StreamReader.ReadLine抛出一个奇怪的ArgumentOutOfRangeException

Question

I'm using a StreamReader on a large text-file (~300 MB) and calling ReadLine() in a loop eventually throws a weird ArgumentOutOfRangeException :

Index and count must refer to a location within the buffer.
Parameter name: bytes

The stacktrace is:

at System.Text.DecoderNLS.GetChars(Byte[] bytes, Int32 byteIndex, Int32 byteCount,
Char[] chars, Int32 charIndex, Boolean flush)
at System.Text.DecoderNLS.GetChars(Byte[] bytes, Int32 byteIndex, Int32 byteCount,
Char[] chars, Int32 charIndex)
at System.IO.StreamReader.ReadBuffer()
at System.IO.StreamReader.ReadLine()
....

Is this some weird memory error? It doesn't throw OutOfMemoryException so I'm a bit lost. It happens around the 2000th line. By that time, even if it continues with a successful ReadLine(), it starts throwing weird exceptions elsewhere. So there's a probably memory leak somewhere, but is there anything specific to ReadLine() or StreamReader to look at?

Each line in my text file is exactly 24 characters long.

Answer 1

If the problem is specific to StremReader.ReadLine() it may be:

• the number of characters in the next line is larger than Int32.MaxValue
• the buffer you passed to StremReader constructor is too small