count);
end;
procedure ReleaseConsumerCallback(Dummy: Pointer); cdecl;
begin
end;
procedure WriteCGImageToStream(const AImage: CGImageRef; AStream: TStream;
const AType: string = 'public.png'; AOptions: CFDictionaryRef = nil);
var
Callbacks: CGDataConsumerCallbacks;
Consumer: CGDataConsumerRef;
ImageDest: CGImageDestinationRef;
TypeCF: CFStringRef;
begin
Callbacks.putBytes := @PutBytesCallback;
Callbacks.releaseConsumer := ReleaseConsumerCallback;
ImageDest := nil;
TypeCF := nil;
Consumer := CGDataConsumerCreate(AStream, @Callbacks);
if Consumer = nil then RaiseLastOSError;
try
TypeCF := CFStringCreateWithCharactersNoCopy(nil, PChar(AType), Length(AType),
kCFAllocatorNull); //wrap the Delphi string in a CFString shell
ImageDest := CGImageDestinationCreateWithDataConsumer(Consumer, TypeCF, 1, AOptions);
if ImageDest = nil then RaiseLastOSError;
CGImageDestinationAddImage(ImageDest, AImage, nil);
if CGImageDestinationFinalize(ImageDest) = 0 then RaiseLastOSError;
finally
if ImageDest <> nil then CFRelease(ImageDest);
if TypeCF <> nil then CFRelease(TypeCF);
CGDataConsumerRelease(Consumer);
end;
end;
procedure TakeScreenshot(Dest: TBitmap);
var
Screenshot: CGImageRef;
Stream: TMemoryStream;
begin
Stream := nil;
ScreenShot := CGWindowListCreateImage(CGRectInfinite,
kCGWindowListOptionOnScreenOnly, kCGNullWindowID, kCGWindowImageDefault);
if ScreenShot = nil then RaiseLastOSError;
try
Stream := TMemoryStream.Create;
WriteCGImageToStream(ScreenShot, Stream);
Stream.Position := 0;
Dest.LoadFromStream(Stream);
finally
CGImageRelease(ScreenShot);
Stream.Free;
end;
end;
{$ENDIF MACOS}
end.
在您的 mainForm 单元中:
...
{$IFDEF MSWINDOWS}
uses tools_WIN;
{$ELSE}
uses tools_OSX;
{$ENDIF MSWINDOWS}
...
var
imgDest: TImageControl;
...
TakeScreenshot(imgDest.Bitmap);
如果您有其他想法,请与我交谈 :-)