C# vba development

I created a button, to dynamically create a validation on cell

the following is the code i wrote:

......

Excel.Range thisRange =
((Excel.Worksheet)(this.thisWorkbook.Worksheets.get_Item("XXXXX"))).get_Range("A1", Type.Missing);

thisRange.Validation.Add(Excel.XlDVType.xlValidateList,
Excel.XlDVAlertStyle.xlValidAlertStop,
Excel.XlFormatConditionOperator.xlBetween,"Yes, No", Type.Missing);

......

I tested, and found that thisRange is not null and thisRange.Validation is
not null either. However, when i wrong the code, and clicked the button, it
tells me "Object Reference is Not set to an instance of an object".

But the range object is not, while validation is not null either. Can anyone
help me solve this problem?

Many thanks

Foeyshell,
You are automating Excel from C# ?
If so, may be microsoft.public.dotnet.languages.csharp would be a better
place.

NickHK

"Foeyshell" <[email protected]> wrote in message
news:[email protected]...
> I created a button, to dynamically create a validation on cell
>
> the following is the code i wrote:
>
> .....
>
> Excel.Range thisRange =
>
((Excel.Worksheet)(this.thisWorkbook.Worksheets.get_Item("XXXXX"))).get_Rang
e("A1", Type.Missing);
>
> thisRange.Validation.Add(Excel.XlDVType.xlValidateList,
> Excel.XlDVAlertStyle.xlValidAlertStop,
> Excel.XlFormatConditionOperator.xlBetween,"Yes, No", Type.Missing);
>
> .....
>
> I tested, and found that thisRange is not null and thisRange.Validation is
> not null either. However, when i wrong the code, and clicked the button,
it
> tells me "Object Reference is Not set to an instance of an object".
>
> But the range object is not, while validation is not null either. Can
anyone
> help me solve this problem?
>
> Many thanks

Hi Foeyshell,

> I created a button, to dynamically create a validation on cell
>
> the following is the code i wrote:
>
> ......
>
> Excel.Range thisRange =
> ((Excel.Worksheet)(this.thisWorkbook.Worksheets.get_Item("XXXXX"))).get_Range("A1", Type.Missing);
>
> thisRange.Validation.Add(Excel.XlDVType.xlValidateList,
> Excel.XlDVAlertStyle.xlValidAlertStop,
> Excel.XlFormatConditionOperator.xlBetween,"Yes, No", Type.Missing);
>
> ......
>
> I tested, and found that thisRange is not null and thisRange.Validation is
> not null either. However, when i wrong the code, and clicked the button, it
> tells me "Object Reference is Not set to an instance of an object".
>
> But the range object is not, while validation is not null either. Can anyone
> help me solve this problem?

This looks like a VSTO project. If so, the appropriate newsgroup is
Microsoft.public.vsnet.vstools.office.

Regards

Stephen Bullen
Microsoft MVP - Excel
www.oaltd.co.uk