试图从编辑文本和微调器中移动值

Question

I want to get the value from a edit text and values from 3 spinners and calculate the value. Below is the code I have so far, remember that I am beyond new at this. I do not know how to get the value rollPrice to equal B3 in the formula as it gives me an error since rollPrice is put into a string.

**Clarification edit. The slength, swidth, and sthick are values selected from spinners. the rollPrice is an edit text the user puts the price into and then selects the values from the 3 spinners, and the formula will compute the MSF price.

        @Override
        public void afterTextChanged(Editable arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                int arg3) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onTextChanged(CharSequence arg0, int arg1, int arg2,
                int arg3) {

            try{

                // Change the billBeforeTip to the new input

                rollCost = Double.parseDouble(arg0.toString());

            }

            catch(NumberFormatException e){

                rollCost = 0.0;

            }

    };

    private void calculate(){

         String B5 = swidth.getSelectedItem().toString();
         String B6 = slength.getSelectedItem().toString();
         String B4 = sthick.getSelectedItem().toString();

         MSF=1000/(Double.parseDouble(B5)/12*Double.parseDouble(B6))*Double.parseDouble(B‌​3);


    }

Answer 1

Because you have mentioned that you are using EditTexts. I would suggest you to use (your question is unclear, I have assumed swidth,slength and sthick are edittexts)

         String B5 = swidth.getText().toString();
         String B6 = slength.getText().toString();
         String B4 = sthick.getText().toString();

instead of

         String B5 = swidth.getSelectedItem().toString();
         String B6 = slength.getSelectedItem().toString();
         String B4 = sthick.getSelectedItem().toString();