Re: Conversion to VB results in errors - C# Discussion Boards

9-Dec-13 6:39

Dear all

I converted a sample from C# to VB and get an error message. It looks simple, but still I don't understand... Would it be possible that C# allows calling an event directly, while VB doesn't? Or did my conversion tool go wrong? D'Oh! | :doh:

Here's the short sample code:

private void OnWaveControlContextMenuPopup(ContextMenu menu)
 {
   if (this.WControlContextMenuPopup == null)
     return;
   this.WControlContextMenuPopup(menu);
 }

where WControlContextMenuPopup is defined as an event:

public event WControlContextMenuPopupDelegate WaveControlContextMenuPopup;

After conversion I get the error message "Public Event WControlContextMenuPopup in an event and cannot be called directly. Use 'RaiseEvent'...". The error is shown in lines 2 and 5 of the converted code:

Private Sub OnWControlContextMenuPopup(menu As ContextMenu)
    If Me.WControlContextMenuPopup Is Nothing Then             <-----
        Return
    End If
    Me.WControlContextMenuPopup(menu)                          <-----
End Sub

What would I have to change in the VB code to get the required result without error?

Thanks for some insight... Cool | :cool:

Mick

Richard Deeming9-Dec-13 7:26

Richard Deeming

9-Dec-13 7:26

Try something like this:

Private Sub OnWControlContextMenuPopup(menu As ContextMenu)
    RaiseEvent WControlContextMenuPopup(menu) 
End Sub

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Sonhospa9-Dec-13 7:54

9-Dec-13 7:54

Thank you, Richard. Is it correct to leave the "if... end if" part away completely?

Richard Deeming9-Dec-13 8:03

Richard Deeming

9-Dec-13 8:03

Yes, that's correct; RaiseEvent handles that check for you.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Sonhospa9-Dec-13 8:22

9-Dec-13 8:22

Thanks for helping, Richard - have a nice evening! Java | [Coffee]

Dave Kreskowiak9-Dec-13 7:27

Dave Kreskowiak

9-Dec-13 7:27

C# and VB have differing syntax for doing the same thing. C# uses a syntax that is identical to calling an actual method. The error mesage tells you exactly what to do.

RaiseEvent WControlContextMenuPopup(menu)

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Sonhospa9-Dec-13 7:51

9-Dec-13 7:51

Thank you for your answer.

Will I just ignore the whole "If..." part then? Because "If RaiseEvent..." doesn't work either. What is it actually supposed to do? Check for the result of an event???

Dave Kreskowiak9-Dec-13 7:56

Dave Kreskowiak

9-Dec-13 7:56

Yes, you ignore the if code. All it does is check to see if a subscriber is attached before trying to raise the event. If VB.NET, with RaiseEvent, you don't have to do that.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Sonhospa9-Dec-13 8:22

9-Dec-13 8:22

Thank you for your help, and have a nice evening! Thumbs Up | :thumbsup:

Coding Style Questions

Kevin Marois9-Dec-13 6:00

Kevin Marois

9-Dec-13 6:00

1] Data Layers - Would you create one DAL class for each table? Each DAL would have a method for each CRUD operation.

For example I have a series of tables "Extra Work Headers", "Extra Work Material", "Extra Work Equipment"... and a couple more.

Would you put the methods for ALL of the Extra Work tables in one DAL class, or create a DAL class for each?

Right now I have a mix of this. Some DAL's have all methods for a group of tables, but lately I have been creating DAL's for each table.

2] Same question for BL's and Controllers. One Controller for a table group, or a separate Controller for each table?

I see pro's and con's to each approach.

What do you think?

If it's not broken, fix it until it is

PIEBALDconsult9-Dec-13 6:33

PIEBALDconsult

9-Dec-13 6:33

Don't think in terms of "tables", think in terms of "operations" -- many operations require changes to multiple tables.

Kevin Marois9-Dec-13 6:59

Kevin Marois

9-Dec-13 6:59

While I agree, part of the reason I'm asking is that I'm using a home grown tool that generates code. It creates the Table Scripts, Entities, DAL, BL, Controllers, Models, API Proxy code, etc.

Not sure how that would work from an 'Operation' based approach.

So what I think I hear you saying is to create these objects based on what needs to be done, rather than based off the table?

If it's not broken, fix it until it is

PIEBALDconsult9-Dec-13 9:30

PIEBALDconsult

9-Dec-13 9:30

That's what I'm saying.

Kevin Marois wrote:
home grown tool

I'm all for that. Thumbs Up | :thumbsup:

Kevin Marois wrote:
Not sure how that would work from an 'Operation' based approach.

Which is why I never use anything that claims it can do it. There is no substitute for hard work. Doing it the right way requires time and experience.

Kevin Marois9-Dec-13 9:51

Kevin Marois

9-Dec-13 9:51

I'm working on a long term project. If I tailored the tool specifically for this project, I could make it work

If it's not broken, fix it until it is

PIEBALDconsult9-Dec-13 10:02

PIEBALDconsult

9-Dec-13 10:02

I'm sure you'll learn things along the way, and that's a good thing. Java | [Coffee]

Persists GridView Textbox Value

V.9-Dec-13 20:51

9-Dec-13 20:51

It kinda depends I guess. For example: When you have tables where each record is considered an "object". You should use one class/table. Examples: Persons, tickets, companies, products, ... things like that.

If you have tables that start having calculations or objects that are (complex) joins of tables or where multiple records can makeup one record, you should probably tackle that a little differently.

hope this helps.

V.

(MQOTD Rules and previous Solutions )

Eye tracking code

polycom1239-Dec-13 5:44

polycom123

9-Dec-13 5:44

Hello,
Does anybody know of a good code that can help with an eye tracking with a webcam?

I found only one code (TrackEye : Real-Time Tracking Of Human Eyes Using a Webcam) but it is from 5 years ago.

Basiclly, I'm looking for something to help a disable man to comunicate.

Thanks.

wernlin9-Dec-13 5:22

wernlin

9-Dec-13 5:22

How to persists gridview textbox value when paging.
My situation is after user entered text in textbox they will click on the button to check their answer. But after i click gridview next page the previous page textbox value is not keep.

Thanks.

c# listview insert not working

dbushong9-Dec-13 4:11

dbushong

9-Dec-13 4:11

I am trying to insert (not add) data to a listview. The listview has 7 cols.
The code I am using is:

ListViewItem item = lvBOM.Items[2];

lvBOM.Items.Insert(2,"Hi");

This code is activated by a button click. The result is that a row is inserted but the word "HI" does not appear.
Full row select is set to true.
c# 2013 framework 4.51. Desktop app.

Thank you,
Duke

modified 9-Dec-13 10:43am.

Richard MacCutchan9-Dec-13 5:37

Richard MacCutchan

9-Dec-13 5:37

I just tried that and it worked fine, is there something else that you are doing?

Veni, vidi, abiit domum

dbushong9-Dec-13 5:51

dbushong

9-Dec-13 5:51

Thank you for replying.
The app has 2 listviews. The lvBOM listview has 7 cols.
I have supplied test data to all 70 rows in the first col only.
Here is the code for that:

for (int i = 0; i < intRCount; i++)
{
ListViewItem myItem = lvBOM.Items[i];//row
myItem.SubItems[1].Text = "5";//col

}
In the same button_click I followed that code with this code:

ListViewItem item = lvBOM.Items[2];//row

lvBOM.Items.Insert(2,"Hi");

The result is that the row is inserted but the data does not show. This data is test and only used to test the insert function.

Richard MacCutchan9-Dec-13 6:13

Richard MacCutchan

9-Dec-13 6:13

I have four rows and three columns in my control. When I press the button it runs the following code:

ListViewItem item = listView1.Items[2];//row
listView1.Items.Insert(2, "Hi");

The row is added, and the word "Hi" appears in column 1. I can only assume that there is something in your code that you have not shown us, which is causing a problem.

Veni, vidi, abiit domum