从xml显示项目 <array-list> 根据用户选择

Question

So lets say I have spinner, from which I choose items, that are stored in string-array, and the user can choose from:

<string-array name="products_array">
    <item>Sugar</item>
    <item>Caster sugar</item>
    <item>Salt</item>
</string-array>

And I also have two more string-array lists, with another values:

 <string-array name="glass">
    <item>200</item>
    <item>180</item>
    <item>325</item>
</string-array>

and

<string-array name="tableSpoon">
    <item>25</item>
    <item>25</item>
    <item>30</item>
</string-array>

I have created the spinner and this is my onItemSelected method, which, as you can see, shows, which item from products_array list has been selected by users (by using log.i):

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    String selected = parent.getItemAtPosition(position).toString();
    Log.i("Spinner listener", "Item selected " + selected);
}

I have a layout file (fragment), in which I have the spinner and two textViews- one for glass array-list and one for tableSpoon array-list.

I want the user to select, lets say, Sugar, and for it to display from string-array glass accordingly 200 in my first TextView, and for the tableSpoon string-array 25 in my second TextView.

I want these values to be displayed in the exact order, as they all go on the list (Eg., Sugar goes with 200 and 25. Caster sugar goes with 180 and 25 etc.)

Without doubt, an if-else statement can be used, but given, that I will have quite a few values in all these lists, how can I do this more efficiently?

Answer 1

In your onItemSelected method get the position of the element selected for product array and save it in a variable like this

int index  = spinner1.getSelectedItemPosition(); // spinner1 is product spinner

and then get values from other two arrays for this position and set in your textviews like this

String [] array1 = getResources().getStringArray(R.array.glass);
  String [] array2 = getResources().getStringArray(R.array.tablespoon);

and then set values in your textviews

 textview1.setText(array1[index]);
    textview2.setText(array2[index]);

Answer 2

1. Read string-array glass and tableSpoon from XML and store it into two variable as below:

String [] glass = getResources().getStringArray(R.array.glass);
String [] tablespoon = getResources().getStringArray(R.array.tablespoon);

2. Inside onItemSelected() method, get the selected item position and use this position to get the value from array glass and tableSpoon .

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    ..........
    ..............

    // Set text
    firstTextView.setText(glass[position]);
    secondTextView.setText(tableSpoon[position]);
}

Hope this will help~