Excel with Reflection

Pascal Beer

Hi
I'm trying to export some data into an excel sheet (office version 2010). I want do this with Reflection. I've tried following:

Type excelType = Type.GetTypeFromProgID("Excel.Application");
object objExcel = Activator.CreateInstance(excelType);
object objBooks = objExcel.GetType().GetProperty("Workbooks").GetValue(objExcel, null);
object objBook = objBooks.GetType().InvokeMember("Add", BindingFlags.InvokeMethod, null, objBooks, new[] { Missing.Value });
object objSheet = objBook.GetType().GetProperty("Worksheets").GetValue(objBook, null);

At the last line the code crashs cause objBook.GetType().GetProperty("Worksheets") returns null.
What is wrong here?
Regards

6 Replies

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Vulpes14y ago
Accepted answer
The problem is that you can't use the GetProperty() method here - you have to use InvokeMember() with BindingFlags.GetProperty instead.

To obtain the first WorkSheet, try it like this:

Type excelType = Type.GetTypeFromProgID("Excel.Application");
object objExcel = Activator.CreateInstance(excelType);
object objBooks = objExcel.GetType().InvokeMember("Workbooks", BindingFlags.GetProperty, null, objExcel, null);
object objBook = objBooks.GetType().InvokeMember("Add", BindingFlags.InvokeMethod, null, objBooks, null);
object objSheets = objBook.GetType().InvokeMember("Worksheets", BindingFlags.GetProperty, null, objBook, null);
object objSheet = objSheets.GetType().InvokeMember("Item", BindingFlags.GetProperty, null, objSheets, new object[]{1}, null);
Pascal Beer14y ago
Cool - thanks Vulpes - that is the solution!
Have a nice day
Pascal
Pascal Beer14y ago
and how can I convert it into workbook without cast?
Jignesh Trivedi14y ago
hi,

I thing objBook is object type so you can not get property. try to convert it in to workbook.

hope this help.
Pascal Beer14y ago
Hi
Thanks for your reply. No also "WorkSheet" doesn't work.
If I set the Reference to the Microsofts Office Interop and then I cast the objBook and call:
objSheets = ((Workbook)objBook).Worksheets;
this works fine. But with Reflection not. Is this not a property? The strange thing is, that
objBooks.GetType().GetProperties()

returns an empty list!?

Regards
Pascal
Jignesh Trivedi14y ago
hi pascal,

I thing it is problem with name of the Property.
make sure name of the property is same as object.

I think Property is wrong in you case try with "WorkSheet"

hope this help.