java - android:计算双倍百分比？

Question

我想计算百分比。但它给了我错误的结果(2.78674E7)。

以下是我的代码:

public class DetailActivity extends AppCompatActivity {

    private Button btn_pre_payment;
    private EditText et_pre_payment;

    private double monthlyPayment;
    private double allPayment = 139337000;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_detail);
        btn_pre_payment = (Button)findViewById(R.id.bt_prepayment);
        et_pre_payment = (EditText)findViewById(R.id.et_prepayment);

        btn_pre_payment.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(et_pre_payment.getText().length() > 0){

                    float value = Float.valueOf(et_pre_payment.getText().toString());
                    if(value >= 10){

                        InputMethodManager in = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                        in.hideSoftInputFromWindow(et_pre_payment.getApplicationWindowToken(),InputMethodManager.HIDE_NOT_ALWAYS);


                            **monthlyPayment = (allPayment / 100f) * value;
                            tvMonthlyPaymentH.setText(String.valueOf(monthlyPayment));
                            remainderPayment -= monthlyPayment;**

                        }

                    } else Toast.makeText(DetailActivity.this, "Low is 10%!", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(DetailActivity.this, "Enter value!", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

为什么不能计算出正确的结果？它给了我 2.78674E7。我想计算百分比。

Answer 1

首先，你的数学是错误的。它应该是值/总计*100，而不是值*总计/100。