I've run into a couple of problems working with QAxObjects:
1) I can't figure out how to access the 'member constants' of a QAxObject. I've dumped out (specifically accessing Excel). I've run the generateDocumentation() on my QAxObject, and I can see all the constants and their values, however I'm not sure how to actually query their value at run-time (in case they differ from version to version of excel say). Below are a few methods I've tried:
Qt Code: 
  1. QAxObject *excel = new QAxObject("Excel.Application",0);
  2. //attempt 1
  3. int num = excel->property("xlAll").toInt(); //from documentation, should have value of -4104
  4. //attempt 2
  5. int num = excel->querySubObject("xlAll").asVariant().toInt()
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2) How do you pass an ignored value to a function when calling '->querySubObject()'? Some functions will have optional parameters, but will expect a void value for any parameters you wish to ignore. A specific example is below:
For excel, if you want to add a worksheet to the end of the list of sheets, you call 'add(QVariant before, QVariant after)', where the before should be null if you want to use the 'after'. Apparently in C# you would use a value of 'Type.Missing', however I can not find the equivalent with QVariant.

Thanks.