从微调器创建计算器

Question

我创建了两个微调器，用户可以在其中 select 一种膳食类型，然后 select 一种食物（例如 'Breakfast' 和 'Porridge'）。然后我需要用用户在编辑文本中输入的重量来计算食物卡路里，但我不确定我是怎么做到的。

如何将微调器选项与数字相关联？

public class MainActivity3 extends ActionBarActivity {

    EditText num1;
    EditText num2;
    EditText num3;
    EditText num4;
    EditText num5;
    Button btnSave;
    EditText calorieResult;


    public Spinner catspinner, planspinner3, planspinner1, planspinner2;

    protected void onCreate(Bundle mbfSplash) {
        super.onCreate(mbfSplash);
        setContentView(R.layout.addmeal);

        chooseCategory();
        chooseBreakfast();
        chooseLunch();
        chooseDinner();
        chooseSnack();
    }

    public void chooseCategory() {

        catspinner = (Spinner) findViewById(R.id.catspinner);
        ArrayAdapter<CharSequence> catAdapter = ArrayAdapter.createFromResource(this, R.array.ducategory, android.R.layout.simple_spinner_item);
        catAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        catspinner.setAdapter(catAdapter);
        catspinner.setOnItemSelectedListener(new planOnClickListener());
    }

    private void chooseBreakfast() {
        planspinner1 = (Spinner) findViewById(R.id.planspinner);
        List<String> planlist = new ArrayList<String>();
        planlist.add("Porridge-40g/140cal");
        planlist.add("Coffee-10g/10cal");
        planlist.add("Toast-30g/87cal");
        ArrayAdapter<String> planAdapter1 = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, planlist);
        planAdapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        planspinner1.setAdapter(planAdapter1);
    }

    private void chooseLunch() {

        planspinner2 = (Spinner) findViewById(R.id.planspinner);
        List<String> planlist1 = new ArrayList<String>();
        planlist1.add("Salad-50g/40cal");
        planlist1.add("Sandwich-50g/200cal");
        ArrayAdapter<String> planAdapter2 = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, planlist1);
        planAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        planspinner2.setAdapter(planAdapter2);
    }

    private void chooseDinner() {

        planspinner2 = (Spinner) findViewById(R.id.planspinner);
        List<String> planlist2 = new ArrayList<String>();
        planlist2.add("Curry-100g/400cal");
        planlist2.add("Pasta-40g/160cal");
        planlist2.add("Pizza100g/220cal");
        ArrayAdapter<String> planAdapter3 = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, planlist2);
        planAdapter3.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        planspinner2.setAdapter(planAdapter3);
    }

    private void chooseSnack() {
        planspinner1 = (Spinner) findViewById(R.id.planspinner);
        List<String> planlist = new ArrayList<String>();
        planlist.add("Crisps-30g/70cal");
        planlist.add("Chocolate-100g/210cal");
        ArrayAdapter<String> planAdapter1 = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, planlist);
        planAdapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        planspinner1.setAdapter(planAdapter1);
    }

    public class planOnClickListener implements OnItemSelectedListener {

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

            parent.getItemAtPosition(pos);

            if (pos == 0) {
                chooseBreakfast();
            } else if (pos == 1) {
                chooseLunch();
            } else if (pos == 2) {
                chooseDinner();
            } else if (pos == 3) {
                chooseSnack();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }
    }


}

Answer 1

我在没有代码编辑器的情况下执行此操作，因此请原谅语法错误，但通常您应该使用一个对象来存储相关数据。为您的微调器使用自定义适配器。这里有一些代码可以帮助您入门。

您应该创建一个名为 Food 的对象。

public class Food {
int mCalories;
String mName;

public Food(String name, int calories) {
    mName= name;
    mCalories = calories;
    }
}

现在您可以为微调器使用自定义数组适配器。

public class FoodArrayAdapter extends ArrayAdapter<Food> {

private List<Food> mItems;
private Context mContext;
private int mResource;

public FoodArrayAdapter(Context ctx, int resource, List<Food> items) {
    super(activity, resource);
    mItems = items;
    mContext = ctx;
    mResource = resource;
}

@Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
    //You could use a view holder pattern here, won't really matter for a simple text spinner.
    Food item = mItems.get(position);
    LayoutInflater inflater = (LayoutInflater) mContext
    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflater.inflate(mResource, parent);
    TextView textView = (TextView) v.findViewById(android.R.id.text1);

    if (item != null) {
        textView.setText(food.getName());
    }

    return v;
}

@Override
public Food getItem(int position) {
    return items.get(position);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    return getDropDownView(int position, View convertView, ViewGroup parent);
    //or make another view for when the spinner is expanded
}

@Override
public int getCount() {
    return mItems.getSize();
}
}

现在只需将自定义适配器与主 activity 中的微调器相关联即可。

Spinner spinner = (Spinner) layout.findViewById(R.id.myspinner1);
spinner.setAdapter(new FoodAdapter(this, android.R.layout.simple_spinner_item, list);
spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id){
      Food food = (Food) parent.getItemAtPosition(pos);
      //Do whatever you need to do with selected value.  You have reference to both the food and the calories.
    }
    public void onNothingSelected(    AdapterView<?> parent){

    }
  }

);

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