Asynchronous Writing, Asynchronous Reading : Asynchronous Input output « File Stream « C# / C Sharp






Asynchronous Writing, Asynchronous Reading

//Code revised from Chapter 25 - Accessing Data Streams
//C# Bible
//by Jeff Ferguson et al. 


using System;
using System.IO;
using System.Threading;
   
class FileTestClass
{
    private static FileStream    BinaryFile = new FileStream("test.dat", FileMode.Create, FileAccess.ReadWrite);
    private static byte []       ByteArray = new byte [256];
    private static IAsyncResult  AsyncReadResultImplementation = null;
    private static IAsyncResult  AsyncWriteResultImplementation;
    private static AsyncCallback ReadBytesCompleteCallback = new AsyncCallback(OnReadBytesComplete);
    private static AsyncCallback WriteBytesCompleteCallback = new AsyncCallback(OnWriteBytesComplete);
    
   
    public static void OnReadBytesComplete(IAsyncResult AsyncResult)
    {
        int BytesRead;
        int Failures;
   
        BytesRead = BinaryFile.EndRead(AsyncResult);
        Console.WriteLine("Bytes read........: {0}", BytesRead);
        Failures = 0;
        for(int i = 0; i < 256; i++)
        {
            if(ByteArray[i] != (byte)i)
            {
                Console.WriteLine("Read test failed for byte at offset {0}.", i);
                Failures++;
            }
        }
        Console.WriteLine("Read test failures: {0}", Failures);
    }
    public static void OnWriteBytesComplete(IAsyncResult AsyncResult)
    {
        BinaryFile.EndWrite(AsyncResult);
    }
    static public void Main()
    {
        for(int i = 0; i < 256; i++)
            ByteArray[i] = (byte)i;
        AsyncWriteResultImplementation = BinaryFile.BeginWrite(ByteArray, 0, 256, WriteBytesCompleteCallback, null);


        WaitHandle WaitOnWriteIO = AsyncWriteResultImplementation.AsyncWaitHandle;
        WaitOnWriteIO.WaitOne();


        BinaryFile.Seek(0, SeekOrigin.Begin);
        AsyncReadResultImplementation = BinaryFile.BeginRead(ByteArray, 0, 256, ReadBytesCompleteCallback, null);

        WaitHandle WaitOnReadIO = AsyncReadResultImplementation.AsyncWaitHandle;
        WaitOnReadIO.WaitOne();
    }
}

           
       








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