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：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout
 3     xmlns:android="http://schemas.android.com/apk/res/android"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="wrap_content"
 7     android:orientation="vertical"
 8     tools:context="com.hs.example.exampleapplication.RadioButtonMain">
 9 
10     <LinearLayout
11         android:layout_width="match_parent"
12         android:layout_height="wrap_content"
13         android:orientation="horizontal"
14         android:gravity="center">
15 
16         <TextView
17             android:layout_width="wrap_content"
18             android:layout_height="match_parent"
19             android:gravity="center"
20             android:text="输入温度："/>
21         
22         <RadioGroup
23             android:id="@+id/unit"
24             android:layout_width="wrap_content"
25             android:layout_height="wrap_content"
26             android:orientation="horizontal">
27 
28             <RadioButton
29                 android:id="@+id/unitF"
30                 android:layout_width="wrap_content"
31                 android:layout_height="wrap_content"
32                 android:textSize="22sp"
33                 android:text="华氏"/>
34 
35             <RadioButton
36                 android:id="@+id/unitC"
37                 android:layout_width="wrap_content"
38                 android:layout_height="wrap_content"
39                 android:textSize="22sp"
40                 android:text="摄氏"/>
41 
42             <RadioButton
43                 android:id="@+id/unitK"
44                 android:layout_width="wrap_content"
45                 android:layout_height="wrap_content"
46                 android:textSize="22sp"
47                 android:text="绝对"/>
48 
49         </RadioGroup>
50 
51     </LinearLayout>
52 
53     <EditText
54         android:id="@+id/value"
55         android:layout_width="match_parent"
56         android:layout_height="wrap_content"
57         android:maxLength="9"
58         android:singleLine="true"
59         android:inputType="numberDecimal"/>
60 
61     <LinearLayout
62         android:layout_width="match_parent"
63         android:layout_height="wrap_content"
64         android:orientation="vertical">
65 
66         <TextView
67             android:id="@+id/degF"
68             android:layout_width="match_parent"
69             android:layout_height="wrap_content"
70             android:layout_weight="1"
71             android:gravity="center"
72             android:textSize="45sp"
73             android:maxLines="1"
74             android:text="@string/charF"/>
75 
76         <TextView
77             android:id="@+id/degC"
78             android:layout_width="match_parent"
79             android:layout_height="wrap_content"
80             android:layout_weight="1"
81             android:gravity="center"
82             android:textSize="45sp"
83             android:maxLines="1"
84             android:text="@string/charC"/>
85 
86         <TextView
87             android:id="@+id/degK"
88             android:layout_width="match_parent"
89             android:layout_height="wrap_content"
90             android:layout_weight="1"
91             android:gravity="center"
92             android:textSize="45sp"
93             android:maxLines="1"
94             android:text="K"/>
95 
96     </LinearLayout>
97 
98 </LinearLayout>

Java代码：

 1 public class RadioButtonMain extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener,TextWatcher{
 2 
 3     RadioGroup unit;
 4     EditText value;
 5 
 6     @Override
 7     protected void onCreate(Bundle savedInstanceState) {
 8         super.onCreate(savedInstanceState);
 9         setContentView(R.layout.activity_radiobutton_main);
10 
11         unit = this.findViewById(R.id.unit);
12         unit.setOnCheckedChangeListener(this);
13 
14         value = this.findViewById(R.id.value);
15         value.addTextChangedListener(this);
16 
17     }
18 
19     @Override
20     public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
21 
22     }
23 
24     @Override
25     public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
26 
27     }
28 
29     @Override
30     public void afterTextChanged(Editable editable) {
31         calc();
32     }
33 
34     @Override
35     public void onCheckedChanged(RadioGroup radioGroup, int i) {
36         calc();
37     }
38 
39     protected void calc(){
40         TextView degF = this.findViewById(R.id.degF);
41         TextView degC = this.findViewById(R.id.degC);
42         TextView degK = this.findViewById(R.id.degK);
43 
44         double f,c,k;
45 
46         if(unit.getCheckedRadioButtonId() == R.id.unitF){
47             f = Double.parseDouble(value.getText().toString());
48             c = (f-32)*5/9;         //华氏度转摄氏度
49             k = c + 273.15;         //绝对 = 摄氏度 + 273.15
50 
51         }else if(unit.getCheckedRadioButtonId() == R.id.unitC){
52             c = Double.parseDouble(value.getText().toString());
53             f = c*9/5+32;           //摄氏度转华氏度
54             k = c + 273.15;
55 
56         }else{
57             k = Double.parseDouble(value.getText().toString());
58             c = k - 273.15;
59             f = c*9/5+32;
60         }
61 
62         degC.setText(String.format("%.1f",c)+getResources().getString(R.string.charC));
63         degF.setText(String.format("%.1f",f)+getResources().getString(R.string.charF));
64         degK.setText(String.format("%.2f",k)+"K");
65 
66     }
67 
68 }

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。