使用ListView从另一个Activity打印ArrayList

Question

I'm trying to print a string from ArrayList in my another Activity using ListView. I passed a key and values in my intent variable. Using this.

MainActivity

ArrayList<String> arrayList = new ArrayList<String>();
Intent intent = new Intent(getApplicationContext(), ViewCart.class);

mealOneIncrement++;
quantityOne.setText(Integer.toString(mealOneIncrement));
mealOneCost = mealOneIncrement * mealOnePrice;
price.setText(Double.toString(mealOneCost));

String mealOneSummayName = name.toString();
String mealOneSummaryDescription = description.toString();
String mealOneSummaryQuantity = String.valueOf(mealOneIncrement);
String mealOneSummaryCost = String.valueOf(mealOneCost);

arrayList.add(mealOneSummayName);
arrayList.add(mealOneSummaryDescription);
arrayList.add(mealOneSummaryQuantity);
arrayList.add(mealOneSummaryCost);

intent.putExtra("data", arrayList);

As you can see here I passed arrayList variable as value for able to passed this from another Activity.

SecondActivity

ListView listView = (ListView) findViewById(R.id.listView);

String[] mealSummary = {};
ArrayAdapter adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, mealSummary);
Bundle bundle = getIntent().getExtras();

String data = bundle.getString("data");
listView.setAdapter(adapter);

I'm little bit confuse in this part String data = bundle.getString("data"); I'm not sure if I'm passing a correct variable to my ListView so I can able to show the arrayList variable in my ListView . Am I doing it wrong? Any help would appreciated :)

Answer 1

There are some problems with your code:

intent.putExtra("data", arrayList);

you are putting inside the bundle an arrayList of String, but then

String data = bundle.getString("data");

you are getting just a String. You need to use bundle.getStringArrayList("data") .

ArrayList<String> data = bundle.getStringArrayList("data")

Also (not related to your problem), I recommend to use

Intent intent = new Intent(this, ViewCart.class);

instead of

Intent intent = new Intent(getApplicationContext(), ViewCart.class);

Answer 2

Pass Arraylist as putStringArrayListExtra,

    Intent intent = new Intent(this, ViewCart.class);
    intent.putStringArrayListExtra("data", arrayList);
    startActivity(intent);

Get your ArrayList using getStringArrayListExtra,

    arrayList = getIntent().getStringArrayListExtra("data");

Answer 3

You could modify this a bit.

In your secondActivity get the data like

ArrayList<String> data = getIntent().getSerializableExtra("data");

Now you got your data in an arrayList. If you wish to add this data to mealSummary then use,

mealSummary = (String[]) data.toArray();

Don't forget to call adapter.notifyDataSetChanged()