нажатие кнопки для перехода на другой экран - вылетает - PullRequest
0 голосов
/ 08 сентября 2018

на главном экране активности у меня есть кнопка, которая переводит меня на другой экран.но когда я нажимаю, что мое приложение падает, и я получаю сообщение об ошибке.

java.lang.RuntimeException: не удается запустить действие ComponentInfo {com.app.appname / com.app.appname.view}:java.lang.NullPointerException

Синее подчеркивание находится на view.java в этой строке:

ArrayList spinnerArrayList = bundle.getIntegerArrayList ("arraylist");

Вот мой полный код view.java:

public class view extends AppCompatActivity {


    private LinearLayout mLinearLayout;
    private ArrayList<SearchableSpinner> mSpinners;
    private List<AppCompatButton> mButtons = new ArrayList<>();
    private List<CheckBox> mCheckboxes = new ArrayList<>();
    private List<TextView> mTextviews = new ArrayList<>();
    private List<EditText> mEdittexts = new ArrayList<>();
    private List<View> mViews = new ArrayList<>();
    private Map<String, String> numberItemValues = new HashMap<>();
    List<String> itemList = new ArrayList<>();
    private Spinner spinner;
    private TextView textview;
    private CheckBox checkbox;





    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_create);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        GlobalClass globalClass = (GlobalClass) this.getApplicationContext();
        textview = findViewById(R.id.textview);
        checkbox = findViewById(R.id.checkbox);
        ArrayList<String> items = new ArrayList<>();
        items.add(String.valueOf(mSpinners)); // add you selected item
        globalClass.setItems(items);
        mSpinners = new ArrayList<>();
        mLinearLayout = findViewById(R.id.my_linearLayout);
        findViewById(R.id.my_linearLayout).requestFocus();







        Intent gotIntent = getIntent();
        Bundle bundle = getIntent().getBundleExtra("extraBundle");

        ArrayList<Integer> spinnerArrayList = bundle.getIntegerArrayList("arraylist");


        //creating a for loop, to create the number of spinners in the spinnerarray list size
        for(int i = 0; i < spinnerArrayList.size(); i++) {
            final Spinner spinner = makeSpinner();
            mLinearLayout.addView(spinner);

            final View newView = makeView();
            //Add a new view
            mLinearLayout.addView(newView);
            mViews.add(newView);


            final EditText newEdittext = makeEdittext();
            mLinearLayout.addView(newEdittext);
            mEdittexts.add(newEdittext);


            final CheckBox newCheckbox = makeCheckbox();
            mLinearLayout.addView(newCheckbox);

            //TODO add checkbox to your list
            mCheckboxes.add(newCheckbox);


            final TextView newTextview = makeTextview();
            mLinearLayout.addView(newTextview);
            mTextviews.add(newTextview);




            newCheckbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    // makes the set disappear when checkbox is ticked.

                    newCheckbox.setVisibility(View.VISIBLE);
                    spinner.setVisibility(View.VISIBLE);
                    newView.setVisibility(View.VISIBLE);
                    newEdittext.setVisibility(View.VISIBLE);
                    newTextview.setVisibility(View.VISIBLE);
                    //textview.setVisibility(View.VISIBLE);

                    newCheckbox.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            newCheckbox.setVisibility(View.GONE);
                        }
                    });



                    spinner.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            spinner.setVisibility(View.GONE);
                        }
                    });

                    newView.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            newView.setVisibility(View.GONE);
                        }
                    });

                    newEdittext.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            newEdittext.setVisibility(View.GONE);
                        }
                    });

                    newTextview.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            newTextview.setVisibility(View.GONE);
                        }
                    });




                }
            });








            //TODO Add the spinner on item selected listener to get selected items
            spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                @Override
                public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
                    String currentItem = itemList.get(position);
                    String aisleNumber = numberItemValues.get(currentItem);
                    //TODO you can use the above aisle number to add to your text view
                    //mTextviews.get(mTextviews.size() -1).setText(aisleNumber);
                    newTextview.setText(aisleNumber);
                }

                @Override
                public void onNothingSelected(AdapterView<?> parentView) {
                    //  code here
                }
            });


            final int listSize = mViews.size();

            //code for deleting the said item.
            newView.setOnClickListener(new View.OnClickListener() {
                //start
                @Override
                public void onClick(View view) {

                    //when the 'new button' is pressed, alert shows if you are sure you want to delete the item or not.

                    final View.OnClickListener context = this;


                    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(view.this);


                    // set title
                    alertDialogBuilder.setTitle("Delete Item");

                    // set dialog message
                    alertDialogBuilder
                            .setMessage("Are you sure you want to delete this item?")
                            .setCancelable(false)
                            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    // if this button is clicked, close
                                    // current activity


                                    if (listSize > 0) {

                                        mCheckboxes.get(listSize - 1).setVisibility(View.GONE);
                                        mSpinners.get(listSize - 1).setVisibility(View.GONE);
                                        mViews.get(listSize - 1).setVisibility(View.GONE);
                                        mTextviews.get(listSize - 1).setVisibility(View.GONE);
                                        mEdittexts.get(listSize - 1).setVisibility(View.GONE);
                                        Toast.makeText(getBaseContext(), "Item removed.", Toast.LENGTH_SHORT).show();

                                    }


                                }
                            })
                            .setNegativeButton("No", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    // if this button is clicked, just close
                                    // the dialog box and do nothing
                                    dialog.cancel();
                                }
                            });

                    // create alert dialog
                    AlertDialog alertDialog = alertDialogBuilder.create();

                    // show it
                    alertDialog.show();


                }
            });






            //setting spinner selection values
            int positionOfSpinner = spinnerArrayList.get(i);
            spinner.setSelection(positionOfSpinner);




        }









            //code for the add button to add more items
        FloatingActionButton floatingActionButton =
                (FloatingActionButton) findViewById(R.id.fab);



        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getBaseContext(), "Item added!", Toast.LENGTH_SHORT).show();
                spinner = findViewById(R.id.spinner);
                mLinearLayout.setVisibility(View.VISIBLE);




                // Handle ze click.
                final Spinner spinner = makeSpinner();
                mLinearLayout.addView(spinner);



                LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) spinner.getLayoutParams();
                layoutParams.setMargins(5, 100, 10, 0); //top 70

                Resources resources = getResources();
                DisplayMetrics metrics = resources.getDisplayMetrics();

                layoutParams.height = (int) (70 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //80
                layoutParams.width = (int) (240 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)); //240
                spinner.setLayoutParams(layoutParams);

                final View newView = makeView();
                //Add a new view
                mLinearLayout.addView(newView);
                mViews.add(newView);


                final EditText newEdittext = makeEdittext();
                mLinearLayout.addView(newEdittext);
                mEdittexts.add(newEdittext);


                final int listSize = mViews.size();


                //code for deleting the said item.
                //code for deleting the said item.
                newView.setOnClickListener(new View.OnClickListener() {
                    //start
                    @Override
                    public void onClick(View view) {

                        //when the 'new button' is pressed, alert shows if you are sure you want to delete the item or not.

                        final View.OnClickListener context = this;


                        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(view.this);


                        // set title
                        alertDialogBuilder.setTitle("Delete Item");

                        // set dialog message
                        alertDialogBuilder
                                .setMessage("Are you sure you want to delete this item?")
                                .setCancelable(false)
                                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog, int id) {
                                        // if this button is clicked, close
                                        // current activity
                                        //final int listSize = mViews.size();


                                        if (listSize > 0) {

                                            mCheckboxes.get(listSize - 1).setVisibility(View.GONE);
                                            mSpinners.get(listSize - 1).setVisibility(View.GONE);
                                            mViews.get(listSize - 1).setVisibility(View.GONE);
                                            mTextviews.get(listSize - 1).setVisibility(View.GONE);
                                            mEdittexts.get(listSize - 1).setVisibility(View.GONE);
                                            Toast.makeText(getBaseContext(), "Item removed.", Toast.LENGTH_SHORT).show();

                                        }


                                    }
                                })
                                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog, int id) {
                                        // if this button is clicked, just close
                                        // the dialog box and do nothing
                                        dialog.cancel();
                                    }
                                });

                        // create alert dialog
                        AlertDialog alertDialog = alertDialogBuilder.create();

                        // show it
                        alertDialog.show();


                    }
                });


                //Add a new checkbox
                final CheckBox newCheckbox = makeCheckbox();
                mLinearLayout.addView(newCheckbox);

                //TODO add checkbox to your list
                mCheckboxes.add(newCheckbox);



                newCheckbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                        // makes the set disappear when checkbox is ticked.

                        newCheckbox.setVisibility(View.VISIBLE);
                        spinner.setVisibility(View.VISIBLE);
                        newView.setVisibility(View.VISIBLE);
                        newEdittext.setVisibility(View.VISIBLE);
                        //textview.setVisibility(View.VISIBLE);

                        newCheckbox.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                            @Override
                            public void onAnimationEnd(Animator animation) {
                                super.onAnimationEnd(animation);
                                newCheckbox.setVisibility(View.GONE);
                            }
                        });



                        spinner.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                            @Override
                            public void onAnimationEnd(Animator animation) {
                                super.onAnimationEnd(animation);
                                spinner.setVisibility(View.GONE);
                            }
                        });

                        newView.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                            @Override
                            public void onAnimationEnd(Animator animation) {
                                super.onAnimationEnd(animation);
                                newView.setVisibility(View.GONE);
                            }
                        });

                        newEdittext.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                            @Override
                            public void onAnimationEnd(Animator animation) {
                                super.onAnimationEnd(animation);
                                newEdittext.setVisibility(View.GONE);
                            }
                        });


                      /*  textview.animate().alpha(0.0f).setDuration(1000).setListener(new AnimatorListenerAdapter() {
                            @Override
                            public void onAnimationEnd(Animator animation) {
                                super.onAnimationEnd(animation);
                                textview.setVisibility(View.GONE);
                            }
                        });*/


                    }
                });






                final TextView newTextview = makeTextview();
                mLinearLayout.addView(newTextview);
                mTextviews.add(newTextview);

                //TODO Add the spinner on item selected listener to get selected items
                spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                    @Override
                    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
                        String currentItem = itemList.get(position);
                        String aisleNumber = numberItemValues.get(currentItem);
                        //TODO you can use the above aisle number to add to your text view
                        //mTextviews.get(mTextviews.size() -1).setText(aisleNumber);
                        newTextview.setText(aisleNumber);
                    }

                    @Override
                    public void onNothingSelected(AdapterView<?> parentView) {
                        //  code here
                    }

                });


            }
        });

    }






    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.create_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();

        if (id == R.id.action_settings) {
            Intent startSettingsActivity = new Intent(this, settings.class);
            startActivity(startSettingsActivity);
            //start the settings activity here.
            return true;
        }


       /* else if (id == R.id.action_delete) {

            for(int j=0; j<mCheckboxes.size(); j++){
                mCheckboxes.get(j).setVisibility(View.GONE);
            }
            for(int j=0; j<mSpinners.size(); j++){
                mSpinners.get(j).setVisibility(View.GONE);
            }
            for(int j=0; j<mViews.size(); j++){
                mViews.get(j).setVisibility(View.GONE);
            }
            for(int j=0; j<mTextviews.size(); j++){
                mTextviews.get(j).setVisibility(View.GONE);
            }
            for(int j=0; j<mEdittexts.size(); j++){
                mEdittexts.get(j).setVisibility(View.GONE);
            }

            Toast.makeText(getBaseContext(), "List removed.", Toast.LENGTH_SHORT).show();

            return true;

        }*/



        else if (id ==R.id.action_help)  {


            // setup the alert builder
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Help");
            builder.setMessage("To use this app, first go to Create your Shopping List.\n" +
                    "Here, you can add items to your list. Once you have added all items, you can click the menu at the top right corner (or if it doesnt appear press your menu button beside your home button on your device, then click View your List.\n" +
                    "This will take you to the screen where you can view you shopping list with the items in aisle order to make your shop much easier.\n" +
                    "You can still add items at this point. Press the white background of each item to delete the item if you wish.");

            // add a button
            builder.setPositiveButton("OK", null);

            // create and show the alert dialog
            AlertDialog dialog = builder.create();
            dialog.show();





            return true;

        }




        return super.onOptionsItemSelected(item);
    }





    //use a relative layout and specify which ones are to layout_toRightOf and layout_below

    //DUPLICATING ITEMS WHEN FAB IS PRESSED//
    private CheckBox makeCheckbox() {
        //Create new Checkbox
        CheckBox checkbox = new CheckBox(this);

        // Setup layout
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);




        //setup relative layout for the positioning of the objects
        Resources resources = getResources();
        DisplayMetrics metrics = resources.getDisplayMetrics();
        RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams((int) (70 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)), (int) (240 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT)));
        relativeParams.addRule(RelativeLayout.RIGHT_OF, R.id.textview);


        checkbox.setLayoutParams(relativeParams);

        // RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(relativeParams.addRule(RelativeLayout.RIGHT_OF, R.id.textview));

        checkbox.setLayoutParams(layoutParams);
        return checkbox;
    }



    private TextView makeTextview() {
        //create new textview
        TextView textview = new TextView(this);

        //setup layout

        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        textview.setLayoutParams(layoutParams);
        textview.setTextSize(30);



        return textview;
    }


    private EditText makeEdittext() {
        //create new edittext
        EditText edittext = new EditText(this);

        //setup layout
        final LinearLayout.LayoutParams lparams = new LinearLayout.LayoutParams(50, 50); // Width , height
        edittext.setLayoutParams(lparams);
        edittext.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_FLAG_DECIMAL | InputType.TYPE_NUMBER_FLAG_SIGNED);
        edittext.setHint("qty");

        return edittext;

    }




    private View makeView() {
        //create new View

        View view = new View(this);
        view.setBackgroundColor(Color.parseColor("#ffffff"));
        LinearLayout.LayoutParams layoutParams =  new LinearLayout.LayoutParams( LinearLayout.LayoutParams.MATCH_PARENT, 100);
        new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, 50);
        //LinearLayout.LayoutParams.MATCH_PARENT,
        // LinearLayout.LayoutParams.WRAP_CONTENT);
        view.setClickable(true);


        view.setLayoutParams(layoutParams);


        //setup layout

        return view;


    }






    private Spinner makeSpinner() {
        //opens csv
        InputStream inputStream = getResources().openRawResource(R.raw.shopitems);
        CSVFile csvFile = new CSVFile(inputStream);
        //TODO I made this variable global, declared it at the very top of this file
        itemList = csvFile.read();

        //Create new spinner
        // SearchableSpinner spinner = (SearchableSpinner) new Spinner(this, Spinner.MODE_DROPDOWN);
        SearchableSpinner spinner = new SearchableSpinner(this);


        // Setup layout
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        spinner.setLayoutParams(layoutParams);
        MyListAdapter adapter = new MyListAdapter(this, R.layout.listrow, R.id.txtid, itemList);


        spinner.setAdapter(adapter);


        //Add it to your list of spinners so you can retrieve their data when you click the getSpinner button
        mSpinners.add(spinner);
        return spinner;
    }



    private class CSVFile {
        InputStream inputStream;

        public CSVFile(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        public List<String> read() {

            List<String> resultList = new ArrayList<String>();
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            try {
                String line;
                while ((line = reader.readLine()) != null) {
                    String[] row = line.split(",");
                    //TODO I edited this part so that you'd add the values in our new hash map variable
                    numberItemValues.put(row[1], row[0]);
                    resultList.add(row[1]);
                }
            } catch (IOException e) {
                Log.e("Main", e.getMessage());
            } finally {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    Log.e("Main", e.getMessage());
                }
            }
            return resultList;
        }
    }}

часть намерения create.java

  //takes the size of the list of spinners, for reference
            ArrayList<Integer> spinnerList = new ArrayList<>();
            for(int i = 0; i < mSpinners.size(); i++) {
                spinnerList.add(mSpinners.get(i).getSelectedItemPosition());

            }
            Bundle newBundle = new Bundle();
            newBundle.putIntegerArrayList("arraylist", spinnerList);
            Intent newIntent = new Intent(create.this, viewscreen.class);
            newIntent.putExtra("extraBundle", newBundle);

Ответы [ 6 ]

0 голосов
/ 08 сентября 2018

Убедитесь, что вы инициализировали свою активность в манифесте

и используйте прямо так

   ArrayList<Integer> list = getIntent.getIntegerArrayListExtra("")
0 голосов
/ 08 сентября 2018

Попробуйте получить пакет, как показано ниже: -

    Intent gotIntent = getIntent();
    Bundle bundle = gotIntent.getExtras();
    ArrayList<Integer> spinnerArrayList = bundle.getIntegerArrayList("arraylist");

Метод getBundleExtra("String") получает пакет с именем String. В то время как getExtras() получает пакет со всеми элементами, помещенными в массив. Поместите свой пакет с putExtra(Bundle bundle, String tag), чтобы getBundleExtra(String tag) вернул это значение.

Для проверки на ноль,

if(gotIntent != null && gotIntent.hasExtra("bundleExtras")){
      Bundle bundle = gotIntent.getExtras();
      ArrayList<Integer> spinnerArrayList = bundle.getIntegerArrayList("arraylist");

}
0 голосов
/ 08 сентября 2018

Попробуйте проверить нулевое значение. Возможно, намерение имеет значение null или пакет, который вы передали ему, равен null

Intent gotIntent = getIntent();
if ((gotIntent != null) && (gotIntent.getBundleExtra("extraBundle")  != null)) {
    Bundle bundle = gotIntent.getBundleExtra("extraBundle");
    if(bundle.containsKey("arraylist") {
       ArrayList<Integer> spinnerArrayList = bundle.getIntegerArrayList("arraylist");
    }

}
0 голосов
/ 08 сентября 2018

Проверьте коды в основном методе нажатия кнопки активности, убедитесь, что правильно поставили связку и данные. и ввиду активности предложите написать так:

Bundle bundle = getIntent().getBundleExtra("extraBundle");
if (bundle!=null) {
    if(bundle.containsKey("arraylist") {
       ArrayList<Integer> spinnerArrayList = bundle.getIntegerArrayList("arraylist");
       //do something
    }
} else {
     //log error info
}
0 голосов
/ 08 сентября 2018
    Intent gotIntent = getIntent();
      Bundle bundle = getIntent().getBundleExtra("extraBundle");

please print bundle. because the bundle is null then an exception is created 

for example:-
send data:-

String[] _string=new String[2];
_string[0]="MONDAY";
_string[1]="TUESDAY";
Intent _intent = new Intent(this, second.class);
Bundle bundle = new Bundle();
_intent .putExtra("strings", myStrings);
_intent .putExtras(bundle);               
startActivity(_intent );


receive data:-

Intent i = getIntent();
Bundle extras=i.getExtras();

if(extras != null)  //this line is necessary for getting any value
{
    String[] _Values = i.getStringArrayExtra("strings");
    Toast.makeText(this, "value="+_Values [0]+""+_Values [1], Toast.LENGTH_SHORT).show();
}
0 голосов
/ 08 сентября 2018

Можете ли вы использовать значение put arraylist как

Bundle bundle = new Bundle();  
bundle.putParcelableArrayList("arraylist", arraylist);

И получите значение массива, как показано ниже:

Bundle extras = getIntent().getExtras();
extras.getParcelableArrayList("arraylist"); 
Добро пожаловать на сайт PullRequest, где вы можете задавать вопросы и получать ответы от других членов сообщества.
...