How do I add a value in a hash table to a string list? (C#)

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I have a hashtable which is containing my tcpUsers, and i want to output this to a string list as an easy way to manage currently connect users. How would I do this. Any other easier method?

What I have tried:

I'm not sure where to start, but i want to just add a value onto the list, maybe into the next available index?

Posted 20-Dec-16 13:40pm

Member 12706516

Updated 22-Dec-16 9:15am

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Philippe Mori 20-Dec-16 21:00pm

If you have a hash table, it was probably done for performance purpose of supporting a lot of users with minimal overhead. So it probably does not make much sense to use a list instead. You probably cannot simply add user at the end since you probably have to ensure that the user is not already in the table. And you don't need a list to iterate over existing values. Also, where is your code?

Ramza360 22-Dec-16 14:46pm

If your trying to display the data to the user, just cast the hash table using a LINQ statement and set the data source property. In fact using this method you can allow a privileged user to edit the value, which upon edit submit, you must update the hash table entry.

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Ramza360 · Answer 1 · 2016-12-22T09:15:00

If you need to display this information to some users then it would be best to cast and set a DataSource property of a useful control. In the example i used a data grid view since this is usually right for displaying table data.

Example for displaying:

C#

class Person {
     public string FirstName { get; set; }
     public string LastName { get; set; }
     public int Age { get; set; }
     public bool Current { get; set; }
}

HashTable table = new HashTable();
table["4874"] = new Person() {
   FirstName = "Berny",
   LastName = "Sanders",
   Age = 65,
   Current = true
};

table["6451"] = new Person() {
   FirstName = "Michelle",
   LastName = "Obama",
   Age = 50,
   Current = false
};

// The below assumes your using a data grid view with four columns, having the DataPropertyNames set to the same name as the Column name. If they are different, a new column will be added for each DataPropertyName not set.
dataGridView1.DataSource = table.Cast<DictionaryEntry>().Select(x => new {
    Column1_FirstName = ((Person)x.Value).FirstName,
    Column2_LastName = ((Person)x.Value).LastName,
    Column3_Age = ((Person)x.Value).Age,
    Column4_Current = ((Person)x.Value).Current
}).Reverse().ToList();

OUTPUT::

FirstName | LastName | Age | Current
Berny     | Sanders  | 65  |  True
Michelle  |  Obama   | 50  |  False

Note the use of Reverse().  Calling ToList() on a cast of the Hashtable will read from bottom up, so to keep the order (though the order is not guaranteed), call reverse().