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我想知道是否有办法检查某人在共享首选项/设置屏幕上输入的内容以进行验证。用户触摸 Ip 输入选项，弹出一个 edittext 对话框，我试图将他们可以输入的内容限制为标准 IP 地址（即 0-255.0-255.0-255.0-255） 我查看过许多在线论坛并看到了使用 REGEX 和模式的不同事物的示例，这就是我到目前为止所拥有的，但绝对没有发生任何事情......有人可以帮助我吗？我将不胜感激！

    public class PrefsActivity extends PreferenceActivity implements
        OnSharedPreferenceChangeListener
{
    private EditTextPreference ipTextBox;
    private String whatWasTyped;
    private String previousText = "";
    private Editor myEditor;

    final Pattern IP_ADDRESS = Pattern
            .compile("^((1\\d{2}|2[0-4]\\d|25[0-5]|\\d?\\d)\\.){3}(?:1\\d{2}|2[0-4]\\d|25[0-5]|\\d?\\d)$");
    private String IP_FROM_PREFS = "ipAddressPref";
    SharedPreferences prefs;

    @Override
    /**
     * The onCreate method handles thing when starting this activity, 
     * mainly display the activity_settings.xml.
     */
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        // pattern for IP address validation
        addPreferencesFromResource(R.layout.activity_settings);

        // prefs.registerOnSharedPreferenceChangeListener(this);

        prefs = PreferenceManager.getDefaultSharedPreferences(this);
        // Get a reference to the preferences
        ipTextBox = (EditTextPreference) getPreferenceScreen().findPreference(
                IP_FROM_PREFS);

    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
            String key)
    {
        // check prefs value for IP.

        if (key.equals(IP_FROM_PREFS))
        {

            whatWasTyped = prefs.getString(IP_FROM_PREFS, "");
            CharSequence s = whatWasTyped;
            if (IP_ADDRESS.matcher(s).matches())
            {
                previousText = s.toString();
                            myEditor = prefs.edit();
                            myEditor.putString(IP_FROM_PREFS, previousText);
                myEditor.commit();

            } else
            {
                //if the format does not match, put up an error message
                            // or something.

            }
        }

    }

    @Override
    protected void onResume()
    {
        super.onResume();

        // Setup the initial values
        // mCheckBoxPreference.setSummary(sharedPreferences.getBoolean(key,
        // false) ? "Disable this setting" : "Enable this setting");
        // mListPreference.setSummary("Current value is " +
        // sharedPreferences.getValue(key, ""));

        // Set up a listener whenever a key changes
        getPreferenceScreen().getSharedPreferences()
                .registerOnSharedPreferenceChangeListener(this);
        previousText = prefs.getString(IP_FROM_PREFS, "");
    }

    @Override
    protected void onPause()
    {
        super.onPause();

        // Unregister the listener whenever a key changes
        getPreferenceScreen().getSharedPreferences()
                .unregisterOnSharedPreferenceChangeListener(this);
    }

}

由于这是在共享首选项屏幕上创建的，因此没有按钮 ID 等...

4

1 回答 1

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只是写

 whatWasTyped.replace(s, previousText);

不会将 previousText 分配给 SharedPreference 您需要将其分配回共享首选项并提交。

于 2012-08-03T19:46:34.957 回答