[安卓] 4、CheckBox、RadioButton和Toast简单用法

 1 //使用状态改变检查监听器
 2 public class MainActivity extends Activity implements OnCheckedChangeListener {
 3     private CheckBox cb1, cb2, cb3;//创建3个CheckBox对象
 4 
 5     @Override
 6     public void onCreate(Bundle savedInstanceState) {
 7         super.onCreate(savedInstanceState);
 8         setContentView(R.layout.main);
 9         //实例化3个CheckBox
10         cb1 = (CheckBox) findViewById(R.id.cb1);
11         cb2 = (CheckBox) findViewById(R.id.cb2);
12         cb3 = (CheckBox) findViewById(R.id.cb3);
13         cb1.setOnCheckedChangeListener(this);
14         cb2.setOnCheckedChangeListener(this);
15         cb3.setOnCheckedChangeListener(this);
16     }
17 
18     //重写监听器的抽象函数
19     @Override
20     public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
21         //buttonView 选中状态发生改变的那个按钮
22         //isChecked 表示按钮新的状态（true/false）
23         if (cb1 == buttonView || cb2 == buttonView || cb3 == buttonView) {
24             if (isChecked) {
25                 //显示一个提示信息
26                 toastDisplay(buttonView.getText() + "选中");
27 
28             } else {
29                 toastDisplay(buttonView.getText() + "取消选中");
30             }
31         }
32     }
33 
34     public void toastDisplay(String str) {
35         Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
36     }
37 }

 1 //使用状态改变监听器
 2 public class MainActivity extends Activity implements OnCheckedChangeListener {
 3     private RadioButton rb1, rb2, rb3;
 4     private RadioGroup rg;
 5 
 6     @Override
 7     public void onCreate(Bundle savedInstanceState) {
 8         super.onCreate(savedInstanceState);
 9         setContentView(R.layout.main);
10         rb1 = (RadioButton) findViewById(R.id.rb1);
11         rb2 = (RadioButton) findViewById(R.id.rb2);
12         rb3 = (RadioButton) findViewById(R.id.rb3);
13         rg = (RadioGroup) findViewById(R.id.radGrp);
14         rg.setOnCheckedChangeListener(this);//将单选组绑定监听器
15     }
16 
17     //重写监听器函数
18     /** 
19      * @param group：指单选组
20      * @param group：指单选组中发生状态改变的RadioButton的内存ID！
21      */
22     @Override
23     public void onCheckedChanged(RadioGroup group, int checkedId) { 
24         if (group == rg) {//因为当前程序中只有一个RadioGroup，此步可以不进行判定
25             String rbName = null; 
26             if (checkedId == rb1.getId()) {
27                 rbName = rb1.getText().toString();
28             } else if (checkedId == rb2.getId()) {
29                 rbName = rb2.getText().toString();
30             } else if (checkedId == rb3.getId()) {
31                 rbName = rb3.getText().toString();
32             }
33             Toast.makeText(this, "选择了下标为“" + rbName + "”的单选按钮", 
34                     Toast.LENGTH_LONG).show();
35         }
36     }
37 }

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="vertical"
 4     android:layout_width="fill_parent"
 5     android:layout_height="fill_parent"
 6     >
 7     <RadioGroup
 8         android:id="@+id/radGrp"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content">
11         <RadioButton  
12             android:layout_width="fill_parent" 
13             android:layout_height="wrap_content" 
14             android:text="RadioButton1"
15            android:id="@+id/rb1"
16             />
17         <RadioButton  
18             android:layout_width="fill_parent" 
19             android:layout_height="wrap_content" 
20             android:text="RadioButton2"
21              android:id="@+id/rb2"
22             />
23         <RadioButton  
24             android:layout_width="fill_parent" 
25             android:layout_height="wrap_content" 
26             android:text="RadioButton3"
27              android:id="@+id/rb3"
28             />
29     </RadioGroup>
30 </LinearLayout>