单元: Clipboards.pas
作者: 姚乔锋 - yaoqiaofeng@sohu.com
日期: 2004.11.27
版本: 1.00
说明: 剪贴板增强类，可支持保存和载入剪贴板，支持多重剪贴板
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unit Clipboard;
interface
uses
SysUtils, windows, messages, Clipbrd, Classes;
type
TBaseClipboard = class(TClipboard)
private
FNextClipHwnd : HWND;
FClipHwnd : HWND;
FViewClipboard: Boolean;
FOnClipboardChanged: TNotifyEvent;
procedure ClipBoardViewerProc(var Msg:TMessage);
procedure SetViewClipboard(const Value: Boolean);
public
procedure AfterConstruction; override;
procedure BeforeDestruction; override;
property ViewClipboard : Boolean read FViewClipboard write SetViewClipboard;
property OnClipboardChanged : TNotifyEvent read fOnClipboardChanged write FOnClipboardChanged;
end;
PClippedData = ^TClippedData;
TClippedData = record
Format : Word;
Buffer : Pointer;
Size : Cardinal;
end;
TManyClipboard = Class(TBaseClipboard)
private
FList : TList;
FIndex : Integer;
function GetCount: Integer;
procedure SetIndex(const Value: Integer);
procedure SetCount(const Value: Integer);
protected
Procedure SaveDatas(List : TList);
Procedure LoadDatas(List : TList);
function GetData(Format : Cardinal; var Buffer : Pointer): Cardinal;
function SetData(Format : Cardinal; Buffer : Pointer; Size: Cardinal): Boolean;
public
procedure AfterConstruction; override;
procedure BeforeDestruction; override;
function Add : Integer; virtual;
procedure Delete(Index : Integer); virtual;
procedure Clear; override;
property Index : Integer Read FIndex Write SetIndex;
property Count : Integer Read GetCount write SetCount;
end;
var
ManyClipboard : TManyClipboard;
implementation
{ TManyClipboard }
function TManyClipboard.Add: Integer;
var
AList : TList;
begin
AList := TList.Create;
Result := FList.Add(AList);
if FIndex < 0 then FIndex := 0;
end;
procedure TManyClipboard.AfterConstruction;
begin
inherited;
FList := TList.Create;
FIndex := -1;
end;
procedure TManyClipboard.BeforeDestruction;
begin
inherited;
Clear;
FList.Free;
end;
procedure TManyClipboard.Clear;
var
I : Integer;
begin
inherited;
for I := 0 To Count - 1 do
Delete(I);
FList.Clear;
end;
procedure TManyClipboard.Delete(Index: Integer);
var
I : Integer;
Blk : PClippedData;
AList : TList;
begin
IF Index in [0..count-1] then
AList := TList(FList[Index])
else Exit;
for I := 0 To AList.Count-1 do
begin
Blk := AList.Items[I];
Dispose(blk);
end;
AList.Free;
FList.Delete(Index);
end;
function TManyClipboard.GetCount: Integer;
begin
Result := FList.Count;
end;
function TManyClipboard.GetData(Format: Cardinal;
var Buffer: Pointer): Cardinal;
var
hmem: Cardinal;
lock: Pointer;
begin
Result := 0;
If OpenClipboard(0) then
begin
hmem := GetClipboardData(Format);
If hmem = 0 then buffer := nil
else begin
Result := GlobalSize(hmem);
buffer := AllocMem(Result);
lock := GlobalLock(hmem);
CopyMemory(buffer, lock, Result);
GlobalUnlock(hmem);
end;
CloseClipboard;
end
else buffer := nil;
end;
procedure TManyClipboard.LoadDatas(List: TList);
var
I : Integer;
Blk : PClippedData;
begin
Clear;
For I := 0 To List.Count-1 Do
begin
Blk := List.Items[I];
SetData(blk.Format, blk.buffer, blk.size);
end;
end;
procedure TManyClipboard.SaveDatas(List: TList);
var
I : Integer;
Blk : PClippedData;
begin
List.Clear;
for I := 0 To FormatCount-1 Do
Begin
New(blk);
Blk.Format := Formats[i];
blk.size := GetData(blk.Format, blk.buffer);
List.Add(Blk);
end;
end;
procedure TManyClipboard.SetCount(const Value: Integer);
var
I : Integer;
begin
for i := 1 to Value do
begin
Add;
end;
end;
function TManyClipboard.SetData(Format: Cardinal; Buffer: Pointer;
Size: Cardinal): Boolean;
var
hmem, sd: Cardinal;
lock: Pointer;
begin
// Allocate memory in the global heap
// Do not free it in this app. It will be freed when the clipboard is cleared
hmem := GlobalAlloc(GMEM_DDESHARE or GMEM_MOVEABLE, size);
lock := GlobalLock(hmem);
CopyMemory(lock, buffer, size);
FreeMem(buffer);
GlobalUnlock(hmem);
If OpenClipboard(0) then
begin
sd := SetClipboardData(format, hmem);
CloseClipboard;
Result := (sd <> 0);
end
else Result := false;
end;
procedure TManyClipboard.SetIndex(const Value: Integer);
begin
IF (Value <> FIndex) and (Value In [0..count - 1]) Then
begin
If FIndex In [0..count - 1] Then
SaveDatas(TList(FList[FIndex]));
FIndex := Value;
If FIndex In [0..count - 1] Then
LoadDatas(TList(FList[FIndex]));
end;
end;
{ TBaseClipboard }
procedure TBaseClipboard.ClipBoardViewerProc(var Msg: TMessage);
begin
with Msg do
case Msg of
WM_DRAWCLIPBOARD :
begin
SendMessage(FNextClipHwnd, Msg, WParam, LParam);
If Assigned(fOnClipboardChanged) then fOnClipboardChanged(Self);
end;
end;
end;
procedure TBaseClipboard.AfterConstruction;
begin
inherited;
FClipHwnd := AllocateHWnd(ClipBoardViewerProc);
end;
procedure TBaseClipboard.SetViewClipboard(const Value: Boolean);
begin
FViewClipboard := Value;
if FViewClipboard then
begin
FNextClipHwnd := SetClipBoardViewer(FClipHwnd);
end
else
begin
ChangeClipboardChain(Handle, FNextClipHwnd);
SendMessage(FNextClipHwnd, WM_CHANGECBCHAIN, FClipHwnd, FNextClipHwnd);
end;
end;
procedure TBaseClipboard.BeforeDestruction;
begin
inherited;
ViewClipboard := False;
DeallocateHWnd(FClipHwnd);
end;
initialization
ManyClipboard := TManyClipboard.Create;
finalization
ManyClipboard.Free;
end.