可以利用COM+来传输文件吗？如果可以，该怎样实现呢？

Question

如题！

Answer 1

楼主意思是要自己做一个com组件，用来传输文件吗？顺便提一下，你的信誉分真低

Answer 2

可以
偶这就有将文件打包成Variant，然后进行传输，接收后再保存为文件的代码。
=======================================================
unit FilePacket;{$WARN SYMBOL_PLATFORM OFF}interfaceuses
  ComObj, ActiveX, FilePacket_TLB, StdVcl;type
  TFilePacket = class(TAutoObject, IFilePacket)
  protected
    procedure ReadFilePacket(const FileName: WideString;
      var Packet: OleVariant); safecall;
    procedure ReadFilePacket2(const FileName: WideString;
      var Packet: OleVariant); safecall;
    procedure ReadFile(const FileName: WideString;
      var Packet: OleVariant); safecall;
    function WriteFileStream(var Stream: OleVariant;
      const FileName: WideString): SYSINT; safecall;
    function WriteFile(var Stream: OleVariant;
      const FileName: WideString): SYSINT; safecall;
    procedure ReadFile2(const FileName: WideString;
      var Packet: OleVariant); safecall;
    procedure PackStream(var Stream: OleVariant); safecall;
    procedure UnPackStream(var Stream: OleVariant); safecall;
    { Protected declarations }
  end;implementationuses ComServ,Zlib,Classes,SysUtils,Variants,windows;procedure TFilePacket.ReadFilePacket(const FileName: WideString; var Packet: OleVariant);
var
  ZStream: TCompressionStream;
  TempStream:TFileStream;
  InStream:TMemoryStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  pj:Pointer;
  bSize:int64;
begin
  InStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  TempStream:=TFileStream.Create(String(FileName),fmOpenRead);
  try
     ZStream:=TCompressionStream.Create(cldefault, InStream);
     try
        ZStream.CopyFrom(TempStream,0);
     finally
        ZStream.Free;
     end;
     Param:=VarArrayCreate([0,InStream.Size-1+sizeof(bSize)],varByte);
     p:=VarArrayLock(Param);
     try
        pj:=Addr(bSize);
        bSize:=TempStream.Size;
        BStream.Write(pj^,sizeof(bSize));
        BStream.Position:=sizeof(bSize);
        InStream.Position:=0;
        BStream.CopyFrom(InStream,InStream.Size);
        bstream.Position:=0;        BStream.Read(p^,BStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     InStream.Free;
     BStream.Free;
     TempStream.Free;
  end;
  if not DeleteFile(PChar(AnsiString(FileName))) then
  begin
     Sleep(1000);
     DeleteFile(PChar(AnsiString(FileName)));
  end;
  Packet:=Param;
end;
procedure TFilePacket.ReadFilePacket2(const FileName: WideString; var Packet: OleVariant);
var
  ZStream: TCompressionStream;
  TempStream:TFileStream;
  InStream:TMemoryStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  pj:Pointer;
  bSize:int64;
begin
  InStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  TempStream:=TFileStream.Create(String(FileName),fmOpenRead);
  try
     ZStream:=TCompressionStream.Create(cldefault, InStream);
     try
        ZStream.CopyFrom(TempStream,0);
     finally
        ZStream.Free;
     end;
     Param:=VarArrayCreate([0,InStream.Size-1+sizeof(bSize)],varByte);
     p:=VarArrayLock(Param);
     try
        pj:=Addr(bSize);
        bSize:=TempStream.Size;
        BStream.Write(pj^,sizeof(bSize));
        BStream.Position:=sizeof(bSize);
        InStream.Position:=0;
        BStream.CopyFrom(InStream,InStream.Size);
        bstream.Position:=0;        BStream.Read(p^,BStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     InStream.Free;
     BStream.Free;
     TempStream.Free;
  end;
  Packet:=Param;
end;
procedure TFilePacket.ReadFile2(const FileName: WideString; var Packet: OleVariant);
var
  TempStream:TFileStream;
  Param:OleVariant;
  p:Pointer;
begin
  TempStream:=TFileStream.Create(String(FileName),fmOpenRead);
  try
     Param:=VarArrayCreate([0,TempStream.Size-1],varByte);
     p:=VarArrayLock(Param);
     try
        TempStream.Position:=0;
        TempStream.Read(p^,TempStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     TempStream.Free;
  end;
  if not DeleteFile(PChar(AnsiString(FileName))) then
  begin
     Sleep(1000);
     DeleteFile(PChar(AnsiString(FileName)));
  end;
  Packet:=Param;
end;
procedure TFilePacket.ReadFile(const FileName: WideString; var Packet: OleVariant);
var
  TempStream:TFileStream;
  Param:OleVariant;
  p:Pointer;
begin
  TempStream:=TFileStream.Create(String(FileName),fmOpenRead);
  try
     Param:=VarArrayCreate([0,TempStream.Size-1],varByte);
     p:=VarArrayLock(Param);
     try
        TempStream.Position:=0;
        TempStream.Read(p^,TempStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     TempStream.Free;
  end;
  Packet:=Param;
end;

Answer 3

function TFilePacket.WriteFileStream(var Stream: OleVariant;
  const FileName: WideString): SYSINT;
var
  TempStream:TMemoryStream;
  OutStream:TFileStream;
  ZStream: TDecompressionStream;
  BStream:TMemoryStream;
  p:Pointer;
  bSize:int64;
  pj:Pointer;
begin
  Result:=-1;
  TempStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  p:=VarArrayLock(Stream);
  try
     TempStream.Write(p^,VarArrayHighBound(Stream,1)+1);
     OutStream:=TFileStream.Create(String(FileName),fmCreate);
     pj:=Addr(bSize);
     TempStream.Position:=0;
     TempStream.Read(pj^,sizeof(bSize));
     TempStream.Position:=sizeof(bSize);
     if TempStream.Size >0 then BStream.CopyFrom(TempStream,TempStream.Size-sizeof(bSize));
     BStream.Position:=0;
     ZStream:=TDecompressionStream.Create(BStream);
     zstream.Position:=0;
     try
        if bSize>0 then OutStream.CopyFrom(ZStream,bSize);
     finally
        ZStream.Free;
        OutStream.Free;
     end;
  finally
     VarArrayUnlock(Stream);
     BStream.Free;
     TempStream.Free;
  end;
  Result:=0;
end;
function TFilePacket.WriteFile(var Stream: OleVariant;
  const FileName: WideString): SYSINT;
var
  OutStream:TFileStream;
  p:Pointer;
begin
  Result:=-1;
  p:=VarArrayLock(Stream);
  OutStream:=TFileStream.Create(String(FileName),fmCreate);
  try
     OutStream.Write(p^,VarArrayHighBound(Stream,1)+1);
  finally
     VarArrayUnlock(Stream);
     OutStream.Free;
  end;
  Result:=0;
end;
procedure TFilePacket.PackStream(var Stream: OleVariant);
var
  ZStream: TCompressionStream;
  InStream:TMemoryStream;
  TempStream:TMemoryStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  pi:Pointer;
  pj:Pointer;
  bSize:int64;
begin
  InStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  TempStream:=TMemoryStream.Create;
  pi:=VarArrayLock(Stream);
  try
     TempStream.Write(pi^,VarArrayHighBound(Stream,1)+1);
     ZStream:=TCompressionStream.Create(cldefault, InStream);
     try
        ZStream.CopyFrom(TempStream,0);
     finally
        ZStream.Free;
     end;
     Param:=VarArrayCreate([0,InStream.Size-1+sizeof(bSize)],varByte);
     p:=VarArrayLock(Param);
     try
        pj:=Addr(bSize);
        bSize:=TempStream.Size;
        BStream.Write(pj^,sizeof(bSize));
        BStream.Position:=sizeof(bSize);
        InStream.Position:=0;
        BStream.CopyFrom(InStream,InStream.Size);
        bstream.Position:=0;
        BStream.Read(p^,BStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     VarArrayUnlock(Stream);
     InStream.Free;
     TempStream.Free;
     BStream.Free;
  end;
  Stream:=Param;
end;
procedure TFilePacket.UnPackStream(var Stream: OleVariant);
var
  TempStream:TMemoryStream;
  OutStream:TMemoryStream;
  ZStream: TDecompressionStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  po:Pointer;
  bSize:int64;
  pj:Pointer;
begin
  TempStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  OutStream:=TMemoryStream.Create;
  p:=VarArrayLock(Stream);
  try
     TempStream.Write(p^,VarArrayHighBound(Stream,1)+1);
     pj:=Addr(bSize);
     TempStream.Position:=0;
     TempStream.Read(pj^,sizeof(bSize));
     TempStream.Position:=sizeof(bSize);
     if TempStream.Size>0 then BStream.CopyFrom(TempStream,TempStream.Size-sizeof(bSize));
     BStream.Position:=0;
     ZStream:=TDecompressionStream.Create(BStream);
     zstream.Position:=0;
     try
        OutStream.CopyFrom(ZStream,bSize);
        Param:=VarArrayCreate([0,OutStream.Size-1],varByte);
        po:=VarArrayLock(Param);
        try
           OutStream.Position:=0;
           OutStream.Read(po^,OutStream.Size);
        finally
           VarArrayUnlock(Param);
        end;
     finally
        ZStream.Free;
     end;
  finally
     VarArrayUnlock(Stream);
     BStream.Free;
     OutStream.Free;
     TempStream.Free;
  end;
  Stream:=Param;
end;
initialization
  TAutoObjectFactory.Create(ComServer, TFilePacket, Class_FilePacket,
    ciMultiInstance, tmApartment);
end.

Answer 4

我试过，但这种方式比Socket传文件慢多了。
COM服务器:
function TComClass.GetFile(const FileName: WideString; StartPos,
  Length: Integer; var vData: OleVariant): OleVariant;
var aFileStream:TFileStream;
    aLength,aMore:LongInt;
    aStrPath,aStrFileName:String;
    Buf:PChar;
    I:Integer;
    aChr:Char;
begin
  vData:=UnAssigned;
  Result:=0;
  aStrPath:=ExtractFilePath(Application.ExeName);
  aStrFileName:=aStrPath+FileName;
  if not FileExists(aStrFileName) then Exit;
  aFileStream:=TFileStream.Create(FileName,fmOpenRead,fmShareDenyNone);
 try
  aLength:=aFileStream.Size;
  if StartPos>=aLength then
  begin
    Exit;
  end;
  aLength:=aLength-StartPos;
  if aLength>Length then
    aLength:=Length;
  aMore:=aFileStream.Size-StartPos-aLength;
    Result:=aMore;
  if aLength<=0 then Exit;
    GetMem(Buf,aLength);
  try
    aFileStream.Position:=StartPos;
    aFileStream.ReadBuffer(Buf^,aLength);
    vData:=VarArrayCreate([0,aLength],varVariant);
    for I:=0 to aLength-1 do
    begin
      aChr:=Buf[I];
      vData[I]:=aChr;
    end;
  finally
    FreeMem(Buf);
  end;
 finally
  aFileStream.Free;
 end;
end;客户端:
procedure GetServerFile(aFileName:String);
var aFileStream:TFileStream;
    aFileLength,aStartPos,aBufLength,aMoreBytes,aDataLength:LongInt;
    aPath,aFullFileName,aStrX:String;
    Buf:PChar;
    I:Integer;
    vData,vRslt: OleVariant;
    aChr:Char;
begin
  aPath:=ExtractFilePath(Application.ExeName);
  aFullFileName:=aPath+aFileName;
  aStartPos:=0;
  aBufLength:=0;
  vRslt:=ComClass.GetFile(aFileName,aStartPos,aBufLength,vData);
  aFileLength:=0;
  if not VarIsNull(vRslt) then
  aFileLength:=vRslt;
  if aFileLength<=0 then Exit;
    aFileStream:=TFileStream.Create(aFullFileName,fmCreate,fmShareDenyRead);
    aBufLength:=1024;
    GetMem(Buf,aBufLength);
  try    aMoreBytes:=aFileLength;
    aStartPos:=0;
    while aMoreBytes>0 do
    begin
      vRslt:=ComClass.GetFile(aFileName,aStartPos,aBufLength,vData);
      aMoreBytes:=0;
      if not VarIsNull(vRslt) then
        aMoreBytes:=vRslt;
      aDataLength:=0;
      if VarIsArray(vData) then
      begin
        aDataLength:=VarArrayHighBound(vData,1);
        for I:=0 to aDataLength-1 do
        begin
          aStrX:=vData[I];
          aChr:=aStrX[1];
          Buf[I]:=aChr;
        end;
        aFileStream.WriteBuffer(Buf^,aDataLength);
      end;
      aStartPos:=aStartPos+aDataLength;
    end;  finally
    FreeMem(Buf);
    aFileStream.Free;
  end;end;
客户端每次收1024字节，合成整个文件。