Cannot create a generic method: “T” not found

问题:

I am trying to implement a method that returns a generic list (List), but I keep getting this error message:

The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?)

This is my method code:

public static List<T> doQuery(string query)
{
    SQLiteCommand com = new SQLiteCommand(query, SQLiteManager.connection);
    SQLiteDataReader reader = com.ExecuteReader(CommandBehavior.Default);
    while (reader.Read())
    {
        //other code
    }
}

Why is T not recognized as a generic Type in this situation?

回答1:

You need to tell what is "T" to the method, right now your method does not know what T is. T is known at compile time, the language does not figure out the type on the spot.

Here's an example: static List<T> GetInitializedList<T>(T value, int count)

Reference here: http://www.dotnetperls.com/generic-method