CODEWITHSUNDEEP
javaandroidlistviewandroid-activity
Darryl Fernandes
Darryl Fernandes

Reputation: 161

Add Items to a Listview which is in another activity(Adds Only 1 entry)

I am trying to make an app in which I want to pass a value from an editText(MainActivity.java) to a listView(bestFitActivity.java) which is placed in another activity. The issue with my code is that it passes only one value to the listView. When I enter a new value it just replaces the previous value.

MainActivity.java

public class MainActivity extends AppCompatActivity {
    int i = 0;
    String getChunkSize;
    ArrayList<String> chunkSizeArray = new ArrayList<>();
    EditText chunkSize;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button chunkSave = (Button)findViewById(R.id.chunkSave);
        Button processSave = (Button)findViewById(R.id.processSave);
        Button bestFitDirector = (Button)findViewById(R.id.bestFitdirector);
        Button worstFitDirector = (Button)findViewById(R.id.worstFitdirector);
        Button firstFitDirector = (Button)findViewById(R.id.firstFitDirector);

        EditText processSize = (EditText)findViewById(R.id.processSize);
        chunkSize = (EditText)findViewById(R.id.chunkSize);

        chunkSave.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                i++;
                Log.d("Manager" , "%d" +i);


                getChunkSize = chunkSize.getText().toString();
                //Log.d("Manager" , "" +getChunkSize);


                if(getChunkSize == null ) {
                    Toast.makeText(getBaseContext(), "Empty Input", Toast.LENGTH_SHORT).show();
                }
            }
        });

        bestFitDirector.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent myIntent =  new Intent(MainActivity.this , bestFitActivity.class);
                myIntent.putExtra("chunkSizeArray" , getChunkSize );
                startActivity(myIntent);
            }
        });

        /*worstFitDirector.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent myIntent2 = new Intent (MainActivity.this , worstFitActivity.class);
                startActivity(myIntent2);
            }
        });

        firstFitDirector.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent myIntent3 = new Intent (MainActivity.this , firstFitActivity.class);
                startActivity(myIntent3);
            }

        });*/
    }
}

bestFitActivity.java

public class bestFitActivity extends AppCompatActivity {
    String chunkSIZE;
    ArrayList<String> chunkSizeArray = new ArrayList<>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_best_fit);

        ListView blockSize = (ListView)findViewById(R.id.blockSize);
        ListView finalProcessList  = (ListView)findViewById(R.id.finalprocesslist);

        chunkSIZE = getIntent().getExtras().getString("chunkSizeArray");
        Log.d("Manager" , " "+chunkSIZE);

        chunkSizeArray.add(chunkSIZE);
        Log.d("Manager" , ""+chunkSIZE);

        ArrayAdapter<String> adapter = new ArrayAdapter<>(bestFitActivity.this , android.R.layout.simple_expandable_list_item_1 , chunkSizeArray);
        blockSize.setAdapter(adapter);
        adapter.notifyDataSetChanged();
        //((EditText)findViewById(R.id.chunkSize)).setText(" ");
        //EditText tv = (EditText) findviewbyID(R.id.)
    }
}

PS: This code is not complete

Upvotes: 2

Views: 73

Answers (2)

user10937486
user10937486

Reputation:

Each time you click the button a new activity, with a new empty chunkSize ArrayList is, created with just the single value.

You could, each time the button is clicked, add to the chunkSizeArray in the MainActivity and then send a counter and the values of the array in individual intentExtras.

And then retrieve and build the ArrayList from all the intent extras in the bestFitActivity.

This is how you could do it 

public class MainActivity extends AppCompatActivity {

    public static final String INTENTKEY_ARRAYELEMENTS = "arrayelemets";
    public static final String INTENYKEY_ELEMENTX = "element_";
    private static ArrayList<String> chunkSizeArray = new ArrayList<>();
    Button bestFitDirector;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bestFitDirector = (Button)findViewById(R.id.bestFitdirector);

        bestFitDirector.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                chunkSizeArray.add("Test" + String.valueOf(chunkSizeArray.size() + 1));
                Intent myitent = new Intent(MainActivity.this,bestFitActivity.class);
                myitent.putExtra(INTENTKEY_ARRAYELEMENTS, chunkSizeArray.size());
                for (int i=0; i < chunkSizeArray.size(); i++) {
                    myitent.putExtra(INTENYKEY_ELEMENTX + String.valueOf(i),chunkSizeArray.get(i));
                }
                startActivity(myitent);
            }
        });
    }
}

and 

public class bestFitActivity extends AppCompatActivity {

    ArrayList<String> chunkSizeArray = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_best_fit);

        Intent mypassedIntent = getIntent();

        int elements = mypassedIntent.getIntExtra(MainActivity.INTENTKEY_ARRAYELEMENTS,0);
        for (int i = 0; i < elements; i++) {
            chunkSizeArray.add(mypassedIntent.getStringExtra(MainActivity.INTENYKEY_ELEMENTX + String.valueOf(i)));
        }
        Toast.makeText(this,"The number of strings in the chukSizeArray is " + String.valueOf(chunkSizeArray.size()),Toast.LENGTH_SHORT).show();
        for (String s: chunkSizeArray) {
            Log.d("chunkSizeArray Value",s);
        }
    }
}

After clicking 5 times (click back to return to the MainActivity) the log is 

2019-03-10 17:19:51.687 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test1

2019-03-10 17:19:56.362 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test1
2019-03-10 17:19:56.362 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test2

2019-03-10 17:19:59.877 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test1
2019-03-10 17:19:59.877 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test2
2019-03-10 17:19:59.877 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test3

2019-03-10 17:20:03.007 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test1
2019-03-10 17:20:03.007 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test2
2019-03-10 17:20:03.007 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test3
2019-03-10 17:20:03.007 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test4

2019-03-10 17:20:06.266 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test1
2019-03-10 17:20:06.266 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test2
2019-03-10 17:20:06.266 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test3
2019-03-10 17:20:06.266 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test4
2019-03-10 17:20:06.266 11271-11271/com.example.bestfitapp D/chunkSizeArray Value: Test5

gaps added to split the clicks up

A simpler way is to use the putStringArrayListExtra along with the getStringArrayListExtra methods, which basically does the loops on your behalf.

So with main activity having 

 public static final String INTENTKEY_ARRAY = "bestfitarray";

In the onClick listener you could have :-

myitent.putStringArrayListExtra(INTENTKEY_ARRAY,chunkSizeArray);

Along with 

myitent.putStringArrayListExtra(INTENTKEY_ARRAY,chunkSizeArray);

in the bestFitActivity.

Upvotes: 3

PushpikaWan
PushpikaWan

Reputation: 2545

There is a simple hack you can do

change ArrayList<String> chunkSizeArray = new ArrayList<>();

to static like private static ArrayList<String> chunkSizeArray = new ArrayList<>();

Upvotes: 1

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