CompressionMode 列挙体
アセンブリ: System (system.dll 内)

Public Enumeration CompressionMode



CompressionMode 列挙体と GZipStream クラスを使用して、ファイルの圧縮および圧縮解除を実行するコード例を次に示します。
Imports System Imports System.IO Imports System.IO.Compression Public Class GZipTest Shared msg As String Public Shared Function ReadAllBytesFromStream(stream As Stream, buffer() As Byte) As Integer ' Use this method is used to read all bytes from a stream. Dim offset As Integer = 0 Dim totalCount As Integer = 0 While True Dim bytesRead As Integer = stream.Read(buffer, offset, 100) If bytesRead = 0 Then Exit While End If offset += bytesRead totalCount += bytesRead End While Return totalCount End Function 'ReadAllBytesFromStream Public Shared Function CompareData(buf1() As Byte, len1 As Integer, buf2() As Byte, len2 As Integer) As Boolean ' Use this method to compare data from two different buffers. If len1 <> len2 Then msg = "Number of bytes in two buffer are different" & len1 & ":" & len2 MsgBox(msg) Return False End If Dim i As Integer For i = 0 To len1 - 1 If buf1(i) <> buf2(i) Then msg = "byte " & i & " is different " & buf1(i) & "|" & buf2(i) MsgBox(msg) Return False End If Next i msg = "All bytes compare." MsgBox(msg) Return True End Function 'CompareData Public Shared Sub GZipCompressDecompress(filename As String) msg = "Test compression and decompression on file " & filename MsgBox(msg) Dim infile As FileStream Try ' Open the file as a FileStream object. infile = New FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read) Dim buffer(infile.Length - 1) As Byte ' Read the file to ensure it is readable. Dim count As Integer = infile.Read(buffer, 0, buffer.Length) If count <> buffer.Length Then infile.Close() msg = "Test Failed: Unable to read data from file" MsgBox(msg) Return End If infile.Close() Dim ms As New MemoryStream() ' Use the newly created memory stream for the compressed data. Dim compressedzipStream As New GZipStream(ms, CompressionMode.Compress, True) compressedzipStream.Write(buffer, 0, buffer.Length) ' Close the stream. compressedzipStream.Close() msg = "Original size: " & buffer.Length & ", Compressed size: " & ms.Length MsgBox(msg) ' Reset the memory stream position to begin decompression. ms.Position = 0 Dim zipStream As New GZipStream(ms, CompressionMode.Decompress) Dim decompressedBuffer(buffer.Length + 100) As Byte ' Use the ReadAllBytesFromStream to read the stream. Dim totalCount As Integer = GZipTest.ReadAllBytesFromStream(zipStream, decompressedBuffer) msg = "Decompressed " & totalCount & " bytes" MsgBox(msg) If Not GZipTest.CompareData(buffer, buffer.Length, decompressedBuffer, totalCount) Then msg = "Error. The two buffers did not compare." MsgBox(msg) End If zipStream.Close() Catch e As Exception msg = "Error: The file being read contains invalid data." MsgBox(msg) End Try End Sub 'GZipCompressDecompress Public Shared Sub Main(ByVal args() As String) Dim usageText As String = "Usage: GZIPTEST <inputfilename>" 'If no file name is specified, write usage text. If args.Length = 0 Then Console.WriteLine(usageText) Else If File.Exists(args(0)) Then GZipCompressDecompress(args(0)) End If End If End Sub 'Main End Class 'GZipTest
using System; using System.IO; using System.IO.Compression; public class GZipTest { public static int ReadAllBytesFromStream(Stream stream, byte[] buffer) { // Use this method is used to read all bytes from a stream. int offset = 0; int totalCount = 0; while (true) { int bytesRead = stream.Read(buffer, offset, 100); if ( bytesRead == 0) { break; } offset += bytesRead; totalCount += bytesRead; } return totalCount; } public static bool CompareData(byte[] buf1, int len1, byte[] buf2, int len2) { // Use this method to compare data from two different buffers. if (len1 != len2) { Console.WriteLine("Number of bytes in two buffer are different {0}:{1}", len1, len2); return false; } for ( int i= 0; i< len1; i++) { if ( buf1[i] != buf2[i]) { Console.WriteLine("byte {0} is different {1}|{2}", i, buf1[i], buf2[i]); return false; } } Console.WriteLine("All bytes compare."); return true; } public static void GZipCompressDecompress(string filename) { Console.WriteLine("Test compression and decompression on file {0}", filename); FileStream infile; try { // Open the file as a FileStream object. infile = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read); byte[] buffer = new byte[infile.Length]; // Read the file to ensure it is readable. int count = infile.Read(buffer, 0, buffer.Length); if ( count != buffer.Length) { infile.Close(); Console.WriteLine("Test Failed: Unable to read data from file"); return; } infile.Close(); MemoryStream ms = new MemoryStream(); // Use the newly created memory stream for the compressed data. GZipStream compressedzipStream = new GZipStream(ms , CompressionMode.Compress, true); Console.WriteLine("Compression"); compressedzipStream.Write(buffer, 0, buffer.Length); // Close the stream. compressedzipStream.Close(); Console.WriteLine("Original size: {0}, Compressed size: {1}", buffer.Length, ms.Length); // Reset the memory stream position to begin decompression. ms.Position = 0; GZipStream zipStream = new GZipStream(ms, CompressionMode.Decompress); Console.WriteLine("Decompression"); byte[] decompressedBuffer = new byte[buffer.Length + 100]; // Use the ReadAllBytesFromStream to read the stream. int totalCount = GZipTest.ReadAllBytesFromStream(zipStream, decompressedBuffer); Console.WriteLine("Decompressed {0} bytes", totalCount); if( !GZipTest.CompareData(buffer, buffer.Length, decompressedBuffer, totalCount) ) { Console.WriteLine("Error. The two buffers did not compare."); } zipStream.Close(); } // end try catch (InvalidDataException) { Console.WriteLine("Error: The file being read contains invalid data."); } catch (FileNotFoundException) { Console.WriteLine("Error:The file specified was not found."); } catch (ArgumentException) { Console.WriteLine("Error: path is a zero-length string, contains only white space, or contains one or more invalid characters"); } catch (PathTooLongException) { Console.WriteLine("Error: The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters."); } catch (DirectoryNotFoundException) { Console.WriteLine("Error: The specified path is invalid, such as being on an unmapped drive."); } catch (IOException) { Console.WriteLine("Error: An I/O error occurred while opening the file."); } catch (UnauthorizedAccessException) { Console.WriteLine("Error: path specified a file that is read-only, the path is a directory, or caller does not have the required permissions."); } catch (IndexOutOfRangeException) { Console.WriteLine("Error: You must provide parameters for MyGZIP."); } } public static void Main(string[] args) { string usageText = "Usage: MYGZIP <inputfilename>"; //If no file name is specified, write usage text. if (args.Length == 0) { Console.WriteLine(usageText); } else { if (File.Exists(args[0])) GZipCompressDecompress(args[0]); } } }
#using <System.dll> using namespace System; using namespace System::IO; using namespace System::IO::Compression; int ReadAllBytesFromStream( Stream^ stream, array<Byte>^buffer ) { // Use this method is used to read all bytes from a stream. int offset = 0; int totalCount = 0; for ( ; ; ) { int bytesRead = stream->Read( buffer, offset, 100 ); if ( bytesRead == 0 ) { break; } offset += bytesRead; totalCount += bytesRead; } return totalCount; } bool CompareData( array<Byte>^buf1, int len1, array<Byte>^buf2, int len2 ) { // Use this method to compare data from two different buffers. if ( len1 != len2 ) { Console::WriteLine( "Number of bytes in two buffer are different {0}:{1}", len1, len2 ); return false; } for ( int i = 0; i < len1; i++ ) { if ( buf1[ i ] != buf2[ i ] ) { Console::WriteLine( "byte {0} is different {1}|{2}", i, buf1[ i ], buf2[ i ] ); return false; } } Console::WriteLine( "All bytes compare." ); return true; } void GZipCompressDecompress( String^ filename ) { Console::WriteLine( "Test compression and decompression on file {0}", filename ); FileStream^ infile; try { // Open the file as a FileStream object. infile = gcnew FileStream( filename,FileMode::Open,FileAccess::Read,FileShare::Read ); array<Byte>^buffer = gcnew array<Byte>((int)infile->Length); // Read the file to ensure it is readable. int count = infile->Read( buffer, 0, buffer->Length ); if ( count != buffer->Length ) { infile->Close(); Console::WriteLine( "Test Failed: Unable to read data from file" ); return; } infile->Close(); MemoryStream^ ms = gcnew MemoryStream; // Use the newly created memory stream for the compressed data. GZipStream ^ compressedzipStream = gcnew GZipStream( ms,CompressionMode::Compress,true ); Console::WriteLine( "Compression" ); compressedzipStream->Write( buffer, 0, buffer->Length ); // Close the stream. compressedzipStream->Close(); Console::WriteLine( "Original size: {0}, Compressed size: {1}", buffer->Length, ms->Length ); // Reset the memory stream position to begin decompression. ms->Position = 0; GZipStream ^ zipStream = gcnew GZipStream( ms,CompressionMode::Decompress ); Console::WriteLine( "Decompression" ); array<Byte>^decompressedBuffer = gcnew array<Byte>(buffer->Length + 100); // Use the ReadAllBytesFromStream to read the stream. int totalCount = ReadAllBytesFromStream( zipStream, decompressedBuffer ); Console::WriteLine( "Decompressed {0} bytes", totalCount ); if ( !CompareData( buffer, buffer->Length, decompressedBuffer, totalCount ) ) { Console::WriteLine( "Error. The two buffers did not compare." ); } zipStream->Close(); } catch ( InvalidDataException ^ ) { Console::WriteLine( "Error: The file being read contains invalid data." ); } catch ( FileNotFoundException^ ) { Console::WriteLine( "Error:The file specified was not found." ); } catch ( ArgumentException^ ) { Console::WriteLine( "Error: path is a zero-length string, contains only white space, or contains one or more invalid characters" ); } catch ( PathTooLongException^ ) { Console::WriteLine( "Error: The specified path, file name, or both exceed the system-defined maximum length." " For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters." ); } catch ( DirectoryNotFoundException^ ) { Console::WriteLine( "Error: The specified path is invalid, such as being on an unmapped drive." ); } catch ( IOException^ ) { Console::WriteLine( "Error: An I/O error occurred while opening the file." ); } catch ( UnauthorizedAccessException^ ) { Console::WriteLine( "Error: path specified a file that is read-only, the path is a directory, or caller does not have the required permissions." ); } catch ( IndexOutOfRangeException^ ) { Console::WriteLine( "Error: You must provide parameters for MyGZIP." ); } } int main() { array<String^>^args = Environment::GetCommandLineArgs(); String^ usageText = "Usage: MYGZIP <inputfilename>"; //If no file name is specified, write usage text. if ( args->Length == 1 ) { Console::WriteLine( usageText ); } else { if ( File::Exists( args[ 1 ] ) ) GZipCompressDecompress( args[ 1 ] ); } }
import System.*; import System.IO.*; import System.IO.Compression.*; public class GZipTest { public static int ReadAllBytesFromStream(Stream stream, ubyte buffer[]) { // Use this method is used to read all bytes from a stream. int offSet = 0; int totalCount = 0; while (true) { int bytesRead = stream.Read(buffer, offSet, 100); if (bytesRead == 0) { break; } offSet += bytesRead; totalCount += bytesRead; } return totalCount; } //ReadAllBytesFromStream public static boolean CompareData(ubyte buf1[], int len1, ubyte buf2[], int len2) { // Use this method to compare data from two different buffers. if (len1 != len2) { Console.WriteLine("Number of bytes in two buffer are " + "different {0}:{1}", System.Convert.ToString(len1), System.Convert.ToString(len2)); return false; } for (int i = 0; i < len1; i++) { if (!(buf1.get_Item(i).Equals(buf2.get_Item(i)))) { Console.WriteLine("byte {0} is different {1}|{2}", System.Convert.ToString(i), System.Convert.ToString(buf1.get_Item(i)), System.Convert.ToString(buf2.get_Item(i))); return false; } } Console.WriteLine("All bytes compare."); return true; } //CompareData public static void GZipCompressDecompress(String fileName) { Console.WriteLine("Test compression and decompression on file {0}" , fileName); FileStream inFile; try { // Open the file as a FileStream object. inFile = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read); ubyte buffer[] = new ubyte[(ubyte)inFile.get_Length()]; // Read the file to ensure it is readable. int count = inFile.Read(buffer, 0, buffer.length); if (count != buffer.length) { inFile.Close(); Console.WriteLine("Test Failed: Unable to read data from file"); return; } inFile.Close(); MemoryStream ms = new MemoryStream(); // Use the newly created memory stream for the compressed data. GZipStream compressedZipStream = new GZipStream(ms, CompressionMode.Compress, true); Console.WriteLine("Compression"); compressedZipStream.Write(buffer, 0, buffer.length); // Close the stream. compressedZipStream.Close(); Console.WriteLine("Original size: {0}, Compressed size: {1}", System.Convert.ToString(buffer.length), System.Convert.ToString(ms.get_Length())); // Reset the memory stream position to begin decompression. ms.set_Position(0); GZipStream zipStream = new GZipStream(ms, CompressionMode.Decompress); Console.WriteLine("Decompression"); ubyte decompressedBuffer[] = new ubyte[buffer.length + 100]; // Use the ReadAllBytesFromStream to read the stream. int totalCount = GZipTest.ReadAllBytesFromStream(zipStream, decompressedBuffer); Console.WriteLine("Decompressed {0} bytes", System.Convert.ToString(totalCount)); if (!(GZipTest.CompareData(buffer, buffer.length, decompressedBuffer, totalCount))) { Console.WriteLine("Error. The two buffers did not compare."); } zipStream.Close(); } catch (InvalidDataException exp) { Console.WriteLine("Error: The file being read contains" + " invalid data."); } catch (FileNotFoundException exp) { Console.WriteLine("Error:The file specified was not found."); } catch (ArgumentException exp) { Console.WriteLine("Error: path is a zero-length string, contains " + "only white space, or contains one or more invalid characters"); } catch (PathTooLongException exp) { Console.WriteLine("Error: The specified path, file name, or both " + "exceed the system-defined maximum length. For example, on" + " Windows-based platforms, paths must be less than 248 " + "characters, and file names must be less than 260 characters."); } catch (DirectoryNotFoundException exp) { Console.WriteLine("Error: The specified path is invalid, such" + " as being on an unmapped drive."); } catch (IOException exp) { Console.WriteLine("Error: An I/O error occurred while " + "opening the file."); } catch (UnauthorizedAccessException exp) { Console.WriteLine("Error: path specified a file that is read-only ," + " the path is a directory, or caller does not have" + " the required permissions."); } catch (IndexOutOfRangeException exp) { Console.WriteLine("Error: You must provide parameters for MyGZIP."); } } //GZipCompressDecompress public static void main(String[] args) { String usageText = "Usage: MYGZIP <inputfilename>"; //If no file name is specified, write usage text. if (args.length == 0) { Console.WriteLine(usageText); } else { if (File.Exists(args[0])) { GZipCompressDecompress(args[0]); } } } //main } //GZipTest

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
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