I'm trying to implement a simple command line program to make an
asynchronus method call.
The calls all seem to work but they appear to be synchronous. In the code
below, I was expect to see the Console echo the text "before call"
and "after call" prior to the method called by the async delegate
completing. However, the "after call" doesn't seem to write until after the
async stuff finishes. So, this looks to me to be doing nothing more that a
synchronous call would. What am I doing wrong here? Thanks....
Here's the code:
using System;
namespace AsyncFormatsNET
{
delegate void Working();
class twFormats
{
public void Format()
{
//Sync Call - IL calls Invoke() method of delegate
//if (OnFormatting != null) OnFormatting();
//Async call - BeginInvoke() method of delegate
if (OnFormatting != null)
{
foreach(Working FormattingDelegate in OnFormatting.GetInvocationList())
{
//fire and poll for result
IAsyncResult AsyncProxyResult = FormattingDelegate.BeginInvoke
(null,null);
while(!AsyncProxyResult.IsCompleted)
{
Console.WriteLine("Asychronous call to twFormatsProxy.CallProxy NOT
completed yet");
System.Threading.Thread.Sleep(1000);
}
FormattingDelegate.EndInvoke(AsyncProxyResult);
Console.WriteLine("Asychronous call to twFormatsProxy.CallProxy
completed");
}
}
}
public event Working OnFormatting;
}
class twFormatsProxyInterop
{
public void CallProxy()
{
//To Do: add proxy call
Console.WriteLine("Proxy called");
//Simulate a 5 second proxy call
System.Threading.Thread.Sleep(5000);
}
}
//Client
class twExecFormats
{
static void Main()
{
twFormats twf = new twFormats();
twFormatsProxyInterop twi = new twFormatsProxyInterop();
twf.OnFormatting += new Working(twi.CallProxy);
Console.WriteLine("Before call");
twf.Format(); /*I was expected this line to fire and the have exectution
proceed immediately to the next line, but the code seems to get stuck here
util the call completes???????*/
Console.WriteLine("After call");
}
}
}
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