ReadBlock Method

TextReader.ReadBlock Method

Reads a maximum of count characters from the current stream, and writes the data to buffer, beginning at index.

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

public virtual int ReadBlock (
	[InAttribute] [OutAttribute] char[] buffer,
	int index,
	int count
public int ReadBlock (
	/** @attribute InAttribute() */ /** @attribute OutAttribute() */ char[] buffer, 
	int index, 
	int count
public function ReadBlock (
	buffer : char[], 
	index : int, 
	count : int
) : int
Not applicable.



When this method returns, this parameter contains the specified character array with the values between index and (index + count -1) replaced by the characters read from the current source.


The place in buffer at which to begin writing.


The maximum number of characters to read.

Return Value

The position of the underlying stream is advanced by the number of characters that were read into buffer. The number of characters that have been read. The number will be less than or equal to count, depending on whether all input characters have been read.

Exception typeCondition


buffer is a null reference (Nothing in Visual Basic).


The buffer length minus index is less than count.


index or count is negative.


The TextReader is closed.


An I/O error occurs.

The method blocks until either count characters are read, or all characters have been read. This is a blocking version of Read.

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

Community Additions

© 2015 Microsoft