Radiobutton Android

Question

我正在开发简单的BMI计算器，因为我通过单选按钮添加了性别对我的代码的影响，AVD意外停止。问题出在InterpretIMC函数上，我相信radiobutton的ID不读，不知道为什么！ 请帮助。

package com.example.calculadorimc;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.RadioGroup;
import android.widget.TextView;

public class MainActivity extends Activity {
    private RadioGroup rgsexo;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void calculateClickHandler(View view) {

        // make sure we handle the click of the calculator button

        if (view.getId() == R.id.botaoCalcular) {

         // get the references to the widgets
         EditText editPeso = (EditText)findViewById(R.id.editPeso);
         EditText editAltura = (EditText)findViewById(R.id.editAltura);
         TextView imcView = (TextView)findViewById(R.id.imcView);

         // get the users values from the widget references

         float peso = Float.parseFloat(editPeso.getText().toString());
         float altura = Float.parseFloat(editAltura.getText().toString());

         // calculate the bmi value

         float imcValue = calcularIMC(peso, altura);

         // interpret the meaning of the bmi value
         String imcInterpretation = interpretIMC(imcValue);

         // now set the value in the result text

         imcView.setText(imcValue + "-" + imcInterpretation);
        }
       }
       // the formula to calculate the BMI index

       // check for http://en.wikipedia.org/wiki/Body_mass_index
       private float calcularIMC (float peso, float altura) {

        return (float) (peso / (altura * altura));
       }

       // interpret what BMI means
       private String interpretIMC(float imcValue) {           

           int selectedId = rgsexo.getCheckedRadioButtonId();  // get the id

           switch (selectedId)   // switch on the button selected
           {
                case R.id.radioMasc:
                    if (imcValue < 16) {
                        return "Magreza Grave";
                       } else if (imcValue < 18.5) {

                        return "Magreza Leve";
                       } else if (imcValue < 25) {

                        return "Saudável";
                       } else if (imcValue < 30) {

                        return "Sobrepeso";
                       } else if (imcValue < 35){
                        return "Obesidade Grau I";
                       } else if (imcValue < 40){
                        return "Obesidade Grau II";
                       } else {
                        return "Obesidade Grau III";
                       }
                case R.id.radioFem:
                    if (imcValue < 16) {
                        return "Magreza Grave";
                       } else if (imcValue < 18.5) {

                        return "Magreza Leve";
                       } else if (imcValue < 25) {

                        return "Saudável";
                       } else if (imcValue < 30) {

                        return "Sobrepeso";
                       } else if (imcValue < 35){
                        return "Obesidade Grau I";
                       } else if (imcValue < 40){
                        return "Obesidade Grau II";
                       } else {
                        return "Obesidade Grau III";
                       }
           }
        return null;
       }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

这是我的xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <RadioGroup
        android:id="@+id/rgSexo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <RadioButton
            android:id="@+id/radioMasc"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="@string/radioMasc" />

        <RadioButton
            android:id="@+id/radioFem"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/radioFem" />
    </RadioGroup>

    <TextView
        android:id="@+id/alturaView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/alturaView" />

    <EditText
        android:id="@+id/editAltura"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="5"
        android:inputType="numberDecimal"
        android:text="@string/editAltura" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/pesoView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/pesoView" />

    <EditText
        android:id="@+id/editPeso"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="5"
        android:inputType="number"
        android:text="@string/editPeso" />

    <View
        android:layout_width="fill_parent"
        android:layout_height="2dip"
        android:layout_marginBottom="5dip"
        android:layout_marginTop="5dip"
        android:background="#111111" />

    <Button
        android:id="@+id/botaoCalcular"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="calculateClickHandler"
        android:text="@string/botaoCalcular" />

    <TextView
        android:id="@+id/imcView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/imcView"
        android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

Answer 1

在调用rgsexo方法之前初始化getCheckedRadioButtonId RadioGroup实例：

     rgsexo = (RadioGroup)findViewById(R.id.rgSexo);

Answer 2

你没有定义id ..，只需定义radiogroup的id

  rgsexo = (RadioGroup)findViewById(R.id.rgSexo);