.net prevent CA1009 - declare the first parameter of 'myclass.mymethod' as an object named 'sender'

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Hello.

I've this code in my .NET project:

C#

public delegate void CtrlVisible(Boolean v);

inside of a class which doesn't implements EventArgs.
I use it in this way:

rs.ctrlVisible += new clsReportStatus.CtrlVisible(rs_ctrlVisible);

where rs_ctrlVisible is:

C#

public event CtrlVisible ctrlVisible;

How should I fix that problem?

Thanks.

What I have tried:

Tried reading MSFT documentation about event driven development.
Casting instances to object and then converting them to Boolean again.

Posted 10-Apr-17 5:08am

Member 13118954

Updated 10-Apr-17 5:37am

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[no name] 10-Apr-17 11:18am

https://msdn.microsoft.com/en-us/library/ms182133.aspx

Member 13118954 10-Apr-17 11:30am

the first thing I did was RTFM, if I asked here it was because I couldn't solve it by reading the MSFTs documentation

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OriginalGriff · Accepted Answer · 2017-04-10T05:37:00

Solution 1

"Events are a special kind of multicast delegate that can only be invoked from within the class or struct where they are declared." - MSDN.

What that means is that the signature of a delegate that can be used as an event must match that of all events: an object sender, and a EventArgs derived class instance.
A bool is not suitable: it doesn't match the event signature.

Change your delegate as the error message suggested.

Posted 10-Apr-17 5:37am

OriginalGriff

Comments

Member 13118954 10-Apr-17 11:57am

Hey @OriginalGriff

But I need to check the value of my boolean variable in order to make a progress bar visible or not.

private void rs_ctrlVisible(bool v)
{
	try
	{
		if (this.InvokeRequired)
		{
			MethodInvoker del = delegate { rs_ctrlVisible(v); };
			this.Invoke(del);
		}
		else
		{
			progressBar1.Visible = v;
		}
	}
	catch
	{

	}
}

How could I achieve that functionality using object and EventArgs arguments?

Regards.

Regards.

OriginalGriff 10-Apr-17 12:11pm

Declare a new EventArgs class that derives from EventArgs, and put your boolean value inside that.

Member 13118954 10-Apr-17 12:34pm

Seems to be the best option. I Will investigate more about that.

thank you

OriginalGriff 10-Apr-17 13:57pm

You're welcome!

Richard Deeming 11-Apr-17 14:01pm

"the signature of a delegate that can be used as an event must match that of all events"

Technically, that "must" should be a "should". It's perfectly possible - but definitely not recommended - to create events using delegates that don't follow the standard .NET signature - for example, lots of COM libraries do just that.

CA1009 is an FxCop warning, not a compiler error. :)