BinaryWriter 类

以二进制形式将基元类型写入流，并支持用特定的编码写入字符串。

**命名空间:**System.IO
**程序集:**mscorlib（在 mscorlib.dll 中）

声明
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Class BinaryWriter
    Implements IDisposable
用法
Dim instance As BinaryWriter

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
public class BinaryWriter : IDisposable

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
public ref class BinaryWriter : IDisposable

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public class BinaryWriter implements IDisposable

SerializableAttribute 
ComVisibleAttribute(true) 
public class BinaryWriter implements IDisposable

派生类可重写该类的方法，以提供唯一的字符编码。

下表列出了其他典型或相关的 I/O 任务的示例。

下面的代码示例阐释了如何在文件中存储应用程序设置以及如何检索这些设置。

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.
                If binReader.PeekChar() <> -1 Then
                    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.
                if(binReader.PeekChar() != -1)
                {
                    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.
            if ( binReader->PeekChar() != -1 )
            {
               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();
}

import System.*;
import System.IO.*;
import System.Security.Permissions.*;

class Test
{   
    public static void main(String[] args)
    {        
        // 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[]{System.Convert.ToString(appSettings.get_AspectRatio()),
            appSettings.get_LookupDir(),
            System.Convert.ToString(appSettings.get_AutoSaveTime()),
            System.Convert.ToString(appSettings.get_ShowStatusBar())});

        // Change the settings.
        appSettings.set_AspectRatio(1.25F);
        appSettings.set_LookupDir("C:\\Temp");
        appSettings.set_AutoSaveTime ( 10);
        appSettings.set_ShowStatusBar( true);

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

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

    /** @property 
     */
    public float get_AspectRatio()
    {
        return aspectRatio ;
    }//get_AspectRatio

    /** @property 
     */
    public void set_AspectRatio ( float value )
    {
        aspectRatio = value;
    }//set_AspectRatio

    /** @property 
     */
    public String get_LookupDir()
    {
        return lookupDir ;
    }//get_LookupDir

    /** @property 
     */
    public void set_LookupDir ( String value )
    {
        lookupDir = value;
    }//set_LookupDir

    /** @property
     */
    public int get_AutoSaveTime()
    {
        return autoSaveTime ;
    }//get_AutoSaveTime

    /** @property
     */
    public void set_AutoSaveTime ( int value )
    {
        autoSaveTime = value;
    }//set_AutoSaveTime

    /** @property
     */
    public boolean get_ShowStatusBar()
    {
        return showStatusBar ;
    }//get_ShowStatusBar

    /** @property
     */
    public void set_ShowStatusBar ( boolean value )
    {
        showStatusBar = value;
    }//set_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.
                if ( binReader.PeekChar() !=-1  ) {
                    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().get_Name());
            }
            finally {
                binReader.Close();
            }
        }
    } //AppSettings
   
    // Create a file and store the application settings.
    public void Close()
    {
        BinaryWriter binWriter = 
            new BinaryWriter(File.Open(fileName, FileMode.Create));
        try {
            binWriter.Write(aspectRatio);
            binWriter.Write(lookupDir);
            binWriter.Write(autoSaveTime);
            binWriter.Write(showStatusBar);
        }
        finally {
            if ( binWriter != null ) {
                binWriter= null;
            }
        }
    } //Close 
} //AppSettings

System.Object
  System.IO.BinaryWriter

此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

受以下版本支持：2.0、1.1、1.0

受以下版本支持：2.0、1.0

BinaryWriter 成员
System.IO 命名空间
Encoding

文件和流 I/O
如何：从文件读取文本
如何：向文件写入文本
基本的文件 I/O
如何：对新建的数据文件进行读取和写入