Android 多微调器

Question

I'm sure I'm missing something simple, but I am having some logic issues with my code. I am working on a converter app. I will be using two spinners to select between to do conversions. Ex. inches to feet. I am using two simple methods to test before fleshing out all of the code. Right now if I select the value for SpinnerA in the app first, and then select the value for SpinnerB, it doesn't calculate. If I select SpinnerB first and then SpinnerA, it works. What am I missing?

    spinnerA = (Spinner)getView().findViewById(R.id.spinnerA);
    spinnerB = (Spinner)getView().findViewById(R.id.spinnerB);
    adapterA = ArrayAdapter.createFromResource(getContext(),
            R.array.conversions, android.R.layout.simple_spinner_item);
    adapterA.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    adapterB = ArrayAdapter.createFromResource(getContext(),
            R.array.conversions, android.R.layout.simple_spinner_item);
    adapterB.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinnerA.setAdapter(adapterA);
    spinnerB.setAdapter(adapterB);

    spinnerA.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

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

            tempA = parent.getItemAtPosition(position).toString();

            if (tempA.equals("Inches") && tempB.equals("Centimeters")){
                    textView.setText(String.valueOf(halfMyNum(100)));
            }

            else if (tempA.equals("Centimeters")){
                if (tempB.equals("Inches")){
                    textView.setText(String.valueOf(doubleMyNum(12)));
                }
            }

            else{
                textView.setText("Please select a valid option");
            }



            //Toast.makeText(getContext(), parent.getItemAtPosition(position)+ " Selected"
            //, Toast.LENGTH_LONG).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });

spinnerB.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        tempB = parent.getItemAtPosition(position).toString();

    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});
}

Answer 1

When you are selecting an item from spinnerA first, tempA is initialized and item listener for spinnerA is called but tempB is not yet initialized. Then, when you select item from spinnerB, tempB is initialized and item listener for spinnerB is called. In your case, you only called the method in item listener method for spinnerA, so when you select item from spinnerB nothing actually executes. One possible solution is to call the desired method in item listener for spinnerB as well.