FileStream::EndRead Method
Waits for the pending asynchronous read to complete.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- asyncResult
- Type: System::IAsyncResult
The reference to the pending asynchronous request to wait for.
Return Value
Type: System::Int32The number of bytes read from the stream, between 0 and the number of bytes you requested. Streams only return 0 at the end of the stream, otherwise, they should block until at least 1 byte is available.
| Exception | Condition |
|---|---|
| ArgumentNullException | asyncResult is nullptr. |
| ArgumentException | This IAsyncResult object was not created by calling BeginRead on this class. |
| InvalidOperationException | EndRead is called multiple times. |
| IOException | The stream is closed or an internal error has occurred. |
EndRead must be called exactly for every call to BeginRead. Failing to end a read process before beginning another read can cause undesirable behavior such as deadlock.
This method overrides EndRead.
EndRead can be called on every IAsyncResult from BeginRead. Calling EndRead tells you how many bytes were read from the stream. EndRead will block until the I/O operation has completed.
For a list of common I/O tasks, see Common I/O Tasks.
Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows CE Platform Note: In .NET Compact Framework applications, this method is supported, but it is reserved for future use. Using this method will raise a NotSupportedException until it becomes available in a future release.
This code example is part of a larger example provided for the FileStream(String, FileMode, FileAccess, FileShare, Int32, Boolean) constructor.
static void EndReadCallback( IAsyncResult^ asyncResult ) { State^ tempState = dynamic_cast<State^>(asyncResult->AsyncState); int readCount = tempState->FStream->EndRead( asyncResult ); int i = 0; while ( i < readCount ) { if ( tempState->ReadArray[ i ] != tempState->WriteArray[ i++ ] ) { Console::WriteLine( "Error writing data." ); tempState->FStream->Close(); return; } } Console::WriteLine( "The data was written to {0} " "and verified.", tempState->FStream->Name ); tempState->FStream->Close(); // Signal the main thread that the verification is finished. tempState->ManualEvent->Set(); } public:
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.