动态添加EditTextPreference

Question

可以在EditTextPreference中动态地向PreferenceCategory添加PreferenceFragment吗？或者设置EditTextPreference的数量，然后创建相同数量的？我将非常感谢你的帮助

Answer 1

我使用一个帮助类来构建EditTextPreferences，我可以这样做：

Context context = getActivity();

PreferenceCategory statusCat = (PreferenceCategory) findPreference(context
            .getString(R.string.status_category));

EditTextPreference editTextPref = EditTextPrefBuilder.getBuilder(context)
                                 .setTitle("title")
                                 .setSummary("summary")
                                 .build();

statusCat.addPreference(editTextPref);

当然，您也可以在没有这个助手类的情况下创建EditTextPreference，我只是发现使用它时代码更容易阅读：

public class EditTextPrefBuilder {

    private final Context context;

    private String title;
    private String summary;
    private boolean enabled;

    public static EditTextPrefBuilder getBuilder(Context context) {
        return new EditTextPrefBuilder(context);
    }

    EditTextPreference ep = null;

    public EditTextPreference build() {
        ep = new EditTextPreference(context);
        ep.setTitle(title);
        ep.setSummary(summary);
        ep.setEnabled(enabled);
        return ep;

    }

    private EditTextPrefBuilder(Context context) {
        super();
        this.context = context;
        this.title = "";
        this.summary = "";
        this.enabled = false;
    }

    public EditTextPrefBuilder setTitle(String title) {
        this.title = title;
        return this;
    }

    public EditTextPrefBuilder setSummary(String summary) {
        this.summary = summary;
        return this;
    }

    public EditTextPrefBuilder setEnabled(boolean enabled) {
        this.enabled = enabled;
        return this;
    }

}

最后，一个PreferenceCategory示例显示了用于findPreference的键：

<PreferenceCategory
    android:key="@string/status_category"
    android:shouldDisableView="false"
    android:title="@string/module_status" >
    <SwitchPreference
        android:defaultValue="true"
        android:enabled="false"
        android:key="@string/key_module_activated_basis"
        android:switchTextOff="@string/deactive"
        android:switchTextOn="@string/active" />

    <CheckBoxPreference
        android:defaultValue="false"
        android:dependency="@string/key_module_activated_basis"
        android:enabled="false"
        android:key="@string/status_checkbox"
        android:selectable="false"
        android:summary="@string/please_wait"
        android:title="@string/checking" />
</PreferenceCategory>

编辑：

如果我正确理解了评论中的问题，您可以这样做：

@Override public void onStart() {
    // update initial values
    updateSummaries();
    super.onStart();
}

@Override
public void onResume() {
    // listen for when preference values change
    PreferenceManager.getDefaultSharedPreferences(context)
            .registerOnSharedPreferenceChangeListener(this);

    super.onResume();
}

@Override
public void onPause() {
    PreferenceManager.getDefaultSharedPreferences(context)
            .unregisterOnSharedPreferenceChangeListener(this);
    super.onPause();
}

@Override public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    // for simplicity update all summaries, could also inspect the key to only update that single Preference
    updateSummaries();
}

private void updateSummaries() {
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
    // update the summary of the EditText
    String editSummary = prefs.getString("key_for_edittext");
    (EditTextPreference)findPreference("key_for_edittext").setSummary(editSummary);
}

此示例设置摘要，当然，如果您想要这样做，也可以设置标题。