unit1.pas

ziptv为delphi控件

// ==========================================
// Note:
// 1. For Delphi versions prior v6, search
//    for, and unrem {$IFNDEF DEL6_OR_HIGHER}
//    conditionals.
// 2. Due to the use of MemoryStreams, do not
//    attempt to compress huge amounts of data
//    to the clipboard.  At time of this writing,
//    I am not certain of the memory implications
//    with regard to amount of data to be
//    compressed.
// ==========================================
Unit Unit1;

Interface

Uses
  Windows,
  Messages,
  SysUtils,
  Classes,
  Graphics,
  Controls,
  Forms,
  Dialogs,
  ExtCtrls,
  StdCtrls,
  Buttons,
  ztvStreams;

// include file - to determine Delphi version (for use with conditionals)
{$i ZipTV.inc}  // if using Delphi version conditionals, don't forget to include this!

Type
  TForm1 = Class(TForm)
    Edit1: TEdit;
    Panel1: TPanel;
    Panel2: TPanel;
    Panel3: TPanel;
    OpenDialog1: TOpenDialog;
    Label1: TLabel;
    BitBtn1: TBitBtn;
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    Procedure Button1Click(Sender: TObject);
    Procedure Button2Click(Sender: TObject);
    Procedure BitBtn1Click(Sender: TObject);
  Private
    { Private declarations }
  Public
  	 // TStream[XXX]32 are defined in ztvStreams.pas
//{$ifndef DEL6_OR_HIGHER}	// must include ziptv.inc (see this units header)
//	 Procedure HandleDelphi5Backward(cStream: TStream32);
//{$endif}
  End;


Var
  Form1: TForm1;

Implementation

{$R *.DFM}


Uses
	ClipBrd,
   ztvRegister,
   ztvBase,
   ztvInflate,
   ztvDeflate,
   ztvConsts;


// ==================================================================
// fill Edit1.Text with an existing file to compress
// ==================================================================
Procedure TForm1.BitBtn1Click(Sender: TObject);
Begin
   OpenDialog1.Options := [ofFileMustExist, ofHideReadOnly];
   If Edit1.Text <> '' Then
   Begin
   	OpenDialog1.InitialDir := ExtractFilePath( Edit1.Text );
      OpenDialog1.FileName := ExtractFilename( Edit1.Text )
   End Else
      OpenDialog1.FileName := '*.*';

   OpenDialog1.Title := 'Select file to compress to clipboard';

   If OpenDialog1.Execute() Then
   	Edit1.Text := OpenDialog1.FileName;
End;


// ==================================================================
// Compress to clipboard...
// In this example, we use a TFileStream32 to load data into a stream
// for compression.  You can also use data from a TMemoryStream32.
// ==================================================================
Procedure TForm1.Button1Click(Sender: TObject);
Var
   Crc: Cardinal;
	level: TDeflateType;
   CompressedSize: Int64;
   FileStream: TFileStream32;
Begin
	Memo1.Clear();
	If Not FileExists(Edit1.Text) Then Exit;

   FileStream := TFileStream32.Create(  Edit1.Text, fmOpenRead );
   If (FileStream.Handle < 0) Then
   	Exit;

   Try
   	// ==========================================================
   	// possible values for level:
      //   dtDeflateS	(Stored - no compression)
      //   dtDeflateF	(Fast   - less compression, greater speed)
      //   dtDeflateN	(Normal - normal compression, normal speed)
      //   dtDeflateX	(eXtra  - greater compression, less speed)
   	level := dtDeflateN;
   	// ==========================================================

      // Set the stream position prior to entry of ztvCompress_StreamToClipBoard.
      // In this case, we want to compress the entire file so we set it at byte
      // position 0
      FileStream.Seek(0, soBeginning);

      // ztvCompress_StreamToClipboard is in ztvDeflate.pas
   	Crc :=
      	ztvCompress_StreamToClipboard(
         	FileStream,			// stream to be compressed
            FileStream.Size,  // size of data to be compressed
            CompressedSize,	// returns the CompressedSize
            level);				// compression level

      // CRC_MASK is a constant defined in ztvConsts.pas.  It is the default
      // return value of ztvCompress_StreamToClipboard if comperssion fails.
      //
      // show the result
   	If (Crc <> CRC_MASK) Then
      Begin
      	ShowMessage(
         	'Crc: ' + IntToStr(Crc) + #13 +
         	'Compressed: ' + IntToStr(CompressedSize) + ' bytes'#13 +
         	'Decompressed: ' + IntToStr(FileStream.Size) + ' bytes' )
      End Else
      	ShowMessage('Stream compression to Clipboard failed');

   Finally
   	FileStream.Free();
   End;
End;


// ==================================================================
// Decompress from clipboard...
// ==================================================================
Procedure TForm1.Button2Click(Sender: TObject);
Var
   Crc: Cardinal;
   cStream: TMemoryStream32;
Begin
   // check if compressed data is in the clipboard
   If Clipboard.HasFormat( CF_COMPRESSED_DATA ) Then
   Begin
      cStream := TMemoryStream32.Create();
      Try
      	// ztvDecompress_StreamFromClipboard is in ztvInflate.pas
         Crc :=
         	ztvDecompress_StreamFromClipboard( cStream );

      	// CRC_MASK is a constant defined in ztvConsts.pas.  It is the default
      	// return value of ztvCompress_StreamToClipboard if comperssion fails.
         If Crc <> CRC_MASK {cStream.Size > 0} Then
         Begin

         	// Fill the Memo1 control with decompressed data
//{$ifndef DEL6_OR_HIGHER}	// must include ziptv.inc (see this units header)
//				HandleDelphi5Backward( cStream );
//{$else}
            // fill Memo1 with data
				Memo1.Lines.LoadFromStream( cStream );
//{$endif}

            // show the results
            ShowMessage(
         		'Crc: ' + IntToStr(Crc) + #13 +
               'Decompressed: ' + IntToStr(cStream.Size) + ' bytes');

         End Else
      		ShowMessage('Stream decompression from Clipboard failed');

      Finally
         cStream.Free();
      End;

   End Else
      ShowMessage('Clipboard contains no compressed data');

   Button1.SetFocus();
End;


// ==================================================================
// convert TMemoryStream32 to a Delphi TStream (for compatibility
// with Delphi versions up to (and including) Delphi 5)
// ==================================================================
//{$ifndef DEL6_OR_HIGHER}	// must include ziptv.inc (see this units header)
//Procedure TForm1.HandleDelphi5Backward(cStream: TStream32);
//Var
//   ConvertedStream: TMemoryStream;
//Begin
//   ConvertedStream := TMemoryStream.Create();
//   Try
//      // do the conversion (ztvStreamToTStream is in ztvBase.pas)
//      ztvStreamToTStream(cStream, ConvertedStream, cStream.Size);
//      // fill Memo1 with data
//      Memo1.Lines.LoadFromStream( ConvertedStream );
//   Finally
//      ConvertedStream.Free();
//   End;
//End;
//{$endif}


End.