Question

I am pretty new to android app development and java and I encountered the following error when trying to call a method from another class:

Cannot make a static reference to the non-static method showToast(String) from the type LoginActivity

The reason I want to call this in the other class and not instantiate it in the class itself is because of adaptability and upgradeability issues. This seems a fine concept by me or is it something that is way overrated?

The relevant code is:

CreateAccountActivity

public class NewAccountActivity extends Activity{

private Button mCreateAccountButton;

 @Override
 public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.newaccount);

    mCreateAccountButton = (Button) findViewById(R.id.createaccount_button);

    registerButtonListeners();

    }

    private void registerButtonListeners() {
        mCreateAccountButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                LoginActivity.showToast(getString(R.string.createaccount_message));
            }
        });
    }   
}

LoginActivity

public void showToast(String toastString) {
    LayoutInflater inflater = getLayoutInflater();
    View layout = inflater.inflate(R.layout.toast_layout, (ViewGroup) findViewById(R.id.toast_layout_root));

    ImageView image = (ImageView) layout.findViewById(R.id.toastImage);
    image.setImageResource(R.drawable.android);

    TextView text = (TextView) layout.findViewById(R.id.toastText);
    text.setText(toastString);

    Toast toast = new Toast(getApplicationContext());
    toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
    toast.setDuration(Toast.LENGTH_SHORT);
    toast.setView(layout);
    toast.show(); 
}

Creating a new LoginActivity object and then calling showToast on it makes the error messages go away but gives me a NullPointerException instead.

Answer 1

if you want to call showToast in the static way you have to make the method showToast static.

public static void showToast(...)

Edit: where do you get the NullPointerException?