android - ラジオボタンの選択は保存されません Android

Question

ラジオ ボタン付きの警告ダイアログ ボックスを作成しました。ラジオ ボタンのトラック リストを選択すると、次の選択時にトラックが記憶されないため、現在再生中のトラックを知ることができません。int currentselection = -1; コードを確認して、私のコードに問題があるかどうか教えてください。前もって感謝します..

public class MainActivity extends Activity {
Button b1;
int currentselection = -1;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    b1 = (Button) findViewById(R.id.button1);
    final CharSequence[] items = { "Track #1", "Track #2","Track #3" };

    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Select Track");
    builder.setIcon(R.drawable.ic_launcher);

    builder.setNeutralButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    }); 
    builder.setSingleChoiceItems(items, currentselection,
            new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface mdialog, int item) {
                    // TODO Auto-generated method stub
                    switch (item) {
                    case 0:
                        currentselection = 0;
                        Toast.makeText(getApplicationContext(),
                                items[item], Toast.LENGTH_SHORT).show();
                        break;
                    case 1:
                        currentselection = 1;
                        Toast.makeText(getApplicationContext(),
                                items[item], Toast.LENGTH_SHORT).show();
                        break;
                    case 2:
                        currentselection = 2;
                        Toast.makeText(getApplicationContext(),
                                items[item], Toast.LENGTH_SHORT).show();
                        break;
                    }
                    mdialog.cancel();
                }
            });
    b1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            AlertDialog alert = builder.create();
            alert.show();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

Answer 1

Radio button does not preserve value. So you loose them after exiting. You can handle radio button scenario in combination with sharedpreferences.

After setting radio button add it to shared preferences like:

 private RadioButton mWifiDataButton = null;
 private RadioButton mWifiButton = null;

in onCreate() .. 

 mWifiDataButton = (RadioButton) findViewById(R.id.radio_wifi_data);
 mWifiDataButton.setOnClickListener(this);

 mWifiButton = (RadioButton) findViewById(R.id.radio_wifi_only);
 mWifiButton.setOnClickListener(this);



Editor ed = pref.edit();
ed.putBoolean("pref_radio_wifidata",mWifiDataButton.isChecked());
ed.putBoolean("pref_radio_wifi",mWifiButton.isChecked());

and next time retrieve the values like this:

mWifiDataButton.setChecked(pref.getBoolean("pref_radio_wifidata", true));
mWifiButton.setChecked(pref.getBoolean("pref_radio_wifi", false));



Then in onClick() handle it properly:

 @Override
    public void onClick(View v) {
        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        switch(v.getId()){


            case R.id.radio_wifi_data:
                pref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                boolean wifidataState = pref.getBoolean("pref_radio_wifidata", true);
                mWifiDataButton.setChecked(!wifidataState);
                mWifiButton.setChecked(wifidataState);
                Editor ed = pref.edit();
                ed.putBoolean("pref_radio_wifidata", !wifidataState);
                ed.putBoolean("pref_radio_wifi", wifidataState);
                ed.commit();
                break;
            case R.id.radio_wifi_only:
                pref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                boolean wifiState = pref.getBoolean("pref_radio_wifi", false);
                mWifiButton.setChecked(!wifiState);
                mWifiDataButton.setChecked(wifiState);
                Editor ed1 = pref.edit();
                ed1.putBoolean("pref_radio_wifi", !wifiState);
                ed1.putBoolean("pref_radio_wifidata", wifiState);
                ed1.commit();
                break;

ed.commit();