Android-检查数组是否具有此值，获取位置并发送多余的意图到下一个活动片段

Question

Refering to this question has been asked Android - Check whether a value exist in an Array

So basically, I have 3 arrays in my FragmentActivity which are:

    String[] productName = {"Bread", "Butter", "Cadburry", "Tin Spinach", "Bulla Ice Cream", "Kit Kat Jam", "Chili Sauce", "Jasmine Rice", "Nutela", "Logan Tin" };
    String[] expiryDate = {"27/September/2017", "30/September/2017", "30/October/2017", "28/September/2018", "2/January/2018", "29/December/2017", "27/September/2017", "28/September/2017", "13/February/2018", "20/December/2017"};
    int[] images = {R.drawable.i1, R.drawable.i2, R.drawable.i3, R.drawable.i4, R.drawable.i5, R.drawable.i6, R.drawable.i7, R.drawable.i8, R.drawable.i9, R.drawable.i10};

I want to get all postition in "expiryDate[]" which contains value = "27/September/2017".

After getting the postion of the element in expiryDate[], I want to use the postion obtained from expiryDate[] for productName[] and images[] as well, to get the value based on the same pasition in expiryDate[].

At the end I want to intent the values obtained from productName[], images[], and expiryDate[] to another FragmentActivity and put them into new arrays.

Can anybody please tell me how to code this scenario ? I really appreciate it.

Answer 1

Try this .....

int position=-1;

position= Arrays.asList(array).indexOf("27/September/2017");
String name , image;
if(position>=0){
name = productName [position];
image = images [position];
}

EDIT:- please have look at this .....

>  for(int i=0;i<expiryDate.lenght;i++){
>     if(expiryDate[i].equals("27/September/2017"))
>     {
>         // do opeartion here 
          // add all values in new arrays
          // send all new arrays to the next activity.
>     }
>     }

OR

    ArrayList<Int> positions =  new ArrayList<>();
    >  for(int i=0;i<expiryDate.lenght;i++){
    >     if(expiryDate[i].equals("27/September/2017"))
    >     {
    >        positions.add(i);
             // send all your existing array list with this positions array list to other activity
    >     }
    >     }

Hope it will help ...

Answer 2

Getting the images and product names:

ArrayList<String> expiredProductNames = new ArrayList<>();
ArrayList<Integer> expiredProductImages = new ArrayList<>();

String expiredDate = "27/September/2017";

for (int i = 0; i < expiryDate.length; i++) {
    if (expiryDate[i].equals(expiredDate)) {
        expiredProductNames.add(productName[i]);
        expiredProductImages.add(images[i]);
    }
}

Creating intent:

Intent intent = new Intent(FragmentActivityA.this, FragmentActivityB.class);
intent.putStringArrayListExtra("productNames", expiredProductNames);
intent.putIntegerArrayListExtra("images", expiredProductImages);

Retrieving values from intent in second FragmentActivity:

ArrayList<String> productNames;
ArrayList<Integer> images;

Intent intent = getIntent();
if (null != intent) {
    productNames = intent.getStringArrayListExtra("productNames");
    images = intent.getIntegerArrayListExtra("images");
}

Note: It is better to use a class to encapsulate the data so there is only one list to iterate and propagate like other suggestions here.

Answer 3

To get the positions of the item in the array follow the below code

  String[] expiryDate = {"27/September/2017", "30/September/2017", "30/October/2017", "28/September/2018", "2/January/2018", "29/December/2017", "27/September/2017", "28/September/2017", "13/February/2018", "20/December/2017"};

    private List<Integer> postition = new ArrayList<>();

    for (int i = 0; i < expiryDate.length; i++) {
                if (expiryDate[i].equals("27/September/2017")) {
                    postition.add(i);
                }

      }
 Log.i("array positions", postition.toString());

With this given expireDate array you get the values 0 and 6 in the positions array. Now to get the values from productName and images use the below code

private List<String> products = new ArrayList<>();
for (int i = 0; i < postition.size(); i++) {
            products.add(productName[postition.get(i)]);
        }
Log.e("products", products.toString());

Now you get values Bread and Chilli Sauce for the existing productName array. Do the same for images as well.

Hope this helps.

Answer 4

If those three arrays are related, you should really leverage encapsulation to maintain the relationship between the data. It would be easier to maintain and read. It should allow you to mutate the data without having to worry about keeping 3 arrays in sync (to save you from hitting that inevitable index out of bounds problem)

class Product {

    // you probably want getters/setters for these
    public String name;
    public String expiration;
    public int drawableId;

    public Product(String name, String expiration, int drawableId){
        this.name = name;
        this.expiration = expiration;
        this.drawableId = drawableId;
    }
}

After you do that, it's much easier to filter one large list:

List<Product> myProducts = ...;
List<Product> filteredProducts = new ArrayList<>();

for (Product product : myProducts){
    if (product.expiration.equals("27/September/2017")){
        filteredProducts.add(product);
    }
}
// by now, filteredProducts should contain all the items you wanted

If you have access to rxjava, java8, or guava, you can make it a little cleaner:

rxjava

List<Product> myProducts = ...;
List<Product> filteredProducts = Observable.fromIterable(myProducts)
    .filter(product -> product.expiration.equals("27/September/2017"))
    .toList()
    .blockingGet();
// by now, filteredProducts should contain all the items you wanted

java 8

List<Product> myProducts = ...;
List<Product> filteredProducts = myProducts.stream()
    .filter(product -> product.expiration.equals("27/September/2017"))
    .collect(Collectors.toList());
// by now, filteredProducts should contain all the items you wanted

guava

List<Product> myProducts = ...;
List<Product> filteredProducts = Collections2.filter(
        myProducts,
        (product) -> product.expiration.equals("27/September/2017"));
// by now, filteredProducts should contain all the items you wanted

So, if you leverage encapsulation, now all you need to do to get your product names are:

for(Product product : filteredProducts){
    String productName = product.name;
    // do whatever you wanted with this data
}