CODEWITHSUNDEEP
javaandroidandroid-activitynullpointerexceptiondialog
user5627680
user5627680

Reputation:

ANDROID: launch new activity from inflated pop up view

I have a main_activity in which by pressing a button I launch a form to be completed:

popup= getLayoutInflater().inflate(R.layout.pop_up, null);
    signup = new SignUp(popup);
    register = (Button) findViewById(R.id.sign_up);
    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(MyLocalBartender.this);
    alertBuilder.setView(popup);
    final AlertDialog dialog = alertBuilder.create();
    register.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            dialog.dismiss();
            dialog.show();
        }
    });

By what you can see I'm using a second activity class (SignUp) to manage the form and not the root class from which it was launched (main_activity). In this new class I set all the click listeners etc to verify the inputs through a third class that implements an OnClickListener.

Everything works fine until this point. But now I want to test the page/activity called HomePage in which the user should land to if the form is filled. So what I don know is I remove the click listener from the previous handler and I create an anonymous one to simply open the new activity on register button pressed:

 //       signup_registerButton.setOnClickListener(new SignupListener(signup_emailField,signup_passwordField1,
 //               signup_passwordField2, signup_textTemp,signup_organiserRadio, signup_staffRadio,signup_alertMessage));
    ////*************************TEST******************* START
    signup_registerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent menu = new Intent(getApplicationContext(), HomePage.class);
            startActivity(menu);
        }
    });

    ////*************************TEST******************* END

but this returns a NullPointerException. I've tried to launch the HomePage.class from the main_activity directly and it works and also I've tried to launch the main activity from this REGISTER button, which didn't work, so this tells me that the problem it is somewhere here.

Upvotes: 1

Views: 327

Answers (1)

Cedric Franck
Cedric Franck

Reputation: 526

You need to pass an Activity Context to the Intent constructor. Activities context and Applications context are not the same. Activities context hold much more inforamtions.

In your case you can do like this:

signup_registerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent menu = new Intent(yourActivity, HomePage.class);
            startActivity(menu);
        }
    });

where yourActivity is your activity instance. You can pass it as variable or access it via main_activity.this from inner classes (Listeners) on anywhere inside your class.

Upvotes: 1

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