Question

在我的主要活动中，我正在检查学生是否已将他们的ID存储在共享偏好中在onResume中，我检查字符串是否为空，如果是，则启动对话框

 private void showNoStudentIdDialog() {
    LayoutInflater inflater = LayoutInflater.from(this);
    View view = inflater.inflate(R.layout.dialog_no_id, null);

    AlertDialog.Builder builder = new AlertDialog.Builder(this);

    builder.setView(view).setTitle(getString(R.string.no_id_dialog_title));
    builder.setCancelable(false);
    builder.setPositiveButton(getString(R.string.ok), new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();

            openSettingsDetail();
        }
    });
    builder.create().show();
}

openSettingDetail

public boolean openSettingsDetail() {
    Intent settingsIntent = new Intent(this, SettingsActivity.class);
    startActivity(settingsIntent);
    return true;
}

意图正确启动我的SettingsActivty并加载正确的首选项。但是，我仍然需要手动触摸ID首选项以启动它的对话框。我可以在启动意图时从MainActivity以编程方式实现此触摸/单击吗？

SettingsActivity

public class SettingsActivity extends AppCompatPreferenceActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setupActionBar();
    addPreferencesFromResource(R.xml.pref_general);

    bindPreferenceSummaryToValue(findPreference(getString(R.string.student_id_key)));
    bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_timetable_key)));

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == android.R.id.home) {
        this.finish();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * Set up the {@link android.app.ActionBar}, if the API is available.
 */
private void setupActionBar() {
    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null) {
        // Show the Up button in the action bar.
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setDisplayShowHomeEnabled(true);
        actionBar.setDisplayShowTitleEnabled(false);
        actionBar.setIcon(R.drawable.settings);
    }
}


/**
 * {@inheritDoc}
 */
@Override
public boolean onIsMultiPane() {
    return isXLargeTablet(this);
}

/**
 * Helper method to determine if the device has an extra-large screen. For
 * example, 10" tablets are extra-large.
 */
private static boolean isXLargeTablet(Context context) {
    return (context.getResources().getConfiguration().screenLayout
            & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
}


/**
 * A preference value change listener that updates the preference's summary
 * to reflect its new value.
 */
private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
    @Override
    public boolean onPreferenceChange(Preference preference, Object value) {
        String stringValue = value.toString();

        if (preference.getKey().equals(preference.getContext().getString(R.string.student_id_key))) {
            setPreferenceSummary(preference, stringValue);
        } else if (preference instanceof ListPreference) {
            // For list preferences, look up the correct display value in
            // the preference's 'entries' list.
            ListPreference listPreference = (ListPreference) preference;
            int index = listPreference.findIndexOfValue(stringValue);

            // Set the summary to reflect the new value.
            preference.setSummary(
                    index >= 0
                            ? listPreference.getEntries()[index]
                            : null);

        } else if (preference instanceof RingtonePreference) {
            // For ringtone preferences, look up the correct display value
            // using RingtoneManager.
            if (TextUtils.isEmpty(stringValue)) {
                // Empty values correspond to 'silent' (no ringtone).
                preference.setSummary(R.string.pref_ringtone_silent);

            } else {
                Ringtone ringtone = RingtoneManager.getRingtone(
                        preference.getContext(), Uri.parse(stringValue));

                if (ringtone == null) {
                    // Clear the summary if there was a lookup error.
                    preference.setSummary(null);
                } else {
                    // Set the summary to reflect the new ringtone display
                    // name.
                    String name = ringtone.getTitle(preference.getContext());
                    preference.setSummary(name);
                }
            }

        } else {
            // For all other preferences, set the summary to the value's
            // simple string representation.
            preference.setSummary(stringValue);
        }
        return true;
    }
};

private static void setPreferenceSummary(Preference preference, Object value) {
    String stringValue = value.toString();
    String key = preference.getKey();

    if (preference instanceof ListPreference) {
        // For list preferences, look up the correct display value in
        // the preference's 'entries' list (since they have separate labels/values).
        ListPreference listPreference = (ListPreference) preference;
        int prefIndex = listPreference.findIndexOfValue(stringValue);
        if (prefIndex >= 0) {
            preference.setSummary(listPreference.getEntries()[prefIndex]);
        }
    } else if (key.equals(preference.getContext().getString(R.string.student_id_key))) {
        @TimetableSyncAdapter.ServerStatus int status = Utility.getServerStatus(preference.getContext());
        switch (status) {
            case TimetableSyncAdapter.SERVER_STATUS_OK:
                preference.setSummary(stringValue);
                break;
            case TimetableSyncAdapter.SERVER_STATUS_UNKNOWN:
                preference.setSummary(preference.getContext().getString(R.string.pref_student_id_unknown_description, value.toString()));
                break;
            case TimetableSyncAdapter.SERVER_STATUS_ID_INVALID:
                preference.setSummary(preference.getContext().getString(R.string.pref_student_id_invalid_id, value.toString()));
                break;
            default:
                // Note --- if the server is down we still assume the value
                // is valid
                preference.setSummary(stringValue);
        }
    } else {
        // For other preferences, set the summary to the value's simple string representation.
        preference.setSummary(stringValue);
    }

}

/**
 * Binds a preference's summary to its value. More specifically, when the
 * preference's value is changed, its summary (line of text below the
 * preference title) is updated to reflect the value. The summary is also
 * immediately updated upon calling this method. The exact display format is
 * dependent on the type of preference.
 *
 * @see #sBindPreferenceSummaryToValueListener
 */
private static void bindPreferenceSummaryToValue(Preference preference) {
    // Set the listener to watch for value changes.
    preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);

    // Trigger the listener immediately with the preference's
    // current value.
    sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
            PreferenceManager
                    .getDefaultSharedPreferences(preference.getContext())
                    .getString(preference.getKey(), ""));
}

/**
 * This method stops fragment injection in malicious applications.
 * Make sure to deny any unknown fragments here.
 */
protected boolean isValidFragment(String fragmentName) {
    return PreferenceFragment.class.getName().equals(fragmentName)
            || GeneralPreferenceFragment.class.getName().equals(fragmentName)
            || DataSyncPreferenceFragment.class.getName().equals(fragmentName)
            || NotificationPreferenceFragment.class.getName().equals(fragmentName);
}

/**
 * This fragment shows general preferences only. It is used when the
 * activity is showing a two-pane settings UI.
 */
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class GeneralPreferenceFragment extends PreferenceFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.pref_general);
        setHasOptionsMenu(true);



        // Bind the summaries of EditText/List/Dialog/Ringtone preferences
        // to their values. When their values change, their summaries are
        // updated to reflect the new value, per the Android Design
        // guidelines.

        bindPreferenceSummaryToValue(findPreference(getString(R.string.student_id_key)));
        bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_timetable_key)));
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == android.R.id.home) {
            getActivity().finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

}


/**
 * This fragment shows notification preferences only. It is used when the
 * activity is showing a two-pane settings UI.
 */
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class NotificationPreferenceFragment extends PreferenceFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.pref_notification);
        setHasOptionsMenu(true);

        // Bind the summaries of EditText/List/Dialog/Ringtone preferences
        // to their values. When their values change, their summaries are
        // updated to reflect the new value, per the Android Design
        // guidelines.
        bindPreferenceSummaryToValue(findPreference("notifications_new_message_ringtone"));
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == android.R.id.home) {
            getActivity().finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

/**
 * This fragment shows data and sync preferences only. It is used when the
 * activity is showing a two-pane settings UI.
 */
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class DataSyncPreferenceFragment extends PreferenceFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.pref_data_sync);
        setHasOptionsMenu(true);

        // Bind the summaries of EditText/List/Dialog/Ringtone preferences
        // to their values. When their values change, their summaries are
        // updated to reflect the new value, per the Android Design
        // guidelines.
        bindPreferenceSummaryToValue(findPreference("sync_frequency"));
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == android.R.id.home) {
            getActivity().finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

}

pref_general.xml

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res/com.mcgowan.timetable.itsligotimetables">


<com.mcgowan.timetable.itsligotimetables.StudentIdEditTextPreference
    android:capitalize="words"
    android:defaultValue="@string/student_id_default"
    android:hint="@string/student_id_hint"
    android:inputType="textCapWords"
    android:key="@string/student_id_key"
    android:maxLength="9"
    custom:minLength="9"
    android:maxLines="1"
    android:selectAllOnFocus="true"
    android:singleLine="true"
    android:title="@string/pref_title_display_name" />


<ListPreference
    android:defaultValue="@string/pref_timetable_type_classes"
    android:entries="@array/timetable_type_list_titles"
    android:entryValues="@array/timetable_type_list_values"
    android:key="@string/pref_timetable_key"
    android:title="@string/pref_title_timetable_type" />

首先显示此对话框，然后启动意图

意图启动以下屏幕：

我必须点击学生ID首选项才能启动以下

我想跳过第二张图片中的步骤，并以编程

以编程方式启动最后一张图片

Answer 1

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setupActionBar();
    addPreferencesFromResource(R.xml.pref_general);

    bindPreferenceSummaryToValue(findPreference(getString(R.string.student_id_key)));
bindPreferenceSummaryToValue(findPreference(getString(R.string.pref_timetable_key)));

  if (<student ID is empty)) {
    showNoStudentIdDialog();
  }

}

是的，我知道，但我真的很困惑你在问什么。如果你想显示对话框，只需调用方法在任何地方和任何条件下显示它......

从Activity中启动PreferenceDialog

1 个答案: