How can I resolve “Item has already been added. Key in dictionary:” errors?

Question

I have an application which got hung up when I tried to add items to it. When I checked the trace file I got this entry:

   for (int i=0; i

        

Answer 1

The problem is that in a sorted list each key needs to be unique. So you need to check that you aren't inserting the same key (guid value) twice. Code shown below:

 for (int i=0; i

This will ensure that each key is unique. If however you are expecting more than one value for each key then you need to use a different type of collection.