• Article

TextReader.ReadBlock Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

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)

Syntax

'Declaration
Public Overridable Function ReadBlock ( _
    <OutAttribute> buffer As Char(), _
    index As Integer, _
    count As Integer _
) As Integer

public virtual int ReadBlock(
    char[] buffer,
    int index,
    int count
)

Parameters

  • buffer
    Type: array<System.Char[]
    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.
  • index
    Type: System.Int32
    The place in buffer at which to begin writing.
  • count
    Type: System.Int32
    The maximum number of characters to read.

Return Value

Type: System.Int32
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.

Exceptions

Exception Condition
ArgumentNullException

buffer is nulla null reference (Nothing in Visual Basic).
ArgumentException

The buffer length minus index is less than count.
ArgumentOutOfRangeException

index or count is negative.
ObjectDisposedException

The TextReader is closed.
IOException

An I/O error occurs.

Remarks

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

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.