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TextReader.ReadLine Method

Reads a line of characters from the current stream and returns the data as a string.

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

public virtual string ReadLine()

Return Value

Type: System.String
The next line from the input stream, or null if all characters have been read.

ExceptionCondition
IOException

An I/O error occurs.

OutOfMemoryException

There is insufficient memory to allocate a buffer for the returned string.

ObjectDisposedException

The TextReader is closed.

ArgumentOutOfRangeException

The number of characters in the next line is larger than MaxValue

A line is defined as a sequence of characters followed by a carriage return (0x000d), a line feed (0x000a), a carriage return followed by a line feed, Environment.NewLine, or the end of stream marker. The string that is returned does not contain the terminating carriage return and/or line feed. The returned value is null if the end of the input stream has been reached.

If the current method throws an OutOfMemoryException, the reader's position in the underlying Stream is advanced by the number of characters the method was able to read, but the characters already read into the internal ReadLine buffer are discarded. Since the position of the reader in the stream cannot be changed, the characters already read are unrecoverable, and can be accessed only by reinitializing the TextReader. If the initial position within the stream is unknown or the stream does not support seeking, the underlying Stream also needs to be reinitialized.

To avoid such a situation and produce robust code you should use the Read method and store the read characters in a preallocated buffer.

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

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

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