Question

我是Android Studio编码方面的新手，我刚刚了解了共享偏好。我的老师给我分配了一个单选按钮组（RadioGroup），当您选中其中一个按钮时，关闭应用程序，然后再次打开它，该按钮将保持选中状态。

就像您用EditText保存一个SharedPrefrences答案一样，我需要用RadioButton保存一个SharedPrefrences。

正如我所说的，我是新手，所以请保持简单的答案：）

-已解决-谢谢大家的回答！感谢您的评论，我找到了解决方案！：D

Answer 1

这是方法，您应该在单选组上获取 onCheckChangeListener ，以在其中获得所选的单选按钮！

注意！！！应该为所有内部无线电按钮提供ID

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
    {
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            // checkedId is the RadioButton selected
            RadioButton rb=(RadioButton)findViewById(checkedId);

            //textViewChoice.setText("You Selected " + rb.getText());
           // here the rb.getText() will give you the text and you can send it to your
           //sharedPreference with a new key value like you did with the editText values
        }
    });

然后，当您的应用启动时，您可以通过sharefPreference检入onCreate（），是否保存了该值，然后获取RadioButton并将其属性isSelected设置为true！我希望这很简单！

Answer 2

首先，您要像这样将监听器设置为RadioGroup：

RadioGroup radioGroup = (RadioGroup) findViewById(R.id.yourRadioGroup);        
    radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() 
    {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            // save id into your SharedPreferences
        }
    });

然后您可以从共享的首选项中的onCreate（）中恢复它，并调用radioGroup.check(id);。
因此，代码将如下所示：

SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
int checkedId = sharedPrefs.getInt("your key", 0);
radioGroup.check(checkedId);

请注意，此代码已简化。您需要添加支票等等

Answer 3

public class MainActivity extends AppCompatActivity {
   // this will be key for the key value pair
   public static final String BUTTON_STATE = "Button_State";
   // this is name of shared preferences file, must be same whenever accessing
   // the key value pair.
   public static final String MyPREFERENCES = "MyPrefs" ;

   SharedPreferences sharedpreferences;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      // helper method to open up the file.
      sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
      // grab the last saved state here on each activity start
      Boolean lastButtonState = sharedpreferences.getBoolean(BUTTON_STATE, false)
      RadioButton rb = (RadioButton) findViewById(R.id.radio_button);
      // restore previous state
      rb.setChecked(lastButtonState);
      // set a listener
      rb.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            // call this to enable editing of the shared preferences file
            // in the event of a change
            SharedPreferences.Editor editor = sharedpreferences.edit();
            Boolean isChecked = rb.isChecked();
            // use this to add the new state
            editor.putBoolean(BUTTON_STATE, isChecked);
            // save
            editor.apply();
         }
      });
   }
}

Answer 4

尝试一下

    RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radio_gropup);
    final SharedPreferences preferences = getSharedPreferences("saved", 0);

    radioGroup.check(preferences.getInt("CheckedID", 0));

    radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            SharedPreferences.Editor editor = preferences.edit();
            editor.putInt("CheckedId", checkedId);
            editor.apply();
        }
    });

关闭应用程序后如何保持单选按钮的检查-Android Studio

4 个答案: