Question

Basically I have 2 classes, “Manifest” and “BrowserAction”, set out like this:

public class BrowserAction
{
    public string default_icon {get; set;}
    public string default_title {get; set;}
    public string default_popup {get; set;}
}


public class Manifest
{
    public BrowserAction browser_action {get; set;}
}

The problem is, that when I try to set an instance of the Manifest class’ browser_action.default_popup, like this:

public void setManifest()
{
    Manifest newManifest = new Manifest();
    newManifest.browser_action.default_popup = "popup.html";
}

I get a System.NullReferenceException. I’ve looked around but I can’t seem to find what the problem is. It works fine for other properties of the “Manifest” class that are just strings etc.

If it’s relevant, my IDE is MonoDevelop 2.4, with Mono 2.6.7 for my framework.

Answer 1

You’ll have to intialize browser_action too before accessing properties on that instance.

newManifest.browser_action= new BrowserAction();