StringReader.ReadAsync Method (Char[], Int32, Int32)

.NET Framework (current version)
 

Reads a specified maximum number of characters from the current string asynchronously and writes the data to a buffer, beginning at the specified index.

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

[<ComVisibleAttribute(false)>]
override ReadAsync : 
        buffer:char[] *
        index:int *
        count:int -> Task<int>

Parameters

buffer
Type: System.Char[]

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.

index
Type: System.Int32

The position in buffer at which to begin writing.

count
Type: System.Int32

The maximum number of characters to read. If the end of the string is reached before the specified number of characters is written into the buffer, the method returns.

Return Value

Type: 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 string has been reached.

Exception Condition
ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

index or count is negative.

ArgumentException

The sum of index and count is larger than the buffer length.

ObjectDisposedException

The string reader has been disposed.

InvalidOperationException

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 string is reached.

The following example shows how to read the first 23 characters of a string asynchronously.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.5
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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