Anonymous Method Sample

[Nick]

Hi,
I was just playing around and found that the following two ways of
calling the same method using the WaitCallback method that takes an
object parameter. Can any one explain why there is no problem with the
first call even though the delegate doesn't take in the Object
Parameter??? What is the complier doing "under the covers".

Thanks for any help
Nick

Object state = new Object();
// Using WaitCallback
// Note no parameter passed in
WaitCallback oInvokeNoParame ter = delegate {
MyMethodCall(); };
oInvokeNoParame ter.Invoke(stat e);


WaitCallback oInvokeAParamet er = delegate(Object oObject) {
MyMethodCall(); };
oInvokeAParamet er.Invoke(state );

.......
static void MyMethodCall()
{
Console.WriteLi ne("MyMethodCal l has been invoked");
}

[Dustin Campbell]

Re: Anonymous Method Sample

Hi,

I was just playing around and found that the following two ways of
calling the same method using the WaitCallback method that takes an
object parameter. Can any one explain why there is no problem with
the
first call even though the delegate doesn't take in the Object
Parameter??? What is the complier doing "under the covers".
Thanks for any help
Nick
Object state = new Object();
// Using WaitCallback
// Note no parameter passed in
WaitCallback oInvokeNoParame ter = delegate {
MyMethodCall(); };
oInvokeNoParame ter.Invoke(stat e);
WaitCallback oInvokeAParamet er = delegate(Object oObject)
{
MyMethodCall(); };
oInvokeAParamet er.Invoke(state );
......
static void MyMethodCall()
{
Console.WriteLi ne("MyMethodCal l has been invoked");
}

The compiler is still generating the same WaitCallback delegate with a state
parameter under the covers. However, with an anonymous method, you aren't
required to actually declare the parameters unless you use them in the anonymous
method's body.

Best Regards,
Dustin Campbell
Developer Express Inc.

[Brian Gideon]

Re: Anonymous Method Sample

Nick,

This is called delegate inference. See the following article for more
information.

http://www.yoda.arachsys.com/csharp/csharp2/delegates.html

Brian

Nick wrote:

Hi,
I was just playing around and found that the following two ways of
calling the same method using the WaitCallback method that takes an
object parameter. Can any one explain why there is no problem with the
first call even though the delegate doesn't take in the Object
Parameter??? What is the complier doing "under the covers".
>
Thanks for any help
Nick
>
Object state = new Object();
// Using WaitCallback
// Note no parameter passed in
WaitCallback oInvokeNoParame ter = delegate {
MyMethodCall(); };
oInvokeNoParame ter.Invoke(stat e);
>
>
WaitCallback oInvokeAParamet er = delegate(Object oObject) {
MyMethodCall(); };
oInvokeAParamet er.Invoke(state );
>
......
static void MyMethodCall()
{
Console.WriteLi ne("MyMethodCal l has been invoked");
}

[William Stacey [C# MVP]]

Re: Anonymous Method Sample

Also, if method was "static void MyMethodCall(ob ject value){}",
you could also do:

WaitCallback cb = MyMethodCall;
cb(null);

--
William Stacey [C# MVP]

"Nick" <nick_tucker@ho tmail.comwrote in message
news:1161866896 .722159.151250@ k70g2000cwa.goo glegroups.com.. .
| Hi,
| I was just playing around and found that the following two ways of
| calling the same method using the WaitCallback method that takes an
| object parameter. Can any one explain why there is no problem with the
| first call even though the delegate doesn't take in the Object
| Parameter??? What is the complier doing "under the covers".
|
| Thanks for any help
| Nick
|
| Object state = new Object();
| // Using WaitCallback
| // Note no parameter passed in
| WaitCallback oInvokeNoParame ter = delegate {
| MyMethodCall(); };
| oInvokeNoParame ter.Invoke(stat e);
|
|
| WaitCallback oInvokeAParamet er = delegate(Object oObject) {
| MyMethodCall(); };
| oInvokeAParamet er.Invoke(state );
|
| ......
| static void MyMethodCall()
| {
| Console.WriteLi ne("MyMethodCal l has been invoked");
| }
|