需要用到的是RadioGroup和RadioButton，RadioButton放在RadioGroup里面：
public class SingleChoice extends AppCompatActivity {
private Button singleChoice;
private RadioButton rbA;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_single_choice);
rbA = (RadioButton)findViewById(R.id.rbA);
singleChoice = (Button)findViewById(R.id.btnSubmit);
singleChoice.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (rbA.isChecked()){
Toast.makeText(SingleChoice.this,"所选是正确的",Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(SingleChoice.this,"所选是错误的",Toast.LENGTH_SHORT).show();
}
}
});
}
}
