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An Ngo
Posts: 12
Joined: 2006-02-21
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Hi,
I took the sample ExcelAutomationAddIn.
As I see a call to MessageBox.Show (in the exception handle)
(also in the example MyFirstAddIn)
I suppose that MessgaeBox.Show can be used in AddIn module. Is that right?
However, when I put just one MessageBox in the sample ExcelAutomationAddIn
as follow
public string MyFunc(object range)
{
Excel.Range xlRange = null;
string retVal = string.Empty;
try
{
if (range is Excel.Range)
{
// This is the only change I made
MessageBox.Show("What's wrong");
xlRange = range as Excel.Range;
int row = xlRange.Row;
... the rest is the same, I don't touch
the program behaves in a very strange way.
1 - If I type in this formular
=MyFunc(A1:A5)
then the result is normal
2 - But when I click on fx, select the function MyFunc and then use the mouse the select the range, a very strange thing happens:
* Before I can finish the selection, the messagebox just popup, at least twice. It seems that the function is called twice before a soon as I start the selection. And I can never finish the selection using the mouse
* If I give up the mouse, looking carefully at the range, and type the range to the formular then it's OK
Is it a bug? Or something wrong in my using MessageBox inside an AddIn module? Can you show me a walk around? It is impossible to ask the user not to use the mouse to select a range.
Thank you very much
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Eugene Starostin
Guest
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An,
Excel is a multi-threaded application. So, it is a very bad practice to use forms or dialogs inside from your worksheet function. Instead of this, you MUST return #ERR in your retVal. |
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Sergey Grischenko
Add-in Express team
Posts: 7235
Joined: 2004-07-05
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Hi An.
This is not a bug. This is Excel behaviour. I would advise you to use the Debugger to debug Excel Automation add-ins. To return an error message you can use 'return err.Message;' or 'return new ErrorWrapper(err);' code. |
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An Ngo
Posts: 12
Joined: 2006-02-21
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Thank you,
However, I see that you use this MessageBox in your sample, instead of a return code?
I hope that this restriction applied only to Excel Automation Add Ins?
I can still use Forms in other Add In modules? (I see in another sample you use a form in an the Toys example)
Best regards,
An
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Sergey Grischenko
Add-in Express team
Posts: 7235
Joined: 2004-07-05
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Hi An.
Yes, I use the MessageBox but it is not correct way. I will necessarily change this example.
Of course you can use winforms in COM add-ins. |
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