Desktop Application C# Global variable

Desktop app

C#

Compact Framework

2 projects in one solution

Main project uses DataAccess project (reference), because everything related to Database is in DataAcess project I am actually connecting to 2 different databases.

How can I make a "global" variable that would be available from both projects? (without needing to add reference - which, I cannot do, because it would be circular ref)

In web I had (dataaccess part):

 string strConnRSS = System.Configuration.ConfigurationManager.AppSettings["something1"];
 string strConnRSS = System.Configuration.ConfigurationManager.AppSettings["something2"];

getting data from the web.config (this was in the web prj):

 <appSettings>
 <add key="something1" value="server=...;database=...;uid=...;password=...;" />
 <add key="something2" value="server=...;database=...;uid=...;password=...;" />
 </appSettings>

is there something similar in a desktop app?

thanks

Update: http://www.egg开发者_运维百科headcafe.com/articles/dotnetcompactframework_app_config.asp this looks helpful, but we have a settings page, where you can change the actual connection string

Create a 3rd library, with common code for both your projects like this and add references to it.

public static class GlobalVariables
{
    public static string SomeCommonVar { get { // read this lib app.config } }
}

Not sure I would like to use this approach. I would always think long and hard before I decide to have a global variable like this, perhaps there is some better design/architecture which would allow you to work around this? Anyway, you did not state which .Net version you are targeting but here is a code sample for 3.5.

In my exe:

private void button1_Click(object sender, EventArgs e)
{
    ConfigurationManager.AppSettings.Set("TestData", "TestValue");

    string testData = ClassLibrary1.Class1.GetTestData();
    if (testData != null )
        MessageBox.Show(testData);
    else
        MessageBox.Show("Not found");
}

In my class library:

public class Class1
{
    public static string GetTestData()
    {
        return ConfigurationSettings.AppSettings["TestData"];
    }
}

The exe obviously have a reference to the class library.