Android 源码阅读之建立3G网络流程

彩信是通过http协议发送数据的，因此，要先建立数据通路3G

发彩信时，会自动启动建立3G网络，不好跟代码，还是从设置中跟踪代码简单些

com.android.phone.Settings.java
onPreferenceTreeClick -> if (preference == mButtonDataEnabled) - ConnectivityManager.setMobileDataEnabled(true)
frameworks/base/core/java/android/net/ConnectivityManager.java
setMobileDataEnabled -> ConnectivityService.setMobileDataEnabled
frameworks/base/services/java/com/android/server/ConnectivityService.java
setMobileDataEnabled -> MyHandler.sendMessage[EVENT_SET_MOBILE_DATA] -> handleMessage EVENT_SET_MOBILE_DATA ->handleSetMobileData -> MobileDataStateTracker.reconnect()
frameworks/base/core/java/android/net/MobileDataStateTracker.java
reconnect -> setEnableApn -> CompositePhoneInterfaceManager.enableApnType
...
frameworks/base/telephony/java/com/android/internal/telephony/DataConnectionTracker.java
setEnabled:EVENT_ENABLE_NEW_APN -> handleMessage -> onEnableApn -> onEnableNewApn
frameworks/base/telephony/java/com/android/internal/telephony/gsm/GsmDataConnectionTracker.java
onEnableNewApn() -> cleanUpConnection -> DataConnection.disconnect[EVENT_DISCONNECT_DONE] -> onDisconnectDone -> trySetupData ->setupData -> DataConnection.connect EVENT_CONNECT -> CdmaDataConnection.onConnect -> phone.mCM.setupDataCall