Reads primitive data types as binary values in a specific encoding.
Namespace:
System.IO
Assembly:
mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
<ComVisibleAttribute(True)> _
Public Class BinaryReader _
Implements IDisposable
Dim instance As BinaryReader
[ComVisibleAttribute(true)]
public class BinaryReader : IDisposable
[ComVisibleAttribute(true)]
public ref class BinaryReader : IDisposable
public class BinaryReader implements IDisposable
For a list of common I/O tasks, see Common I/O Tasks.
The following code example demonstrates how to store and retrieve application settings in a file.
Imports Microsoft.VisualBasic
Imports System
Imports System.IO
Imports System.Security.Permissions
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
' 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
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
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
End Class
using System;
using System.IO;
using System.Security.Permissions;
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();
}
}
// Store and retrieve application settings.
class AppSettings
{
const string fileName = "AppSettings#@@#.dat";
float aspectRatio;
string lookupDir;
int autoSaveTime;
bool 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; }
}
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);
}
}
}
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();
}
System..::.Object
System.IO..::.BinaryReader
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference
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