Thread: I'm trying to open a "FileOpenDialog"

ok, well you are saying this.openFileButton. I believe your problem is you are misinterpretting what this is referencing to. The keyword this references to the class that contains the keyword. So, when you have a nested class (such as the one I assume you have above), this is referring to the nested class, not the outer class.

Look at the code below:

public class OuterClass
{	
	int var = 0;
 
	public OuterClass()
	{
		System.out.println(this.var); //References OuterClass's var variable
	}
	public class InnerClass
	{
		int var = 0;
 
		public InnerClass()
		{
			System.out.println(this.var); //References InnerClass's var variable
		}
		public class InnerInnerClass
		{
			int var = 0;
 
			public InnerInnerClass()
			{
				System.out.println(this.var); //References InnerInnerClass's var variable
			}
		}
	}
}

Now, if you wanted to reference OuterClass's var variable from inside the InnerClass (by using the keyword this), you would have to say:

public class OuterClass
{	
	int var = 0;
 
	public OuterClass()
	{
		System.out.println(this.var); //References OuterClass's var variable
	}
	public class InnerClass
	{
		int var = 0;
 
		public InnerClass()
		{
			System.out.println(OuterClass.this.var); //References OuterClass's var variable
		}
	}
}

Does that make sense? And could that be your problem?