How to define a global variable in ASP.net web app

Question

I have face a requirement,

I want client access a data center but without use database , so I want my web app can retain a global or Application session variable, that contains the data, every client can access the same data... I am try to declare in golabl, but seem it only can store String but others ...

how to solve this problem ?

thanks.

Answer 1

Another option of defining a global variable is by creating a static class with a static property:

public static class GlobalVariables
{
    public static string MyGlobalVariable { get; set; }
}

You can make this more complex if you are going to use this as a data store, but the same idea goes. Say, you have a dictionary to store your global data, you could do something like this:

public static class GlobalData
{
    private static readonly object _syncRoot = new object();
    private static Dictionary<string, int> _data;

    public static int GetItemsByTag(string tag)
    {
        lock (_syncRoot)
        {
            if (_data == null)
                _data = LoadItemsByTag();

            return _data[tag];
        }
    }

    private static Dictionary<string, int> LoadItemsByTag()
    {
        var result = new Dictionary<string, int>();

        // Load the data from e.g. an XML file into the result object.

        return result;
    }
}

Answer 2

To Share the data with all application users, you can use ASP.NET Application object. Given is the sample code to access Application object in ASP.NET:

Hashtable htblGlobalValues = null;

if (Application["GlobalValueKey"] != null)
{
    htblGlobalValues = Application["GlobalValueKey"] as Hashtable;
}
else
{
    htblGlobalValues = new Hashtable();
}

htblGlobalValues.Add("Key1", "Value1");
htblGlobalValues.Add("Key2", "Value2");

this.Application["GlobalValueKey"] = htblGlobalValues;

Application["GlobalValueKey"] can be used anywhere in the whole application by any user. It will be common to all application users.