Question

您好我是java和Android的新手，我目前正在学习Android作为学校项目。

我如何设置它以使editText框中的值仅设置为2位小数？

感谢您的帮助，史蒂芬。

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    //Finds varibles Id.
    e1 = (EditText) findViewById(R.id.inLow);
    e2 = (EditText) findViewById(R.id.inHigh);
    e3 = (EditText) findViewById(R.id.outLow);
    e4 = (EditText) findViewById(R.id.outHigh);
    e5 = (EditText) findViewById(R.id.var);
    e7 = (EditText) findViewById(R.id.out);

  TextView t8 = (TextView) findViewById(R.id.inText);
    TextView  t6 = (TextView) findViewById(R.id.outText);

    b9 = (Button) findViewById(R.id.con);

    initButton();
}
private void initButton() {
    b9.setOnClickListener(new View.OnClickListener() {
        // this one performs an action when our button is clicked. it performs whatever is below
        @Override
        public void onClick(View v) {
            String strA = e1.getText().toString();
            String strB = e2.getText().toString();
            String strC = e3.getText().toString();
            String strD = e4.getText().toString();
            String strE = e5.getText().toString();
            String strF = e7.getText().toString();


           //Check if value is in editText boxes.

            if (e1.getText().length() == 0 || e2.getText().length() == 0 || e3.getText().length() == 0 || e4.getText().length() == 0 || e5.getText().length() == 0 || e7.getText().length() == 0)  {


              if (e1.getText().length() == 0){
                e1.setHint("Enter Value!");
                }else if (e2.getText().length() == 0){
                    e2.setHint("Enter Value!");
                }else if (e3.getText().length() == 0){
                    e3.setHint("Enter Value!");
                }else if (e4.getText().length() == 0){
                    e4.setHint("Enter Value!");
                }else if (e5.getText().length() == 0){
                    e5.setHint("Enter Value!");
                }else if (e7.getText().length() == 0){
                    e7.setHint("Enter Value!");
                }
            } else {






                Double dblAnswer = doCalc(strA, strB, strC, strD, strE, strF);
                Double dblAnswer2 = doCalc2(strA, strB, strC, strD, strE, strF);

                TextView lblAnswer1 = (TextView) findViewById(R.id.outText);
                TextView lblAnswer2 = (TextView) findViewById(R.id.inText);



                e2.setText(String.format("%.2f", strA));
                e3.setText(String.format("%.2f", 3));
                e4.setText(String.format("%.2f", 4));
                e5.setText(String.format("%.2f", 5));
                e7.setText(String.format("%.2f", 6));
                t6.setText(String.format("%.2f", 7));
                t8.setText(String.format("%.2f", 8));*/
                String answer1 = String.valueOf(dblAnswer);
                String answer2 = String.valueOf(dblAnswer2);

                lblAnswer1.setText(answer1);
                lblAnswer2.setText(answer2);

            }

        }

    });}
public double doCalc(String a, String b, String c, String d,String e, String f ) {

    double dblA = Double.parseDouble(a);
    double dblB = Double.parseDouble(b);
    double dblC = Double.parseDouble(c);
    double dblD = Double.parseDouble(d);
    double dblE = Double.parseDouble(e);
    double dblF = Double.parseDouble(f);


    return (((dblD-dblC)/(dblB-dblA))*(dblE-dblA)+dblC);


}
public double doCalc2(String a, String b, String c, String d,String e, String f ) {

    double dblA = Double.parseDouble(a);
    double dblB = Double.parseDouble(b);
    double dblC = Double.parseDouble(c);
    double dblD = Double.parseDouble(d);
    double dblE = Double.parseDouble(e);
    double dblF = Double.parseDouble(f);


    return (((dblA-dblB)/(dblC-dblD))*(dblF-dblC))+dblA;

}

Answer 1

DecimalFormat formatter = new DecimalFormat("00");
String minformat = formatter.format(text);

Answer 2

使用此选项可以舍入到两位小数

public static double round2(double d) {
 return Math.round(d * 100) / 100.0;
}

Answer 3

NumberFormat课程将帮助您实现这一目标。

NumberFormat nf = NumberFormat.getInstance();
nf.setMinimumFractionDigits(2);
nf.setMaximumFractionDigits(2);

然后使用format（）方法设置文本：myTextView.setText(nf.format(myText));

您还可能希望在EditText中将输入格式检查为用户类型。要执行此操作，您应该addTextChangedListener(TextWatcher watcher)并听取用户输入事件。

Android：将我的代码设置为2位小数

3 个答案: