Access a COM Component Library

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Bradley Grant - 26 Jan 2004 04:11 GMT

I'm trying to access a COM Component with C#. And I get the following error

C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(172): Method 'USB.Form1.button5_OnChange(object, System.EventArgs)' does not match delegate 'void BDaq._IBBDaqEnumEvents_OnChangeEventHandler()

C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(173): Method 'USB.Form1.button5_OnChange(object, System.EventArgs)' does not match delegate 'void BDaq._IBBDaqDeviceEvents_OnChangeEventHandler()

I created the Object a Delegate and a method, I believe the problem is the augument in the method button5_OnChange(object sender, System.EventArgs e) but I'm not sure what I should put there, here is some of the code

Any suggestions would be appreciated

public class Form1 : System.Windows.Forms.For
    {
        private BDaq.BBDaqEnum Connected = new BDaq.BBDaqEnum()
        private BDaq.BBDaqDevice Device1 = new BDaq.BBDaqDevice()

    public Form1(
    {
        InitializeComponent()

        Connected.OnChange += new BDaq._IBBDaqEnumEvents_OnChangeEventHandler(button5_OnChange)
        Device1.OnChange += new BDaq._IBBDaqDeviceEvents_OnChangeEventHandler(button5_OnChange)


private void button5_OnChange( object sender, System.EventArgs e

        Do somethin

Reply to this Message

Uwe Hafner - 27 Jan 2004 16:28 GMT

Hi,

probably your method button5_OnChange does not have the same signature as
the delegate (i.e. the same arguments and return value).

What does the delegate declaration look like? Make button5_OnChange look the
same.

hth
Uwe

it usually means your eventhandler does not have the correct signature. It
has to look like the delegate declaration

> I'm trying to access a COM Component with C#. And I get the following error.
>
> C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(172): Method 'USB.Form1.button5_OnChange(object, System.EventArgs)' does not match

delegate 'void BDaq._IBBDaqEnumEvents_OnChangeEventHandler()'

> C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(173): Method 'USB.Form1.button5_OnChange(object, System.EventArgs)' does not match

delegate 'void BDaq._IBBDaqDeviceEvents_OnChangeEventHandler()'

> I created the Object a Delegate and a method, I believe the problem is the augument in the method button5_OnChange(object sender, System.EventArgs

e) but I'm not sure what I should put there, here is some of the code.

> Any suggestions would be appreciated.
>
[quoted text clipped - 15 lines]
> Do something
> }

Reply to this Message

Bradley - 27 Jan 2004 17:26 GMT

Thank for your reply, I guess that is the question I'm asking what the signature, argument in the button5_OnChange method should look like. My guess is that object sender, System.EventArgs e, is the usual standard that Visual studio puts there, that it is the standard for Net components, but not for the COM Component that I am trying to access. I guess I just do not have enough understanding in this area, and if you have any ideas or books or know of any resources that I might learn more about this, I would be interested. Thanks again for your reply

----- Uwe Hafner wrote: ----

Hi

probably your method button5_OnChange does not have the same signature a
the delegate (i.e. the same arguments and return value)

What does the delegate declaration look like? Make button5_OnChange look th
same

ht
Uw

it usually means your eventhandler does not have the correct signature. I
has to look like the delegate declaratio
"Bradley Grant" <bradgrant@shaw.ca> schrieb im Newsbeitra
news:96BC34BD-7108-475E-B592-FF45E9A7E863@microsoft.com..
> I'm trying to access a COM Component with C#. And I get the followin
error
>> C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(172): Metho
'USB.Form1.button5_OnChange(object, System.EventArgs)' does not matc
delegate 'void BDaq._IBBDaqEnumEvents_OnChangeEventHandler()
>> C:\Visual C# Step by Step\Lesson 1\USB\Form1.cs(173): Metho
'USB.Form1.button5_OnChange(object, System.EventArgs)' does not matc
delegate 'void BDaq._IBBDaqDeviceEvents_OnChangeEventHandler()
>> I created the Object a Delegate and a method, I believe the problem i
the augument in the method button5_OnChange(object sender, System.EventArg
e) but I'm not sure what I should put there, here is some of the code
>> Any suggestions would be appreciated
>> public class Form1 : System.Windows.Forms.For
>
> private BDaq.BBDaqEnum Connected = new BDaq.BBDaqEnum()
> private BDaq.BBDaqDevice Device1 = new BDaq.BBDaqDevice()
>
> public Form1(
>
> InitializeComponent()
>> Connected.OnChange += ne
BDaq._IBBDaqEnumEvents_OnChangeEventHandler(button5_OnChange)
> Device1.OnChange += ne
BDaq._IBBDaqDeviceEvents_OnChangeEventHandler(button5_OnChange)
>
>>> private void button5_OnChange( object sender, System.EventArgs e
>
> Do somethin

Reply to this Message

Uwe Hafner - 28 Jan 2004 08:47 GMT

Hi,

The error message should give you some hints. If that is the full error
message it looks like your Event does not have any arguments and return
values. Otherwise it might look like this (example):
Method 'USB.Form1.button5_OnChange(object, System.EventArgs)' does not match
delegate 'void BDaq._IBBDaqDeviceEvents_OnChangeEventHandler(object)'
In which case it would expect an object as argument.

If you have VS.NET 2003 the IDE can make the declarations for you. Just
enter

myClass.MyEvent +=

After the "=" sign the tooltip should ask you to push "Tab" to finish the
line for you like this:
myClass. MyEvent += new Handler(myHandler)
Then it will have a second tooltip and it asks you again to push "Tab" to
make a method declaration "myHandler" for you.

Most times you should get the information about the signature from
documentation of the COM Object you are using. Maybe you can get some
information from the object browser but I am not sure if it shows this info.

hth
Uwe

> Thank for your reply, I guess that is the question I'm asking what the signature, argument in the button5_OnChange method should look like. My

guess is that object sender, System.EventArgs e, is the usual standard that
Visual studio puts there, that it is the standard for Net components, but
not for the COM Component that I am trying to access. I guess I just do not
have enough understanding in this area, and if you have any ideas or books
or know of any resources that I might learn more about this, I would be
interested. Thanks again for your reply.

> ----- Uwe Hafner wrote: -----
>
[quoted text clipped - 42 lines]
> > Do something
> > }

Reply to this Message

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