前言

Andorid 代码里如何设置永不休眠时间，以及Settings 中增加超时时间选择

应用如何设置休眠时间

1. 应用需要 <uses-permission android:name="android.permission.WRITE_SETTINGS" /> 权限
2. 通过如下代码设置屏幕超时时间，注意传入的time 时间单位是毫秒

Settings.System.putInt(getContentResolver(),android.provider.Settings.System.SCREEN_OFF_TIMEOUT, time );

Settings 中如何设置的休眠时间?

Settings 是通过该TimeoutPreferenceController.java 控制的 packages/apps/Settings/src/com/android/settings/display/TimeoutPreferenceController.java

 @Override
public void updateState(Preference preference) {
    final TimeoutListPreference timeoutListPreference = (TimeoutListPreference) preference;
    final long currentTimeout = Settings.System.getLong(mContext.getContentResolver(),
            SCREEN_OFF_TIMEOUT, FALLBACK_SCREEN_TIMEOUT_VALUE);
    //<!–– add by lixh0815 for task299 20190418 begin
    if(isZh(mContext)){
        //代码1
        timeoutListPreference.setEntries(R.array.cn_screen_timeout_entries);
        timeoutListPreference.setEntryValues(R.array.cn_screen_timeout_values);
    }
    //代码2
    long timeoutValue = (currentTimeout == Integer.MAX_VALUE) ? -1 : currentTimeout;
    if(timeoutValue == -1 && !(isZh(mContext))){
        timeoutValue = FALLBACK_SCREEN_TIMEOUT_VALUE;
        Settings.System.putInt(mContext.getContentResolver(), SCREEN_OFF_TIMEOUT, FALLBACK_SCREEN_TIMEOUT_VALUE);
    }
    timeoutListPreference.setValue(String.valueOf(timeoutValue));
    // add by lixh0815 for task299 20190418 end ––>
    final DevicePolicyManager dpm =
            (DevicePolicyManager) mContext.getSystemService(Context.DEVICE_POLICY_SERVICE);
    if (dpm != null) {
        final RestrictedLockUtils.EnforcedAdmin admin =
                RestrictedLockUtils.checkIfMaximumTimeToLockIsSet(mContext);
        final long maxTimeout =
                dpm.getMaximumTimeToLock(null /* admin */, UserHandle.myUserId());
        timeoutListPreference.removeUnusableTimeouts(maxTimeout, admin);
    }
    updateTimeoutPreferenceDescription(timeoutListPreference, timeoutValue);

    EnforcedAdmin admin = RestrictedLockUtils.checkIfRestrictionEnforced(
                    mContext, UserManager.DISALLOW_CONFIG_SCREEN_TIMEOUT,
                    UserHandle.myUserId());
    if(admin != null) {
        timeoutListPreference.removeUnusableTimeouts(0/* disable all*/, admin);
    } else {
        MdmDisplayManager displayManager = MdmDisplayManager.get(mContext);
        if(displayManager != null) {
            try {
                timeoutListPreference.setEnabled(displayManager.isChangeScreenTimeoutAllowed());
            } catch(RuntimeException e) {}
        }
    }
}
//<!–– update by lixh0815 for task299 20190418 begin
@Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
    try {
        int timeoutValue = Integer.parseInt((String) newValue);
        //代码3
        int value = ( -1 == timeoutValue) ? Integer.MAX_VALUE : timeoutValue;
        Settings.System.putInt(mContext.getContentResolver(), SCREEN_OFF_TIMEOUT, value);
        updateTimeoutPreferenceDescription((TimeoutListPreference) preference, timeoutValue);
    } catch (NumberFormatException e) {
        Log.e(TAG, "could not persist screen timeout setting", e);
    }
    return true;
}

`packages/apps/Settings/res/values-zh-rTW/arrays.xml`
```xml
 <string-array name="cn_screen_timeout_entries">
    <item>"永不"</item>
    <item msgid="3342301044271143016">"15 秒"</item>
    <item msgid="8881760709354815449">"30 秒"</item>
    <item msgid="7589406073232279088">"1 分鐘"</item>
    <item msgid="7001195990902244174">"2 分鐘"</item>
    <item msgid="7489864775127957179">"5 分鐘"</item>
    <item msgid="2314124409517439288">"10 分鐘"</item>
    <item msgid="6864027152847611413">"30 分鐘"</item>
  </string-array>

packages/apps/Settings/res/values/arrays.xml

<string-array name="cn_screen_timeout_values" translatable="false">
        <item>-1</item>
        <!-- Do not translate. -->
        <item>15000</item>
        <!-- Do not translate. -->
        <item>30000</item>
        <!-- Do not translate. -->
        <item>60000</item>
        <!-- Do not translate. -->
        <item>120000</item>
        <!-- Do not translate. -->
        <item>300000</item>
        <!-- Do not translate. -->
        <item>600000</item>
        <!-- Do not translate. -->
        <item>1800000</item>
    </string-array>

Settings 中显示的选项从 cn_screen_timeout_entries中读取，对应值传入。从代码3可以看出在Settings应用中,值的单位是 毫秒，当选择永不休眠时传入 -1 值，而这个 -1值在真正的传入 Settings.System.putInt 中时就被修改为了Integer.MAX_VALUE;

如果要增加Settings 休眠时间可选要，则只要修改cn_screen_timeout_values、cn_screen_timeout_entries 这两个string-array 就行了。

应用中设置永不休眠

所以，如果应用要设置当前系统永不休眠，只要如下设置就行了

        Settings.System.putInt(getContentResolver(), android.provider.Settings.System.SCREEN_OFF_TIMEOUT, Integer.MAX_VALUE );