TextReader.ReadAsync Method (Char, Int32, Int32)
Reads a specified maximum number of characters from the current text reader asynchronously and writes the data to a buffer, beginning at the specified index.
Assembly: mscorlib (in mscorlib.dll)
[ComVisibleAttribute(false)] [HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public virtual Task<int> ReadAsync( char buffer, int index, int count )
When this method returns, contains the specified character array with the values between index and (index + count - 1) replaced by the characters read from the current source.
The position in buffer at which to begin writing.
The maximum number of characters to read. If the end of the text is reached before the specified number of characters is read into the buffer, the current method returns.
Return ValueType: System.Threading.Tasks.Task<Int32>
A task that represents the asynchronous read operation. The value of the TResult parameter contains the total number of bytes read into the buffer. The result value can be less than the number of bytes requested if the number of bytes currently available is less than the requested number, or it can be 0 (zero) if the end of the text has been reached.
buffer is null.
index or count is negative.
The sum of index and count is larger than the buffer length.
The text reader has been disposed.
The reader is currently in use by a previous read operation.
The task completes after either the number of characters specified by the count parameter are read or the end of the file is reached.
Available since 8
Available since 4.5
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Available since 8.1