Question

I have been trying to pass a string value from one method into another. Here are my two methods.

Method 1-

public void listBox1_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
    if (e.AddedItems.Count > 0)
    {
        var c_id = (e.AddedItems[0] as Foodlist).C_ID;
        string listboxid = c_id.ToString();
    }
}

I want the string listboxid value in my second method so that I can use it for comparison.
Method 2-

public void deletemyfood()
{
    using (FoodDataContext context = new FoodDataContext(Con_String))
    {
        string listboxindex = listboxid;
        IQueryable<FoodViewModel> foodQuery = from c in context.FoodTable where c.C_ID.ToString() == listboxindex select c;
        ....
    }
}

any ideas or suggestions?

Answer 1

Here’s a Simple example on how you can use return values and parameters:

class Program
{
    static void Main(string[] args)
    {
        var result = Method1("Test");
    }

   static string Method1(string input)
   {
       return string.Format("I got this input: {0}", input);
   }
}

In this example, the method Method1 takes a string parameter and then returns a string.

In your case you might want to change the method signature of DeleteMyFood to this:

public void DeleteMyFood(string foodId)

If you want some sort of result though, too know when the method succeeded or not, you might want to have a value returned from the method as well. This can be done by modifying the method signature once again:

public bool DeleteMyFood(string foodId)

If I understand correctly based on your comments, you want to change the event handler to this:

public void listBox1_SelectionChanged(object sender,
                                    System.Windows.Controls.SelectionChangedEventArgs e)
{
    if (e.AddedItems.Count > 0)
    {
        var c_id = (e.AddedItems[0] as Foodlist).C_ID;
        string listboxid = c_id.ToString();
        DeleteMyFood(listboxid);
    }
}

This requires that the method DeleteMyFood accepts a parameter of type string, so we need to change that as well:

public void deletemyfood(string foodId)
{
    using (FoodDataContext context = new FoodDataContext(Con_String))
    {
        string listboxindex = listboxid;
        IQueryable<FoodViewModel> foodQuery = from c in context.FoodTable where c.C_ID.ToString() == foodId select c;
        // .. rest of code here ..
    }
}