Question

I am trying to fill out a pdf form using reflection as below:

// Get the form fields for this PDF and fill them in!
 var formFieldMap = GetFormFieldNames(pdfTemplate);

     foreach (var fields in formFieldMap)
       {
         var fieldName = UppercaseFirst(fields.Key.Replace("pdf_", ""));

         var proPertyValue = fosques.GetType().GetProperty(fieldName).GetValue(ques, null);

          formFieldMap[fields.Key] = proPertyValue.ToString();

         }

This works fine for first property, but on second iteration it say Collection was modified; enumeration operation may not execute.

Should I create another collection of fields, or can I avoid this?

Answer 1

You are referencing the list you are enumerating through inside the enumeration.

You don’t need to get formFieldMapy[fields.Key] because you already have access to it, so you could simply do:

foreach (var fields in formFieldMap)
{
  var fieldName = UppercaseFirst(fields.Key.Replace("pdf_", ""));

  var proPertyValue = fosques.GetType().GetProperty(fieldName).GetValue(ques, null);
  fields.Value = proPertyValue.ToString();
  //formFieldMap[fields.Key] = proPertyValue.ToString();
 }

The above does the same thing, it just doesn’t directly modify what you are enumerating.