AlertDialog crashes app

Question

my application just crashes whenever it tries to run the alertdialog. I'm not to sure the proper way to do these but what I am doing is, creating a Java Class called 'AboutActivity' which contains the method 'popup()' ideally to create the AlertDialog. In my main activity I am creating the object and calling the method.

'popup()' in AboutActivity:

public class AboutActivity extends DialogFragment
{
    public void popup()
    {
        new AlertDialog.Builder(getActivity())
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setTitle("About Us")
                .setMessage("Blah Blah Blah")
                .setCancelable(true)
                .setPositiveButton("Ok", null)
                .show();
    }
}

Main activity:

 public boolean onOptionsItemSelected(MenuItem item) {
        switch(item.getItemId()){
            case R.id.nav_About:{
                AboutActivity about = new AboutActivity();
                about.popup();
            }
}

Also `AboutActivity` is actually a Fragment, so please try to follow naming convention — OneCricketeer, Apr 13 '17 at 01:00
http://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this — OneCricketeer, Apr 13 '17 at 03:05

score 0 · Answer 1 · answered Apr 13 '17 at 01:02

0

Main activity:

Just create the dialog there... There is no point in having a Fragment just to load that

 new AlertDialog.Builder(MainActivity.this)
            .setIcon(android.R.drawable.ic_dialog_alert)
            .setTitle("About Us")
            .setMessage("Blah Blah Blah")
            .setCancelable(true)
            .setPositiveButton("Ok", null)
            .show();

Your problem is that getActivity() is unassigned for a brand new, unattached Fragment

answered Apr 13 '17 at 01:02

OneCricketeer

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My teacher specifically asks, "Implement the dialog box with "AboutActivity". – Andrew Ricci Apr 13 '17 at 01:05
But "AboutActivity" is not an Activity, so I think you may have followed some other instructions wrong – OneCricketeer Apr 13 '17 at 03:04

Kia · Accepted Answer · 2017-04-13T01:17:10.393

0

Send a logcat, but I guess it's because your getActivity() is null. If you want to have it inside your method just pass your activity there.

'popup()' in AboutActivity:

public class AboutActivity extends DialogFragment {
  public void popup(Activity activity) {
    new AlertDialog.Builder(activity)
    .setIcon(android.R.drawable.ic_dialog_alert)
    .setTitle("About Us")
    .setMessage("Blah Blah Blah")
    .setCancelable(true)
    .setPositiveButton("Ok", null)
    .show();
  }
}

Main activity:

public boolean onOptionsItemSelected(MenuItem item) {
  switch(item.getItemId()){
    case R.id.nav_About:{
      AboutActivity about = new AboutActivity();
      about.popup(this);
  }
}

edited Apr 13 '17 at 01:17

answered Apr 13 '17 at 01:07

Kia

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This worked for me thanks, but in your version of 'Main activity' the 'this' should be in the 'about.popup()' – Andrew Ricci Apr 13 '17 at 01:14
Yes, you are right, it should be passed there. Edited it. – Kia Apr 13 '17 at 01:17

score 0 · Answer 3 · answered Apr 13 '17 at 01:08

First of all replace your alert dialog code with this:

new AlertDialog.Builder(AboutActivity.this)
            .setIcon(android.R.drawable.ic_dialog_alert)
            .setTitle("About Us")
            .setMessage("Blah Blah Blah")
            .setCancelable(true)
            .setPositiveButton("Ok", null)
            .show();

This always works for me and I think your problem may be that you are using getActivity() which might not be the context, so use AboutActivity.this like I did in the example above.

Second, if I am correct, you are trying to go to the AboutActivity from the MainActivity, so you need to use an intent.

Replace this:

AboutActivity about = new AboutActivity();
about.popup();

with this:

Intent intent = new Intent(getApplicationContext(), AboutActivity.class);
startActivity(intent);

If you replace you code with these two, you should be good to go!

Hope this helps!

AlertDialog crashes app

3 Answers3