如果未选中单选按钮，则阻止提交表单

Question

正在开发一款教育类安卓应用。一个通过EditText 输入、单选按钮和CheckBox 提供答案。

我想检查RadioGroup，当没有点击RadioButton 时，它会提示学生并阻止提交。我在EditText 中成功了，但在RadioButton 中没有成功。

public void checkEmptyButtons(View view){
  RadioGroup rg = (RadioGroup) findViewById(R.id.myRg);
    if (rg.getCheckedRadioButton()==-1{

    // this is where I have a problem
    //I don't even know how to search on the                     //dev.anderoid site
        }
    }

这就是卡住的地方。提前致谢 .

Answer 1

使用getCheckedRadioButtonId() 代替getCheckedRadioButton()。

if (rg.getCheckedRadioButtonId() == -1) {
    //no radio buttons are checked
}
else {
    //any one of the radio buttons is checked
}

Answer 2

你需要radioGroup选中Change Listener：

rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
              //here you will get callback everytime radio button is checked along with id. You can have boolean checked here to know if any of your radio button is checked


            }
        });