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BinaryReader.ReadInt64 Method

Reads an 8-byte signed integer from the current stream and advances the current position of the stream by eight bytes.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

public virtual long ReadInt64 ()
public long ReadInt64 ()
public function ReadInt64 () : long

Return Value

An 8-byte signed integer read from the current stream.

Exception typeCondition


The end of the stream is reached.


The stream is closed.


An I/O error occurs.

BinaryReader does not restore the file position after an unsuccessful read.

BinaryReader reads this data type in little-endian format.

The following table lists examples of other typical or related I/O tasks.

To do this...

See the example in this topic...

Create a text file.

How to: Write Text to a File

Write to a text file.

How to: Write Text to a File

Read from a text file.

How to: Read Text from a File

Append text to a file.

How to: Open and Append to a Log File



Get the size of a file.


Get the attributes of a file.


Set the attributes of a file.


Determine if a file exists.


Read from a binary file.

How to: Read and Write to a Newly Created Data File

Write to a binary file.

How to: Read and Write to a Newly Created Data File

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
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