Question

我一直在尝试以下方法让textview更新对SharedPreference所做的任何更改，但是我很难搞清楚我的下一步行动。任何人？：）

public class CallForwardActivity extends Activity implements
        OnSharedPreferenceChangeListener {

    SharedPreferences userInfo;
    Context context;
    UserController userControl;
    private static final String USERINFO_FILE = "StoredUserInfo";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.callforward);
        context = this;
        userInfo = this.getSharedPreferences(USERINFO_FILE, 0);
        userControl = new UserController(context);
        final TextView setActiveNumberTV = (TextView)
                                        findViewById(R.id.activeNumberTextView);
        setActiveNumberTV.setText(userControl.GetActiveNumber());
        final RelativeLayout showAvailablenumbers = (RelativeLayout)
                                        findViewById(R.id.showAvailableNumbers);
        showAvailablenumbers.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                Intent i = new Intent(getParent(),
                        AvailableNumbersActivity.class);
                SettingsActivityGroup parentActivity =
                                            (SettingsActivityGroup) getParent();
                parentActivity.ReplaceView(
                        "Show Available Numbers Activity", i);
            }
        });
    }

    public void onSharedPreferenceChanged(SharedPreferences arg0,
            String arg1) {
        final TextView setActiveNumberTV = (TextView)
                                        findViewById(R.id.activeNumberTextView);
        setActiveNumberTV.setText("...");
    }
}

Answer 1

您没有注册OnPreferenceChangedListener。在userInfo.registerOnSharedPreferenceChangeListener(this)中致电onCreate，它应该有效。

Answer 2

您不会在任何时候将sharedPreferenceChangedListener添加到您的sharedPreferences。

试试这个：

  userInfo.registerOnSharedPreferenceChangeListener(this);

在您实例化userInfo对象之后。

Answer 3

只是为了尝试...

public class CallForwardActivity extends Activity implements OnSharedPreferenceChangeListener
    {
    SharedPreferences userInfo;
    Context context;
    UserController userControl;
    private static final String USERINFO_FILE = "StoredUserInfo";
    private TextView setActiveNumberTV;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.callforward);
        context = this;
        userInfo = this.getSharedPreferences(USERINFO_FILE, 0);
            userInfo.registerOnSharedPreferenceChangeListener(this);
        userControl = new UserController(context);
        setActiveNumberTV = (TextView) findViewById(R.id.activeNumberTextView);
        setActiveNumberTV.setText(userControl.GetActiveNumber());       
        final RelativeLayout showAvailablenumbers = (RelativeLayout) findViewById(R.id.showAvailableNumbers); 
        showAvailablenumbers.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {
                Intent i = new Intent(getParent(), AvailableNumbersActivity.class);
                SettingsActivityGroup parentActivity = (SettingsActivityGroup)getParent();
                parentActivity.ReplaceView("Show Available Numbers Activity", i);
            }
        });
    }

    public void onSharedPreferenceChanged(SharedPreferences arg0, String arg1) 
    {
        setActiveNumberTV.setText(arg0.getString(arg1, "default"));
    }

}

每当SharedPreference更改时，如何更新TextView？

3 个答案: