設(shè)置中的Preferencescreen不僅可以作為設(shè)置界面顯示,，而且還能夠啟動(dòng)activity,，下面主要是對(duì)啟動(dòng)activity的介紹
1. Preferencescreen中啟動(dòng)activity
例如wireless_setting.xml中有如下片段

<PreferenceScreen xmlns:android="http://schemas./apk/res/android"
xmlns:settings="http://schemas./apk/res/com.seedshope.android">
    <PreferenceScreen
        android:key="wifi_settings"
        android:title="@string/wifi_settings"
        android:summary="@string/wifi_settings_summary" >
        <intent
            android:action="android.intent.action.MAIN"
            android:targetPackage="com.android.settings"
            android:targetClass="com.android.settings.wifi.WifiSettings" />
    </PreferenceScreen>
</PreferenceScreen>

其中com.android.settings是工程的包名,，com.android.settings.wifi.WifiSettings是要啟動(dòng)的類。
一般情況下,，這樣就ok了,，點(diǎn)擊對(duì)應(yīng)的Preference就能夠啟動(dòng)對(duì)應(yīng)的activity，然而僅僅這樣有時(shí)這樣,，并不一定能夠啟動(dòng)對(duì)應(yīng)的activity,，因?yàn)樗c回調(diào)函數(shù)onPreferenceTreeClick有關(guān)，有時(shí)候我們會(huì)重寫這個(gè)方法如：
    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
       if ( (preference == mAirplaneModePreference) &&
                (Boolean.parseBoolean(
                    SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE))) ) {
            // In ECM mode launch ECM app dialog
           startActivityForResult(
                new Intent(TelephonyIntents.ACTION_SHOW_NOTICE_ECM_BLOCK_OTHERS, null),
                REQUEST_CODE_EXIT_ECM);
            return true;
        }
        else {
            // Let the intents be launched by the Preference manager
            return false;
       }
    }
其中WirelessSetting.java中有如上函數(shù),當(dāng)返回值為true時(shí),你怎么點(diǎn)擊Preference都不會(huì)跳轉(zhuǎn)到activity的,，只有等到它的返回值為false的時(shí)候,，才可以正常跳轉(zhuǎn)，因?yàn)辄c(diǎn)擊某一個(gè)Preference的真正實(shí)現(xiàn)在Preference.java的performClick函數(shù)中如下：
void performClick(PreferenceScreen preferenceScreen) {
       
        if (!isEnabled()) {
            return;
        }
       
        onClick();
       
        if (mOnClickListener != null && mOnClickListener.onPreferenceClick(this)) {
            return;
        }
       
        PreferenceManager preferenceManager = getPreferenceManager();
        if (preferenceManager != null) {
            PreferenceManager.OnPreferenceTreeClickListener listener = preferenceManager
                    .getOnPreferenceTreeClickListener();
            if (preferenceScreen != null && listener != null
                    && listener.onPreferenceTreeClick(preferenceScreen, this)) {
                return;
            }
        }
       
        if (mIntent != null) {
            Context context = getContext();
            context.startActivity(mIntent);
        }
    }
當(dāng)點(diǎn)擊某個(gè)Preference時(shí)的調(diào)用流程是AdapterView.performItemClick－－》PreferenceScreen.onItemClick－－》Preference.performClick－－》PreferenceActivity.onPreferenceTreeClick,，當(dāng)onPreferenceTreeClick返回true的時(shí)候就直接return了，沒有走下面啟動(dòng)activity的地方了,，因此要使一個(gè)Preference能夠正常跳轉(zhuǎn)到另外一個(gè)activity有兩個(gè)條件,，一是xml里面是否設(shè)置正確，第二是調(diào)用該xml的java類是否在onPreferenceTreeClick這個(gè)函數(shù)需要返回false,。