Question

当我遇到此错误时，我在android中使用RadioGroup，我无法找出原因：

Process: com.example.vinicius.crudnotas, PID: 16753
java.lang.NumberFormatException: Invalid double: ""

以下代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_inserir_notas);
    Button botao = (Button)findViewById(R.id.button);
    botao.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Controller crud = new Controller(getBaseContext());
            EditText nota1Id = (EditText)findViewById(R.id.editText);
            EditText nota2Id = (EditText)findViewById(R.id.editText3);
            String nota1String = nota1Id.getText().toString();
            String nota2String = nota2Id.getText().toString();
            double nota1 = Double.parseDouble(nota1String);
            double nota2 = Double.parseDouble(nota2String);
            double notaFinal  = (nota1+nota2)/2;
            String resultado;
            String escolha;
            RadioGroup group = (RadioGroup)findViewById(R.id.radio_materia);
            int op = group.getCheckedRadioButtonId();

            if(op==R.id.radio_php) {
                escolha = "php";
            }else if(op==R.id.radio_java) {
                escolha = "java";
            }else {
                escolha = "Escolha uma opcao";
            }
            Context context = getApplicationContext();
            CharSequence text = escolha;
            int duration = Toast.LENGTH_SHORT;

            Toast toast = Toast.makeText(context, text, duration);
            toast.show();

} }

我需要获取所选RadioGroup的文本才能进入银行

Answer 1

错误是nota1String或nota2String不包含任何有效的Double值或其字符串表示形式。由于这些是用户输入字段，因此请确保处理用户未在其中放置任何值的情况。以下是我认为您可以在onClick函数中进行的一些小改动：

try{
   String nota1String = nota1Id.getText().toString();
   String nota2String = nota2Id.getText().toString();
   //here I check if the string is empty, and then put "0" instead.
   double nota1 = Double.parseDouble((!nota1String.trim().isEmpty()?   nota1String: "0"));
   //again, here I check if the string is empty, and then put "0" instead.
   double nota2 = Double.parseDouble((!nota2String.trim().isEmpty()? nota2String: "0"));
   double notaFinal  = (nota1+nota2)/2;
}
catch(Exception e){
   //something went wrong above...
}

Answer 2

试试这段代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_inserir_notas);
    Button botao = (Button)findViewById(R.id.button);
    botao.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Controller crud = new Controller(getBaseContext());
            EditText nota1Id = (EditText)findViewById(R.id.editText);
            EditText nota2Id = (EditText)findViewById(R.id.editText3);
            String nota1String = nota1Id.getText().equals("")?"0":nota1Id.getText().toString();
            String nota2String = nota2Id.getText().equals("")?"0":nota2Id.getText().toString();
            double nota1 = Double.parseDouble(nota1String);
            double nota2 = Double.parseDouble(nota2String);
            double notaFinal  = (nota1+nota2)/2;
            String resultado;
            String escolha;
            RadioGroup group = (RadioGroup)findViewById(R.id.radio_materia);
            int op = group.getCheckedRadioButtonId();

            if(op==R.id.radio_php) {
                escolha = "php";
            }else if(op==R.id.radio_java) {
                escolha = "java";
            }else {
                escolha = "Escolha uma opcao";
            }
            Context context = getApplicationContext();
            CharSequence text = escolha;
            int duration = Toast.LENGTH_SHORT;

            Toast toast = Toast.makeText(context, text, duration);
            toast.show();
}
}

希望它会对你有所帮助:)。

在android中使用RadioGroup时出错

2 个答案: