Solution2.Create Method

void Create(
	string Destination,
	string Name
)

using System.Windows.Forms;
public void OnConnection(object application,
 Extensibility.ext_ConnectMode connectMode, object addInInst,
 ref System.Array custom)
{
    _applicationObject = (DTE2)application;
    _addInInstance = (AddIn)addInInst;
    // Pass the applicationObject member variable to the code example.
    CreateExample((DTE2)_applicationObject);
}
public void CreateExample(DTE2 dte)
{
    // This add-in creates a solution.
    try
    {
        Solution2 soln = (Solution2)_applicationObject.Solution;
        MessageBox.Show("Creating a  solution ");
        // Make sure that the file path below exists on your computer.
        // You can modify the path.
        soln.Create("c:\temp2", "ANewSoln2.sln");
    }
    catch(SystemException ex)
    {
    MessageBox.Show("ERROR: " + ex);
    }
}