NullPointerException's on StartActivityForResult, Struggling with SQLite in android i think?

I have one class called Budget.java, within that i start Keypad.java. This was all working fine up until recently when i added a bunch of code to Keypad.java (The added code was to update a row in my SQLite database on the press of a button, all the unrelated methods were working until i tried to implement this). Now using breakpoints i think i've figured out that i get the error message as soon as i try to open the Keypad activity and i don't have a clue what could be the problem.

Maybe it's my misunderstanding of the sqlite open helper? Or perhaps its because i'm 开发者_Python百科using StartActivityForResult?

Any suggestions would be very appreciated! I can upload the logcat if you think that would help. I uploaded the two little classes to pastebin, you might find it easier to read?

Budget.java ( look for ListItemCommonIntent )

keypad.java

In your Keypad.java, you have the following outside the onCreate:

 EditText userAmount=(EditText)this.findViewById(R.id.cost_input);

This wont work because you have to use the setContentView to reference the layout where you want to find the view. And when it initializes userAmount, the object is not available yet (so this is null) .

Try this:

private EditText userAmount;

protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.keypad);
    userAmount=(EditText)findViewById(R.id.cost_input);
    MySpinner();
    Main();
}