What's wrong with this code?

[Kristian Sixhoj]

don234564 wrote:

Parameter count mismatch

The error message always tells you the problem. In this case, the number of parameters passed to the method is incorrect. I don't know that method you're using, though, so I can't help you with that.

Kristian Sixhoej "You can't undo the past... but you can certainly not repeat it." - Bruce Willis

[Rob Philpott]

Looks alright to me, I have to say. What is lvThreads?

Regards, Rob Philpott.

[Luc Pattyn]

don234564 wrote:

new object[] { data }

data already is an object array, why create a new array holding this one array as its sole element? BTW: there is no need to create the delegate over and over again, you can move the statement _Post_Result upd = new _Post_Result(Post_Result); elsewhere (e.g. as a class member) and execute it only once. :)

Luc Pattyn [Forum Guidelines] [My Articles]

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modified on Friday, June 10, 2011 11:38 AM

[Rob Philpott]

I think I must be missing something here - I can't see what's wrong with the code. You create a new array holding the array as it's only element because that's the signature Control.Invoke expects. The array represents individual parameters, the fact there's only one and that it is itself an array is irrelevant. But then, I think it should work so don't listen to me... :doh:

Regards, Rob Philpott.

[Juvil John]

im confused either where im getting this wrong... anyone can try the code?

[Juvil John]

yes data is already an array. parameter in control.invoke refers to the number of parameters you pass this through in that case "upd" which is refered to Post_Results which contains only 1 param so thats the reason why you have to place the data into another array.

[Wendelius]

Never run into this situation but could you try what happens if you define the delegate as public. Also as others pointed out, I don't see a reason to create a new array.

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[martin_hughes]

I suspect that the exception is not being thrown here:

don234564 wrote:

this.lvThreads.Invoke(upd, new object[] { data });

but somewhere here:

don234564 wrote:

ListViewItem lvitem = (ListViewItem)data[0]; this.lvThreads.Items[lvitem.Text].SubItems[1].Text = Convert.ToString(data[1]);

And what you're actually experiencing is one of the whole panoply of wonders associated with multi-threading.

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[Juvil John]

I have not actually found out whats really causing this but I re design my code and somehow got this to work. here's what i'm using now.

private delegate void _Post_Result(object data);

    private void Post\_Result(object data)
    {
        if (lvThreads.InvokeRequired)
        {
            //This means that calling was accessed in separate thread
            upd = new \_Post\_Result(Post\_Result);
            this.lvThreads.Invoke(upd, new object\[\] { data });
        }
        else
        {
            //This means that calling of lvThreads is in main thread
            lvitem = (ListViewItem)data;
            this.lvThreads.Items\[lvitem.Index\].SubItems\[1\].Text = 
                Convert.ToString(Convert.ToInt32(lvitem.SubItems\[1\].Text) + 1);
        }
    }

[Jon Rista]

You have to create a new array because the outer array is the array of parameters TO PASS TO the called function, and the inner array IS the first parameter OF the called function. Since the called function takes an array as its first parameter...

[Wendelius]

Wouldn't casting work in this situation? this.lvThreads.Invoke(upd, (object[])data);

The need to optimize rises from a bad design.My articles[^]