android setPersistent

本文介绍了一个Activity的方法setPersistent,用于控制Activity是否为持久状态。默认情况下,Activity不是持久的;将其设置为true可以防止系统在资源紧张时终止该Activity及其进程。文章建议尽量避免使用此方法,因为它对系统资源管理有负面影响,并推荐使用服务组件作为替代方案。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

 

 

public void setPersistent (boolean isPersistent)


Since: API Level 1


Control whether this activity is required to be persistent. By default activities are not persistent; setting this to true willprevent the system from stopping this activity or its process when running low on resources.

设置activity是否长久有效,默认是不保持的。如果设置了这个标志,可以防止系统在低内存下kill或者stop这个activity或者他的process

You should avoid using this method, it has severe negative consequences on how well the system can manage its resources. A better approach is to implement an application service that you control with startService(Intent) and stopService(Intent).

 尽量避免使用这个方法,因为对server如何管理资源有负面影响。更好的解决办法是实现一个server 并通过startServerstopServer来控制。

 

Parameters

 

isPersistent

Control whether the current activity must be persistent, true if so, false for the normal behavior.

  

 

 

if (cursor != null) { final PreferenceGroup apnPrefList = (PreferenceGroup) findPreference("apn_list"); apnPrefList.removeAll(); final ArrayList<ApnPreference> apnList = new ArrayList<ApnPreference>(); final ArrayList<ApnPreference> mmsApnList = new ArrayList<ApnPreference>(); mSelectedKey = getSelectedApnKey(); cursor.moveToFirst(); while (!cursor.isAfterLast()) { final String name = cursor.getString(NAME_INDEX); final String apn = cursor.getString(APN_INDEX); final String key = cursor.getString(ID_INDEX); final String type = cursor.getString(TYPES_INDEX); final int edited = cursor.getInt(EDITED_INDEX); mMvnoType = cursor.getString(MVNO_TYPE_INDEX); mMvnoMatchData = cursor.getString(MVNO_MATCH_DATA_INDEX); final ApnPreference pref = new ApnPreference(getPrefContext()); pref.setKey(key); pref.setTitle(name); pref.setPersistent(false); pref.setOnPreferenceChangeListener(this); pref.setSubId(subId); if (mHidePresetApnDetails && edited == Telephony.Carriers.UNEDITED) { pref.setHideDetails(); } else { pref.setSummary(apn); } final boolean selectable = ((type == null) || type.contains(ApnSetting.TYPE_DEFAULT_STRING)); pref.setSelectable(selectable); if (selectable) { if ((mSelectedKey != null) && mSelectedKey.equals(key)) { pref.setChecked(); } apnList.add(pref); } else { mmsApnList.add(pref); } cursor.moveToNext(); } cursor.close(); for (Preference preference : apnList) { apnPrefList.addPreference(preference); } for (Preference preference : mmsApnList) { apnPrefList.addPreference(preference); } } }
07-14
评论 1
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值