Using a generic type System.Collections.Generic.KeyValuePair requires 2 type parameters

C # when preparing to use System.Collections.Generic.KeyValuePair traversal hashtable, the code prompts for an error:

This is actually a very simple error, in Eclipse in the tool pop-up prompt solution, click the mouse to solve the problem, Visual Studio 2010 is not.

But the hint is more clear, you need to specify the type of two parameters.
It can be specified based on the data type of the key and value stored in your hashtable.
For example:

KeyValuePair<stringint>KeyValuePair<intint>KeyValuePair<intlong>

Wait, mainly look at the data type of key and value stored in your Hashtable, the first parameter corresponds to key, the second parameter corresponds to value.

Using a generic type System.Collections.Generic.KeyValuePair requires 2 type parameters