Android - AlertDialog.Builder crashes when launching it a second time

Question

I am opening an AlertDialog to present the user a text input in order to name a new item. This works fine the first time it opens. But the second time I click the button that launches the dialog, the app crashes. I get this error:

12-02 16:01:04.205: E/AndroidRuntime(515): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

I'm not sure what this means or where I would call this removeView() .

Here is my code:

public class ShoppingList extends Activity implements OnClickListener{

        private AlertDialog.Builder m_alert;
        private Context m_context;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.shopping_list);
            m_context = getApplicationContext();
            LayoutInflater inflater = (LayoutInflater) m_context.getSystemService(LAYOUT_INFLATER_SERVICE);
            View layout = inflater.inflate(R.layout.add_shopping_list, (ViewGroup) findViewById(R.id.layout_root));
            m_alert = new AlertDialog.Builder(ShoppingList.this);
            //final EditText input = new EditText(this);
            //m_alert.setView(input);
            m_alert.setView(layout);
            final EditText input = (EditText)layout.findViewById(R.id.new_sl_name);
            m_alert.setPositiveButton(R.string.add_button, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    String value = input.getText().toString().trim();
                    Toast.makeText(m_context, value,
                            Toast.LENGTH_SHORT).show();
                    m_alert.create();
                }
            });

            m_alert.setNegativeButton(R.string.cancel_button,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        dialog.cancel();
                        m_alert.create();
                    }
                }
            );

            // Add Button. . .
            Button addButton = (Button)findViewById(R.id.add_sl_button);
            addButton.setOnClickListener(this);
        }

        public void onClick(View v) {
            if(!this.isFinishing())
                m_alert.show();
        }
    }

Answer 1

This is most likely because you are using m_alert.create(); in a wrong place.

Check this tutorial on dialogs: Dialogs .

Answer 2

m_alert.create() is called after clicking on the positive and negative buttons. What this does, is create the dialog again.

Use m_alert.dismiss() instead, so your dialog is dismissed, and you can use it again later

Answer 3

您可以在活动中覆盖onCreateDialog（）以创建对话框，这将帮助您在此处查看有关对话框的详细信息

Answer 4

This might help someone. I build most of my apps on my laptop. I just got my office put back together and got my pc fired up. When I tried to load my projects from my cloud storage on my pc it seemed like there were a few build errors that happened. For AlertDialog.Builder Crash I notice that my pc on a fresh Android Studio install set my "import" to android.support.v7.app.AlertDialog instead of android.app.AlertDialog for some reason. I deleted the import and re selected the android.app.AlertDialog and everything worked like normal. I don't know if this is a bug or just how Android Studio installs files as a default. For similar errors might be worth while deleting all the import files and re selecting the ones you know apply. Good Luck!