Crash when adding a button to a panel view

I have 开发者_JS百科the following code that shows a panel. It displays a button on the panel but as soon as I assign a Click Handler to it the app crashes!

It crashes on the line .setOnClickListener

Button button =  (Button)findViewById(R.id.buttonclick);
button.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                  hide();

                }
              });

LogCat shows... 09-22 14:54:09.953: ERROR/Error(7786): java.lang.NullPointerException 09-22 14:54:09.953: ERROR/Error(7786): at com.pinkfroot.leefinder.leeFinderMain$PopupPanel.(leeFinderMain.java:598)

Adding a breakpoint further down shows that R.id.buttonclick has an id but button is null.

From your error it sounds as if the Button returned by findViewById is coming back as a null reference. In which case your problem will be somewhere within findViewById (or the parameter passed to it).

At which point do you have setContentView(R.layout.main);. This code has to be invoked before you can access your button via Button button = (Button)findViewById(R.id.buttonclick);