Question

I’ve got two different forms in my WinForms app (MainForm and Form2 say). They both ask for an access of MyDataSet, via a “getInstance” static method. The issue is after MainForm has got an instance, when Form2 needs to get an instance the static “myDataSet” variable is null, whereas I expect to have been already set? Any ideas?

public class MyDataSet
{
    public static MyDataSet myDataSet;   
       // This was null 2nd call to getInstance

    private DataSet myData = new DataSet();

    public static MyDataSet GetInstance()
    {
        if (myDataSet == null)
        {
            return new MyDataSet();
        }
        else
        {
            return myDataSet;
        }
    }

So it almost seems the static “myDataSet” variable isn’t working in terms of only having once instance?

Answer 1

you forgot to assign the newly create instance to myDataset

if(myDataSet == null)
{
    myDataSet = new MyDataSet();
}
return myDataSet