一、拨号流程总结
DialpadFragment提供用户拨号的交互界面 CallIntentBuilder创建拨号请求的intent对象 TelecomManager继续传递拨号请求intent对象 
二、ITelecomService接收拨号请求服务
/packages/services/Telecomm/src/com/android/server/telecom这个代码库编译出来就是Telecom.apk Android应用程序，后面统一称为Telecom应用
<service android:name=".components.TelecomService"
android:singleUser="true"
android:process="system">
<intent-filter>
<action android:name="android.telecom.ITelecomService" />
</intent-filter>
</service>
指定进程为system,也就是这个服务将会运行在system_server系统，唯一的action为android.telecom.ITelecomService.
❝注意：Dialer应用的com.android.dialer进程提供用户拨号界面并且响应用户的拨号请求，把拨号请求包装成action为Intent.ACTION_CALL的intent对象，通过调用ITelecomService提供的placeCall接口，将拨号请求intent发送给了Telelcom应用（system_server进程），完成了第一次跨进程的服务调用。
❞
看一下TelecomServiceImpl.java文件中的placeCall方法
public void placeCall(Uri handle, Bundle extras, String callingPackage) {
try {
Log.startSession("TSI.pC");
enforceCallingPackage(callingPackage);
PhoneAccountHandle phoneAccountHandle = null;
if (extras != null) {
phoneAccountHandle = extras.getParcelable(
TelecomManager.EXTRA_PHONE_ACCOUNT_HANDLE);
if (extras.containsKey(TelecomManager.EXTRA_IS_HANDOVER)) {
// This extra is for Telecom use only so should never be passed in.
extras.remove(TelecomManager.EXTRA_IS_HANDOVER);
}
}
boolean isSelfManaged = phoneAccountHandle != null &&
isSelfManagedConnectionService(phoneAccountHandle);
if (isSelfManaged) {
mContext.enforceCallingOrSelfPermission(Manifest.permission.MANAGE_OWN_CALLS,
"Self-managed ConnectionServices require MANAGE_OWN_CALLS permission.");
if (!callingPackage.equals(
phoneAccountHandle.getComponentName().getPackageName())
&& !canCallPhone(callingPackage,
"CALL_PHONE permission required to place calls.")) {
// The caller is not allowed to place calls, so we want to ensure that it
// can only place calls through itself.
throw new SecurityException("Self-managed ConnectionServices can only "
+ "place calls through their own ConnectionService.");
}
} else if (!canCallPhone(callingPackage, "placeCall")) {
throw new SecurityException("Package " + callingPackage
+ " is not allowed to place phone calls");
}
三、源码：
https://github.com/ruigege66/Android/tree/master/ContactsTestCSDN：https://blog.csdn.net/weixin_44630050 博客园：https://www.cnblogs.com/ruigege0000/ 欢迎关注微信公众号：傅里叶变换，个人账号，仅用于技术交流
