全部-我很难获取 EditText 的值并将其弄乱以执行方程式和诸如舍入和乘法之类的任务。我听说 BigDecimal 是一种很好的方法，但是很难将变量转换为可以成为 BigDecimal 变量的类型（View->String->Float->BigDecimal），然后再将它们转换为一种类型它们可以在哪里输出（BigDecimal->？）。这是我的代码：
public class TippingActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void calculateNumbers(View view) throws ParseException {
// Bill
EditText text = (EditText)findViewById(R.id.edit_bill);
String value;
value = text.getText().toString();
float bill = Float.parseFloat(value);
BigDecimal billbd;
billbd = new BigDecimal(bill);
//Tip
EditText text2 = (EditText)findViewById(R.id.edit_tip);
String value2;
value2 = text2.getText().toString();
if(!value2.contains("."))
value2 = "."+value2;
float tip = Float.parseFloat(value2);
BigDecimal tipbd;
tipbd = new BigDecimal(tip);
//People
EditText text3 = (EditText)findViewById(R.id.edit_people);
String value3;
value3 = text3.getText().toString();
float people = Float.parseFloat(value3);
BigDecimal peoplebd;
peoplebd = new BigDecimal(people);
//Answer
TextView answer = (TextView) findViewById(R.id.answer);
//Answer to string
String answerstring;
answerstring = answer.getText().toString();
//Answer to Float
float answerfloat = Float.parseFloat(answerstring);
//Answer to BigDecimal
BigDecimal answerbig;
answerbig = new BigDecimal(answerfloat);
answerbig.setScale(2, RoundingMode.HALF_UP);
answerbig = billbd.multiply(tipbd).add(billbd).divide(peoplebd);
//Answer to String
String answerfrombd = answerbig.getText().toString();
answer.setText(answerfrombd);
}
}
在底部的第二行代码中，我得到一个错误
`String answerfrombd = answerbig.getText().toString();`
因为我不能从 BigDecimal 转到 String。有任何想法吗？提前致谢！