Running into a run-time error

[Naziru Gelajo]

Greetings everyone, everything compiles just fine. The issue I'm having is that I'm getting a runtime error with my code. The error I'm getting is in regards to a NULL pointer exception that states the following:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at com.Gelajo.africancurrencyconverter.MainActivity.onCreate(MainActivity.java:41)

I have checked the code and I don't understand why I'm getting a nullpointerexception. the issue is with this code here at line 41:

btnNaira.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dollarToNaira();
            }
        });

This is the method being called. Thanks:

public void dollarToNaira() {

        try {
            dollarAmt = txtAmount.getText().toString();
            nairaAmt = (Double.parseDouble(dollarAmt) * 199.00);
            lblOutput.setText(dollarAmt + "U.S. Dollars = " + nairaAmt + " Nigerian Naira.");
        }catch(Exception ex) {
            message = "Please enter a valid numerical amount";
            lblOutput.setText(message);
        }finally {
            txtAmount.requestFocus();
            txtAmount.selectAll();
        }
    }

[Paul Clapham]

A NullPointerException on that line means that the variable "btnNaira" is null. So you should review your code to find out why that is the case.

[Naziru Gelajo]

Paul Clapham wrote:A NullPointerException on that line means that the variable "btnNaira" is null. So you should review your code to find out why that is the case.

Thanks will do sir.