Android-----RadioButton单选使用（实现简单温度转换）

废话少说，直接上代码：

xml布局文件代码：

 <?xml version="1.0" encoding="utf-8"?>
 <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="com.hs.example.exampleapplication.RadioButtonMain">

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         android:gravity="center">

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:gravity="center"
             android:text="输入温度："/>

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

             <RadioButton
                 android:id="@+id/unitF"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:textSize="22sp"
                 android:text="华氏"/>

             <RadioButton
                 android:id="@+id/unitC"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:textSize="22sp"
                 android:text="摄氏"/>

             <RadioButton
                 android:id="@+id/unitK"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:textSize="22sp"
                 android:text="绝对"/>

         </RadioGroup>

     </LinearLayout>

     <EditText
         android:id="@+id/value"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:maxLength=""
         android:singleLine="true"
         android:inputType="numberDecimal"/>

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="vertical">

         <TextView
             android:id="@+id/degF"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_weight=""
             android:gravity="center"
             android:textSize="45sp"
             android:maxLines=""
             android:text="@string/charF"/>

         <TextView
             android:id="@+id/degC"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_weight=""
             android:gravity="center"
             android:textSize="45sp"
             android:maxLines=""
             android:text="@string/charC"/>

         <TextView
             android:id="@+id/degK"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_weight=""
             android:gravity="center"
             android:textSize="45sp"
             android:maxLines=""
             android:text="K"/>

     </LinearLayout>

 </LinearLayout>

Java代码：

 public class RadioButtonMain extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener,TextWatcher{

     RadioGroup unit;
     EditText value;

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

         unit = this.findViewById(R.id.unit);
         unit.setOnCheckedChangeListener(this);

         value = this.findViewById(R.id.value);
         value.addTextChangedListener(this);

     }

     @Override
     public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

     }

     @Override
     public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

     }

     @Override
     public void afterTextChanged(Editable editable) {
         calc();
     }

     @Override
     public void onCheckedChanged(RadioGroup radioGroup, int i) {
         calc();
     }

     protected void calc(){
         TextView degF = this.findViewById(R.id.degF);
         TextView degC = this.findViewById(R.id.degC);
         TextView degK = this.findViewById(R.id.degK);

         double f,c,k;

         if(unit.getCheckedRadioButtonId() == R.id.unitF){
             f = Double.parseDouble(value.getText().toString());
             c = (f-)*/;         //华氏度转摄氏度
             k = c + 273.15;         //绝对 = 摄氏度 + 273.15

         }else if(unit.getCheckedRadioButtonId() == R.id.unitC){
             c = Double.parseDouble(value.getText().toString());
             f = c*/+;           //摄氏度转华氏度
             k = c + 273.15;

         }else{
             k = Double.parseDouble(value.getText().toString());
             c = k - 273.15;
             f = c*/+;
         }

         degC.setText(String.format("%.1f",c)+getResources().getString(R.string.charC));
         degF.setText(String.format("%.1f",f)+getResources().getString(R.string.charF));
         degK.setText(String.format("%.2f",k)+"K");

     }

 }

运行效果：

该例子还存在一些问题，这里就不指出了，运行一遍自会发现问题所在，最好能够自行解决。