SharedPreferences

public class MainActivity extends Activity {
    private EditText et;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et = (EditText) findViewById(R.id.et);

    }
//存值
    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
        editor.putString("key", et.getText().toString());
        editor.commit();
        super.onPause();
    }
//读值
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        SharedPreferences sp = getPreferences(MODE_PRIVATE);
        et.setText(sp.getString("key", "default"));
        super.onResume();
    }

}