Question

需要一些帮助！我有一个微调器，用于确定用户是男性还是女性。我希望计算bmr。如果用户是男性，则与女性相比，bmr公式不同。因此，我试图创建一个textview，它将显示微调器项的字符串内容，因为无法在onItemSelected方法中访问该变量。

这就是为什么我有第二部分，我使用if-else语句基本上将文本与字符串进行比较，并希望将bmr传递给另一个活动，但这并不像我一样工作。 m默认情况下得到错误的值。

    spGender = (Spinner) findViewById(R.id.spinnerGender);
    final TextView tvGender = (TextView)findViewById(R.id.tvGenderTemp);
    spGender.setSelection(0);

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

        }


        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            AlertDialog alertDialog = new AlertDialog.Builder(UserProfile.this).create();
            alertDialog.setTitle("Alert");
            alertDialog.setMessage("Please select a gender!");
            alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
            alertDialog.show();
            spGender.setSelection(0);
        }
    });


    //BMR FORMULA PART II
    final double bmr;

    if ("Female".equals(tvGender.getText().toString()))

    {
        bmr = (655 + (13.7*userWeight) + (5.0*userHeight) - (6.8*userAge));
    }

    else
    {
        bmr = 66 + (13.7 * userWeight) + (1.8*userHeight) - (4.7*userAge);
    }


    Button btnUPSave = (Button)findViewById(R.id.btnUserProfileSave);
    btnUPSave.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(getApplicationContext(), "Saved!",
                    Toast.LENGTH_LONG).show();

            Intent in2 = new Intent(getApplicationContext(), CaloriesPage.class);
            in2.putExtra("mBMR",bmr);
            startActivity(in2);
        }
    });

Answer 1

直接从微调器获取所选项目并进行比较

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

        if ("Female".equals(spGender.getSelectedItem().toString())){
         bmr = (655 + (13.7*userWeight) + (5.0*userHeight) - (6.8*userAge));
        }else{
        bmr = 66 + (13.7 * userWeight) + (1.8*userHeight) - (4.7*userAge);
        }

    }


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

    }
});

Answer 2

 public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        String item = parent.getItemAtPosition(position).toString();
        tvGender.setText(item);
        if (item .equals("Female")){
            bmr = (655 + (13.7*userWeight) + (5.0*userHeight) - (6.8*userAge));
        }else{
            bmr = 66 + (13.7 * userWeight) + (1.8*userHeight) - (4.7*userAge);
        } 

 }

Answer 3

试试这个希望会有效

  Spinner spGender;
    double bmr;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        List<String> spinnerArray = new ArrayList<>();
        spinnerArray.add("male");
        spinnerArray.add("female");
        spGender = (Spinner) findViewById(R.id.spinnerGender);
        ArrayAdapter arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, spinnerArray);
        spGender.setAdapter(arrayAdapter);
        final TextView tvGender = (TextView) findViewById(R.id.tvGenderTemp);
        spGender.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String item = parent.getItemAtPosition(position).toString();
                tvGender.setText(item);
                //BMR FORMULA PART II
                double userWeight = 10;
                double userHeight = 20;
                double userAge = 35;
                if (spGender.getSelectedItem().equals("female"))
                {
                    bmr = (655 + (13.7 * userWeight) + (5.0 * userHeight) - (6.8 * userAge));
                } else {
                    bmr = 66 + (13.7 * userWeight) + (1.8 * userHeight) - (4.7 * userAge);
                }

            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
                alertDialog.setTitle("Alert");
                alertDialog.setMessage("Please select a gender!");
                alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
                alertDialog.show();
            }
        });
        Button btnUPSave = (Button) findViewById(R.id.btnUserProfileSave);
        btnUPSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "Saved!",
                        Toast.LENGTH_LONG).show();

                Intent in2 = new Intent(getApplicationContext(), Main2Activity.class);
                in2.putExtra("mBMR", bmr);
                startActivity(in2);
            }
        });

    }

如何在spinner setOnItemSelectedListener类中使用If-Else条件？

3 个答案: