BinaryReader Class (System.IO)

Imports Microsoft.VisualBasic
Imports System
Imports System.IO
Imports System.Security.Permissions

' Store and retrieve application settings.
Public Class AppSettings

    Const fileName As String = "AppSettings#@@#.dat"
    Dim aspRatio As Single
    Dim lkupDir As String
    Dim saveTime As Integer
    Dim statusBar As Boolean

    Sub New()

        ' Create default application settings.
        aspRatio   = 1.3333
        lkupDir     = "C:\AppDirectory"
        saveTime  = 30
        statusBar = False

        If File.Exists(fileName) Then
            Dim binReader As New BinaryReader( _
                File.Open(fileName, FileMode.Open))
            Try

                ' If the file is not empty,
                ' read the application settings.
                ' First read 4 bytes into a buffer to 
                ' determine if the file is empty.
                Dim testArray As Byte() = {0,0,0,0}
                Dim count As Integer = binReader.Read(testArray, 0, 3)

                If count <> 0 Then

                    ' Reset the position in the stream to zero.
                    binReader.BaseStream.Seek(0, SeekOrigin.Begin)

                    aspRatio   = binReader.ReadSingle()
                    lkupDir     = binReader.ReadString()
                    saveTime  = binReader.ReadInt32()
                    statusBar = binReader.ReadBoolean()
                    Return
                End If

            ' If the end of the stream is reached before reading
            ' the four data values, ignore the error and use the
            ' default settings for the remaining values.
            Catch ex As EndOfStreamException
                Console.WriteLine("{0} caught and ignored. " & _ 
                    "Using default values.", ex.GetType().Name)
            Finally
                binReader.Close()
            End Try
        End If

    End Sub

    ' Create a file and store the application settings.
    Sub Close()
        Dim binWriter As New BinaryWriter( _
            File.Open(fileName, FileMode.Create))
        Try
            binWriter.Write(aspRatio)
            binWriter.Write(lkupDir)
            binWriter.Write(saveTime)
            binWriter.Write(statusBar)
        Finally
            binWriter.Close()
        End Try
    End Sub

    Property AspectRatio As Single
        Get
            Return aspRatio
        End Get
        Set
            aspRatio = Value
        End Set
    End Property

    Property LookupDir As String
        Get
            Return lkupDir
        End Get
        Set
            lkupDir = Value
        End Set
    End Property

    Property AutoSaveTime As Integer
        Get
            Return saveTime
        End Get
        Set
            saveTime = Value
        End Set
    End Property

    Property ShowStatusBar As Boolean
        Get
            Return statusBar
        End Get
        Set
            statusBar = Value
        End Set
    End Property

End Class

Public Class Test
    Shared Sub Main()
        ' Load application settings.
        Dim appSettings As New AppSettings()
        Console.WriteLine("App settings:" & vbcrLf & "Aspect " & _
            "Ratio: {0}, Lookup directory: {1}," & vbcrLf & "Auto " & _
            "save time: {2} minutes, Show status bar: {3}" & vbCrLf, _
            New Object(3){appSettings.AspectRatio.ToString(), _
            appSettings.LookupDir, _
            appSettings.AutoSaveTime.ToString(), _
            appSettings.ShowStatusBar.ToString()})

        ' Change the settings.
        appSettings.AspectRatio   = 1.250
        appSettings.LookupDir     = "C:\Temp"
        appSettings.AutoSaveTime  = 10
        appSettings.ShowStatusBar = True

        ' Save the new settings.
        appSettings.Close()

    End Sub
End Class

using System;
using System.IO;
using System.Security.Permissions;

// Store and retrieve application settings.
class AppSettings
{
    const string fileName = "AppSettings#@@#.dat";
    float  aspectRatio;
    string lookupDir;
    int    autoSaveTime;
    bool   showStatusBar;

    public AppSettings()
    {
        // Create default application settings.
        aspectRatio   = 1.3333F;
        lookupDir     = @"C:\AppDirectory";
        autoSaveTime  = 30;
        showStatusBar = false;

        if(File.Exists(fileName))
        {
            BinaryReader binReader =
                new BinaryReader(File.Open(fileName, FileMode.Open));
            try
            {
                // If the file is not empty,
                // read the application settings.
                // First read 4 bytes into a buffer to
                // determine if the file is empty.
                byte[] testArray = new byte[3];
                int count = binReader.Read(testArray, 0, 3);

                if (count != 0)
                {
                    // Reset the position in the stream to zero.
                    binReader.BaseStream.Seek(0, SeekOrigin.Begin);

                    aspectRatio   = binReader.ReadSingle();
                    lookupDir     = binReader.ReadString();
                    autoSaveTime  = binReader.ReadInt32();
                    showStatusBar = binReader.ReadBoolean();
                }
            }

            // If the end of the stream is reached before reading
            // the four data values, ignore the error and use the
            // default settings for the remaining values.
            catch(EndOfStreamException e)
            {
                Console.WriteLine("{0} caught and ignored. " +
                    "Using default values.", e.GetType().Name);
            }
            finally
            {
                binReader.Close();
            }
        }

    }

    // Create a file and store the application settings.
    public void Close()
    {
        using(BinaryWriter binWriter =
            new BinaryWriter(File.Open(fileName, FileMode.Create)))
        {
            binWriter.Write(aspectRatio);
            binWriter.Write(lookupDir);
            binWriter.Write(autoSaveTime);
            binWriter.Write(showStatusBar);
        }
    }

    public float AspectRatio
    {
        get{ return aspectRatio; }
        set{ aspectRatio = value; }
    }

    public string LookupDir
    {
        get{ return lookupDir; }
        set{ lookupDir = value; }
    }

    public int AutoSaveTime
    {
        get{ return autoSaveTime; }
        set{ autoSaveTime = value; }
    }

    public bool ShowStatusBar
    {
        get{ return showStatusBar; }
        set{ showStatusBar = value; }
    }
}

class Test
{
    static void Main()
    {
        // Load application settings.
        AppSettings appSettings = new AppSettings();
        Console.WriteLine("App settings:\nAspect Ratio: {0}, " +
            "Lookup directory: {1},\nAuto save time: {2} minutes, " +
            "Show status bar: {3}\n",
            new Object[4]{appSettings.AspectRatio.ToString(),
            appSettings.LookupDir, appSettings.AutoSaveTime.ToString(),
            appSettings.ShowStatusBar.ToString()});

        // Change the settings.
        appSettings.AspectRatio   = 1.250F;
        appSettings.LookupDir     = @"C:\Temp";
        appSettings.AutoSaveTime  = 10;
        appSettings.ShowStatusBar = true;

        // Save the new settings.
        appSettings.Close();
    }
}

using namespace System;
using namespace System::IO;
using namespace System::Security::Permissions;

// Store and retrieve application settings.
ref class AppSettings
{
private:
   static String^ fileName =  "AppSettings#@@#.dat";
   float aspectRatio;
   String^ lookupDir;
   int autoSaveTime;
   Boolean showStatusBar;

public:

   property float AspectRatio
   {
      float get()
      {
         return aspectRatio;
      }

      void set( float value )
      {
         aspectRatio = value;
      }

   }

   property String^ LookupDir
   {
      String^ get()
      {
         return lookupDir;
      }

      void set( String^ value )
      {
         lookupDir = value;
      }

   }

   property int AutoSaveTime
   {
      int get()
      {
         return autoSaveTime;
      }

      void set( int value )
      {
         autoSaveTime = value;
      }

   }

   property Boolean ShowStatusBar
   {
      Boolean get()
      {
         return showStatusBar;
      }

      void set( Boolean value )
      {
         showStatusBar = value;
      }

   }
   AppSettings()
   {

      // Create default application settings.
      aspectRatio = 1.3333F;
      lookupDir =  "C:\\AppDirectory";
      autoSaveTime = 30;
      showStatusBar = false;
      if ( File::Exists( fileName ) )
      {

         BinaryReader^ binReader = gcnew BinaryReader( File::Open( fileName, FileMode::Open ) );
         try
         {


            // If the file is not empty,
            // read the application settings.
            // First read 4 bytes into a buffer to
            // determine if the file is empty.
            array<Byte>^testArray = gcnew array<Byte>(3);
            int count = binReader->Read(testArray, 0, 3);
            if ( count != -1 )
            {

               // Reset the position in the stream to zero.
               binReader->BaseStream->Seek(0, SeekOrigin::Begin);

               aspectRatio = binReader->ReadSingle();
               lookupDir = binReader->ReadString();
               autoSaveTime = binReader->ReadInt32();
               showStatusBar = binReader->ReadBoolean();
               return;
            }
         }
         // If the end of the stream is reached before reading
         // the four data values, ignore the error and use the
         // default settings for the remaining values.
         catch ( EndOfStreamException^ e )
         {
            Console::WriteLine( "{0} caught and ignored. "
            "Using default values.", e->GetType()->Name );
         }
         finally
         {
            binReader->Close();
         }


      }
   }


   // Create a file and store the application settings.
   void Close()
   {

      BinaryWriter^ binWriter = gcnew BinaryWriter( File::Open( fileName, FileMode::Create ) );
      try
      {
         binWriter->Write( aspectRatio );
         binWriter->Write( lookupDir );
         binWriter->Write( autoSaveTime );
         binWriter->Write( showStatusBar );
      }
      finally
      {
         binWriter->Close();
      }


   }

};

int main()
{

   // Load application settings.
   AppSettings^ appSettings = gcnew AppSettings;
   array<Object^>^someObject = {appSettings->AspectRatio.ToString(),appSettings->LookupDir,appSettings->AutoSaveTime.ToString(),appSettings->ShowStatusBar.ToString()};
   Console::WriteLine( "App settings:\nAspect Ratio: {0}, "
   "Lookup directory: {1},\nAuto save time: {2} minutes, "
   "Show status bar: {3}\n", someObject );

   // Change the settings.
   appSettings->AspectRatio = 1.250F;
   appSettings->LookupDir =  "C:\\Temp";
   appSettings->AutoSaveTime = 10;
   appSettings->ShowStatusBar = true;

   // Save the new settings.
   appSettings->Close();
}