BinaryReader.Read BinaryReader.Read BinaryReader.Read BinaryReader.Read Method

Definition

Liest Bytes aus dem zugrunde liegenden Datenstrom und erhöht die aktuelle Position des Datenstroms.Reads bytes from the underlying stream and advances the current position of the stream.

Überlädt

Read() Read() Read() Read()

Liest Zeichen aus dem zugrunde liegenden Stream und erhöht die aktuelle Position im Stream in Abhängigkeit von der verwendeten Encoding und dem aus dem Stream gelesenen Zeichen.Reads characters from the underlying stream and advances the current position of the stream in accordance with the Encoding used and the specific character being read from the stream.

Read(Span<Byte>) Read(Span<Byte>) Read(Span<Byte>) Read(Span<Byte>)
Read(Span<Char>) Read(Span<Char>) Read(Span<Char>) Read(Span<Char>)
Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32)

Liest die angegebene Anzahl von Bytes beginnend bei einem angegebenen Punkt im Bytearray aus dem Datenstrom.Reads the specified number of bytes from the stream, starting from a specified point in the byte array.

Read(Char[], Int32, Int32) Read(Char[], Int32, Int32) Read(Char[], Int32, Int32) Read(Char[], Int32, Int32)

Liest die angegebene Anzahl von Zeichen beginnend bei einem angegebenen Punkt im Zeichenarray aus dem Datenstrom.Reads the specified number of characters from the stream, starting from a specified point in the character array.

Read() Read() Read() Read()

Liest Zeichen aus dem zugrunde liegenden Stream und erhöht die aktuelle Position im Stream in Abhängigkeit von der verwendeten Encoding und dem aus dem Stream gelesenen Zeichen.Reads characters from the underlying stream and advances the current position of the stream in accordance with the Encoding used and the specific character being read from the stream.

public:
 virtual int Read();
public virtual int Read ();
abstract member Read : unit -> int
override this.Read : unit -> int
Public Overridable Function Read () As Integer

Gibt zurück

Das nächste Zeichen aus dem Eingabestream bzw. -1, wenn derzeit keine Zeichen verfügbar sind.The next character from the input stream, or -1 if no characters are currently available.

Ausnahmen

Ein E/A-Fehler tritt auf.An I/O error occurs.

Beispiele

Im folgenden Beispiel wird gezeigt, wie Sie Daten mit dem Arbeitsspeicher als Sicherungs Speicher lesen und schreiben.The following example shows how to read and write data using memory as a backing store. In diesem Beispiel wird eine Liste der ungültigen Datei Pfad Zeichen in der Konsole angezeigt.This example displays a list of invalid file path characters to the console. Obwohl der Code versucht, eine Liste aller ungültigen Datei Pfad Zeichen anzuzeigen, sind nicht alle Zeichen innerhalb des anzeigbaren Zeichensatzes enthalten.Although the code tries to display a list of all invalid file path characters, not all of the characters are within the displayable set of characters. Da die Liste der ungültigen Zeichen basierend auf dem System variieren kann, kann die Ausgabe für diesen Code ebenfalls variieren.Because the list of invalid characters can vary based on the system, output for this code may also vary.

using namespace System;
using namespace System::IO;
int main()
{
   int i;
   array<Char>^invalidPathChars = Path::InvalidPathChars;
   MemoryStream^ memStream = gcnew MemoryStream;
   BinaryWriter^ binWriter = gcnew BinaryWriter( memStream );
   
   // Write to memory.
   binWriter->Write( "Invalid file path characters are: " );
   for ( i = 0; i < invalidPathChars->Length; i++ )
   {
      binWriter->Write( invalidPathChars[ i ] );

   }
   
   // Create the reader using the same MemoryStream 
   // as used with the writer.
   BinaryReader^ binReader = gcnew BinaryReader( memStream );
   
   // Set Position to the beginning of the stream.
   binReader->BaseStream->Position = 0;
   
   // Read the data from memory and write it to the console.
   Console::Write( binReader->ReadString() );
   array<Char>^memoryData = gcnew array<Char>(memStream->Length - memStream->Position);
   for ( i = 0; i < memoryData->Length; i++ )
   {
      memoryData[ i ] = Convert::ToChar( binReader->Read() );

   }
   Console::WriteLine( memoryData );
}

using System;
using System.IO;

class BinaryRW
{
    static void Main()
    {
        int i = 0;
        char[] invalidPathChars = Path.InvalidPathChars;
        MemoryStream memStream = new MemoryStream();
        BinaryWriter binWriter = new BinaryWriter(memStream);

        // Write to memory.
        binWriter.Write("Invalid file path characters are: ");
        for(i = 0; i < invalidPathChars.Length; i++)
        {
            binWriter.Write(invalidPathChars[i]);
        }

        // Create the reader using the same MemoryStream 
        // as used with the writer.
        BinaryReader binReader = new BinaryReader(memStream);

        // Set Position to the beginning of the stream.
        memStream.Position = 0;

        // Read the data from memory and write it to the console.
        Console.Write(binReader.ReadString());
        char[] memoryData = 
            new char[memStream.Length - memStream.Position];
        for(i = 0; i < memoryData.Length; i++)
        {
            memoryData[i] = Convert.ToChar(binReader.Read());
        }
        Console.WriteLine(memoryData);
    }
}
Imports System.IO

Public Class BinaryRW

    Shared Sub Main()
    
        Dim i As Integer = 0
        Dim invalidPathChars() As Char = Path.InvalidPathChars
        Dim memStream As new MemoryStream()
        Dim binWriter As New BinaryWriter(memStream)

        ' Write to memory.
        binWriter.Write("Invalid file path characters are: ")
        For i = 0 To invalidPathChars.Length - 1
            binWriter.Write(invalidPathChars(i))
        Next i

        ' Create the reader using the same MemoryStream 
        ' as used with the writer.
        Dim binReader As New BinaryReader(memStream)

        ' Set Position to the beginning of the stream.
        memStream.Position = 0

        ' Read the data from memory and write it to the console.
        Console.Write(binReader.ReadString())
        Dim memoryData( _
            CInt(memStream.Length - memStream.Position) - 1) As Char
        For i = 0 To memoryData.Length - 1
            memoryData(i) = Convert.ToChar(binReader.Read())
        Next i
        Console.WriteLine(memoryData)
    
	End Sub
End Class

Hinweise

BinaryReaderstellt die Dateiposition nach einem nicht erfolgreichen Lesevorgang nicht wieder her.BinaryReader does not restore the file position after an unsuccessful read.

Eine Liste der allgemeinen e/a-Aufgaben finden Sie unter Allgemeine e/a-Aufgaben.For a list of common I/O tasks, see Common I/O Tasks.

Siehe auch

Read(Span<Byte>) Read(Span<Byte>) Read(Span<Byte>) Read(Span<Byte>)

public:
 virtual int Read(Span<System::Byte> buffer);
public virtual int Read (Span<byte> buffer);
abstract member Read : Span<byte> -> int
override this.Read : Span<byte> -> int
Public Overridable Function Read (buffer As Span(Of Byte)) As Integer

Parameter

buffer
Span<Byte>

Gibt zurück

Read(Span<Char>) Read(Span<Char>) Read(Span<Char>) Read(Span<Char>)

public:
 virtual int Read(Span<char> buffer);
public virtual int Read (Span<char> buffer);
abstract member Read : Span<char> -> int
override this.Read : Span<char> -> int
Public Overridable Function Read (buffer As Span(Of Char)) As Integer

Parameter

buffer
Span<Char>

Gibt zurück

Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32) Read(Byte[], Int32, Int32)

Liest die angegebene Anzahl von Bytes beginnend bei einem angegebenen Punkt im Bytearray aus dem Datenstrom.Reads the specified number of bytes from the stream, starting from a specified point in the byte array.

public:
 virtual int Read(cli::array <System::Byte> ^ buffer, int index, int count);
public virtual int Read (byte[] buffer, int index, int count);
abstract member Read : byte[] * int * int -> int
override this.Read : byte[] * int * int -> int
Public Overridable Function Read (buffer As Byte(), index As Integer, count As Integer) As Integer

Parameter

buffer
Byte[]

Der Puffer, in den Daten gelesen werden sollen.The buffer to read data into.

index
Int32 Int32 Int32 Int32

Der Anfangspunkt für das Lesen in den Puffer.The starting point in the buffer at which to begin reading into the buffer.

count
Int32 Int32 Int32 Int32

Die Anzahl der zu lesenden Bytes.The number of bytes to read.

Gibt zurück

Die Anzahl von Bytes, die in buffer gelesen wurden.The number of bytes read into buffer. Diese kann kleiner sein als die Anzahl der angeforderten Bytes, wenn gegenwärtig keine entsprechende Anzahl von Bytes verfügbar ist, oder null, wenn das Ende des Streams erreicht ist.This might be less than the number of bytes requested if that many bytes are not available, or it might be zero if the end of the stream is reached.

Ausnahmen

Die Pufferlänge minus index ist kleiner als count.The buffer length minus index is less than count.

- oder --or- Die Anzahl der zu lesenden decodierten Zeichen ist größer als count.The number of decoded characters to read is greater than count. Dies kann geschehen, wenn ein Unicode-Decoder Fallbackzeichen oder ein Ersatzzeichenpaar zurückgibt.This can happen if a Unicode decoder returns fallback characters or a surrogate pair.

index oder count ist ein negativer Wert.index or count is negative.

Ein E/A-Fehler tritt auf.An I/O error occurs.

Beispiele

Im folgenden Beispiel wird gezeigt, wie Binärdaten mithilfe von Arbeitsspeicher als Sicherungs Speicher geschrieben werden.The following example shows how to write binary data by using memory as a backing store. Es wird eine Meldung an die Konsole angezeigt, die angibt, ob die Daten ordnungsgemäß geschrieben wurden.It displays a message to the console that indicates whether the data was written correctly.

using System;
using System.IO;

namespace BinaryRW
{
    class Program
    {
        static void Main(string[] args)
        {
            const int arrayLength = 1000;
            byte[] dataArray = new byte[arrayLength];
            byte[] verifyArray = new byte[arrayLength];

            new Random().NextBytes(dataArray);

            using (BinaryWriter binWriter = new BinaryWriter(new MemoryStream()))
            {
                Console.WriteLine("Writing the data.");
                binWriter.Write(dataArray, 0, arrayLength);

                using (BinaryReader binReader = new BinaryReader(binWriter.BaseStream))
                {
                    binReader.BaseStream.Position = 0;
                    
                    if (binReader.Read(verifyArray, 0, arrayLength) != arrayLength)
                    {
                        Console.WriteLine("Error writing the data.");
                        return;
                    }
                }
            }

            for (int i = 0; i < arrayLength; i++)
            {
                if (verifyArray[i] != dataArray[i])
                {
                    Console.WriteLine("Error writing the data.");
                    return;
                }
            }

            Console.WriteLine("The data was written and verified.");
        }
    }
}
Imports System.IO

Module Module1

    Sub Main()
        Const upperBound As Integer = 1000
        Dim dataArray(upperBound) As Byte
        Dim verifyArray(upperBound) As Byte

        Dim randomGenerator As New Random
        randomGenerator.NextBytes(dataArray)

        Using binWriter As New BinaryWriter(New MemoryStream())
            Console.WriteLine("Writing the data.")
            binWriter.Write(dataArray, 0, dataArray.Length)

            Using binReader As New BinaryReader(binWriter.BaseStream)
                binReader.BaseStream.Position = 0

                If binReader.Read(verifyArray, 0, dataArray.Length) <> dataArray.Length Then
                    Console.WriteLine("Error writing the data.")
                    Return
                End If
            End Using
        End Using

        For i As Integer = 0 To upperBound
            If verifyArray(i) <> dataArray(i) Then
                Console.WriteLine("Error writing the data.")
                Return
            End If
        Next i

        Console.WriteLine("The data was written and verified.")
    End Sub

End Module

In diesem Beispiel wird der Inhalt einer Datei gelesen und der numerische Wert jedes Bytes im 16-Spalten-Format angezeigt.This example reads the contents of a file and displays each byte's numeric value in 16-column format. Das Ende der Datei, die gelesen wird, wird erkannt, wenn Read die Methode 0 (null) Bytes zurückgibt.The end of the file that is being read is detected when the Read method returns zero bytes.

using System;
using System.IO;
using System.Text;

public class DumpFileSample
{
    private static readonly int CHUNK_SIZE = 1024;
    public static void Main(String[] args)
    {
        if ((args.Length == 0) || !File.Exists(args[0]))
        {
            Console.WriteLine("Please provide an existing file name.");
        }
        else
        {
            using (FileStream fs = new FileStream(args[0], FileMode.Open, FileAccess.Read))
            {
                using (BinaryReader br = new BinaryReader(fs, new ASCIIEncoding()))
                {
                    byte[] chunk;

                    chunk = br.ReadBytes(CHUNK_SIZE);
                    while(chunk.Length > 0)
                    {
                        DumpBytes(chunk, chunk.Length);
                        chunk = br.ReadBytes(CHUNK_SIZE);
                    }
                }
            }
        }
    }

    public static void DumpBytes(byte[] bdata, int len)
    {
        int i;
        int j = 0;
        char dchar;
        // 3 * 16 chars for hex display, 16 chars for text and 8 chars
        // for the 'gutter' int the middle.
        StringBuilder dumptext = new StringBuilder("        ", 16 * 4 + 8);
        for (i = 0; i < len; i++)
        {
            dumptext.Insert(j * 3, String.Format("{0:X2} ", (int)bdata[i]));
            dchar = (char)bdata[i];
            //' replace 'non-printable' chars with a '.'.
            if (Char.IsWhiteSpace(dchar) || Char.IsControl(dchar))
            {
                dchar = '.';
            }
            dumptext.Append(dchar);
            j++;
            if (j == 16)
            {
                Console.WriteLine(dumptext);
                dumptext.Length = 0;
                dumptext.Append("        ");
                j = 0;
            }
        }
        // display the remaining line
        if (j > 0)
        {
            for (i = j; i < 16; i++)
            {
                dumptext.Insert(j * 3, "   ");
            }
            Console.WriteLine(dumptext);
        }
    }
}
Imports System.IO
Imports System.Text

Module Module1
    Private ReadOnly CHUNK_SIZE As Integer = 1024
    Public Sub Main(args() As String)
        If ((args.Length = 0) OrElse Not File.Exists(args(0))) Then
            Console.WriteLine("Please provide an existing file name.")
        Else
            Using fs As FileStream = New FileStream(args(0), FileMode.Open, FileAccess.Read)
                Using br As New BinaryReader(fs, New ASCIIEncoding())
                    Dim chunk(CHUNK_SIZE) As Byte
                    chunk = br.ReadBytes(CHUNK_SIZE)

                    While chunk.Length > 0
                        DumpBytes(chunk, chunk.Length)
                        chunk = br.ReadBytes(CHUNK_SIZE)
                    End While
                End Using
            End Using
        End If
    End Sub

    Public Sub DumpBytes(bdata() As Byte, len As Integer)
        Dim i As Integer
        Dim j As Integer = 0
        Dim dchar As Char
        ' 3 * 16 chars for hex display, 16 chars for text and 8 chars
        ' for the 'gutter' int the middle.
        Dim dumptext As New StringBuilder("        ", 16 * 4 + 8)
        For i = 0 To len - 1
            dumptext.Insert(j * 3, String.Format("{0:X2} ", CType(bdata(i), Integer)))
            dchar = Convert.ToChar(bdata(i))
            ' replace 'non-printable' chars with a '.'.
            If Char.IsWhiteSpace(dchar) Or Char.IsControl(dchar) Then
                dchar = "."
            End If
            dumptext.Append(dchar)
            j += 1
            If j = 16 Then
                Console.WriteLine(dumptext)
                dumptext.Length = 0
                dumptext.Append("        ")
                j = 0
            End If
        Next i
        ' display the remaining line
        If j > 0 Then
            ' add blank hex spots to align the 'gutter'.
            For i = j To 15
                dumptext.Insert(j * 3, "   ")
            Next i
            Console.WriteLine(dumptext)
        End If
    End Sub

End Module

Hinweise

BinaryReaderstellt die Dateiposition nach einem nicht erfolgreichen Lesevorgang nicht wieder her.BinaryReader does not restore the file position after an unsuccessful read operation.

Eine Liste der allgemeinen e/a-Aufgaben finden Sie unter Allgemeine e/a-Aufgaben.For a list of common I/O tasks, see Common I/O Tasks.

Siehe auch

Read(Char[], Int32, Int32) Read(Char[], Int32, Int32) Read(Char[], Int32, Int32) Read(Char[], Int32, Int32)

Liest die angegebene Anzahl von Zeichen beginnend bei einem angegebenen Punkt im Zeichenarray aus dem Datenstrom.Reads the specified number of characters from the stream, starting from a specified point in the character array.

public:
 virtual int Read(cli::array <char> ^ buffer, int index, int count);
public virtual int Read (char[] buffer, int index, int count);
abstract member Read : char[] * int * int -> int
override this.Read : char[] * int * int -> int
Public Overridable Function Read (buffer As Char(), index As Integer, count As Integer) As Integer

Parameter

buffer
Char[]

Der Puffer, in den Daten gelesen werden sollen.The buffer to read data into.

index
Int32 Int32 Int32 Int32

Der Anfangspunkt für das Lesen in den Puffer.The starting point in the buffer at which to begin reading into the buffer.

count
Int32 Int32 Int32 Int32

Die Anzahl der zu lesenden Zeichen.The number of characters to read.

Gibt zurück

Die Gesamtanzahl der in den Puffer gelesenen Zeichen.The total number of characters read into the buffer. Diese kann kleiner sein als die Anzahl der angeforderten Zeichen, wenn gegenwärtig keine entsprechende Anzahl von Bytes verfügbar ist, oder null, wenn das Ende des Streams erreicht ist.This might be less than the number of characters requested if that many characters are not currently available, or it might be zero if the end of the stream is reached.

Ausnahmen

Die Pufferlänge minus index ist kleiner als count.The buffer length minus index is less than count.

- oder --or- Die Anzahl der zu lesenden decodierten Zeichen ist größer als count.The number of decoded characters to read is greater than count. Dies kann geschehen, wenn ein Unicode-Decoder Fallbackzeichen oder ein Ersatzzeichenpaar zurückgibt.This can happen if a Unicode decoder returns fallback characters or a surrogate pair.

index oder count ist ein negativer Wert.index or count is negative.

Ein E/A-Fehler tritt auf.An I/O error occurs.

Beispiele

Im folgenden Beispiel wird gezeigt, wie Sie Daten mit dem Arbeitsspeicher als Sicherungs Speicher lesen und schreiben.The following example shows how to read and write data using memory as a backing store. In diesem Beispiel wird eine Liste der ungültigen Datei Pfad Zeichen in der Konsole angezeigt.This example displays a list of invalid file path characters to the console. Obwohl der Code versucht, eine Liste aller ungültigen Datei Pfad Zeichen anzuzeigen, sind nicht alle Zeichen innerhalb des anzeigbaren Zeichensatzes enthalten.Although the code tries to display a list of all invalid file path characters, not all of the characters are within the displayable set of characters. Da die Liste der ungültigen Zeichen basierend auf dem System variieren kann, kann die Ausgabe für diesen Code ebenfalls variieren.Because the list of invalid characters can vary based on the system, output for this code may also vary.

using namespace System;
using namespace System::IO;
int main()
{
   array<Char>^invalidPathChars = Path::InvalidPathChars;
   MemoryStream^ memStream = gcnew MemoryStream;
   BinaryWriter^ binWriter = gcnew BinaryWriter( memStream );
   
   // Write to memory.
   binWriter->Write( "Invalid file path characters are: " );
   binWriter->Write( Path::InvalidPathChars, 0, Path::InvalidPathChars->Length );
   
   // Create the reader using the same MemoryStream 
   // as used with the writer.
   BinaryReader^ binReader = gcnew BinaryReader( memStream );
   
   // Set Position to the beginning of the stream.
   binReader->BaseStream->Position = 0;
   
   // Read the data from memory and write it to the console.
   Console::Write( binReader->ReadString() );
   int arraySize = (int)(memStream->Length - memStream->Position);
   array<Char>^memoryData = gcnew array<Char>(arraySize);
   binReader->Read( memoryData, 0, arraySize );
   Console::WriteLine( memoryData );
}

using System;
using System.IO;

class BinaryRW
{
    static void Main()
    {
        char[] invalidPathChars = Path.InvalidPathChars;
        MemoryStream memStream = new MemoryStream();
        BinaryWriter binWriter = new BinaryWriter(memStream);

        // Write to memory.
        binWriter.Write("Invalid file path characters are: ");
        binWriter.Write(
            Path.InvalidPathChars, 0, Path.InvalidPathChars.Length);

        // Create the reader using the same MemoryStream 
        // as used with the writer.
        BinaryReader binReader = new BinaryReader(memStream);

        // Set Position to the beginning of the stream.
        memStream.Position = 0;

        // Read the data from memory and write it to the console.
        Console.Write(binReader.ReadString());
        int arraySize = (int)(memStream.Length - memStream.Position);
        char[] memoryData = new char[arraySize];
        binReader.Read(memoryData, 0, arraySize);
        Console.WriteLine(memoryData);
    }
}
Imports System.IO

Public Class BinaryRW

    Shared Sub Main()
    
        Dim invalidPathChars() As Char = Path.InvalidPathChars
        Dim memStream As new MemoryStream()
        Dim binWriter As New BinaryWriter(memStream)

        ' Write to memory.
        binWriter.Write("Invalid file path characters are: ")
        binWriter.Write(Path.InvalidPathChars, 0, _
            Path.InvalidPathChars.Length)

        ' Create the reader using the same MemoryStream 
        ' as used with the writer.
        Dim binReader As New BinaryReader(memStream)

        ' Set Position to the beginning of the stream.
        memStream.Position = 0

        ' Read the data from memory and write it to the console.
        Console.Write(binReader.ReadString())
        Dim upperBound As Integer = _
            CInt(memStream.Length - memStream.Position) - 1
        Dim memoryData(upperBound) As Char
        binReader.Read(memoryData, 0, upperBound)
        Console.WriteLine(memoryData)
    
	End Sub
End Class

Hinweise

BinaryReaderstellt die Dateiposition nach einem nicht erfolgreichen Lesevorgang nicht wieder her.BinaryReader does not restore the file position after an unsuccessful read operation.

Eine Liste der allgemeinen e/a-Aufgaben finden Sie unter Allgemeine e/a-Aufgaben.For a list of common I/O tasks, see Common I/O Tasks.

Siehe auch

Gilt für: