藍芽耳機Priority設定流程

當藍芽耳機配對成功後，會傳送乙個bonding_state_change的訊息，在bondstatemachine狀態機裡會對這個訊息進行處理，呼叫setprofilepriorty(dev)函式對當前的耳機進行優先順序的設定，

把以前的設定優先順序順序hid、a2dp、headset改為headset、a2dp、hid，請看這個函式修改後的具體code：

private void setprofilepriorty(bluetoothdevice device){

hidservice hidservice = hidservice.gethidservice();

a2dpservice a2dpservice = a2dpservice.geta2dpservice();

headsetservice headsetservice = headsetservice.getheadsetservice();

if ((headsetservice != null) &&

(headsetservice.getpriority(device)== bluetoothprofile.priority_undefined)){

headsetservice.setpriority(device,bluetoothprofile.priority_on);

if ((a2dpservice != null) &&

(a2dpservice.getpriority(device) ==bluetoothprofile.priority_undefined)){

a2dpservice.setpriority(device,bluetoothprofile.priority_on);

if((hidservice != null) &&

(hidservice.getpriority(device) ==bluetoothprofile.priority_undefined)){

hidservice.setpriority(device,bluetoothprofile.priority_on);

會把當前耳機的headset profile 和a2dp profile的優先順序設定為priority_on。

當藍芽耳機連線成功時，processprofilestatechanged函式會呼叫 setprofileautoconnectionpriority(device,profileid)函式設定優先順序，看修改後這個函式的具體code：

void setprofileautoconnectionpriority(bluetoothdevice device, int profileid){

headsetservice hsservice = headsetservice.getheadsetservice();

a2dpservice a2dpservice =a2dpservice.geta2dpservice();

if ((hsservice != null) &&

(bluetoothprofile.priority_auto_connect !=hsservice.getpriority(device))){

adjustotherheadsetpriorities(hsservice,device);

hsservice.setpriority(device,bluetoothprofile.priority_auto_connect);

if ((a2dpservice != null)&&

(bluetoothprofile.priority_auto_connect != a2dpservice.getpriority(device))){

adjustothersinkpriorities(a2dpservice, device);

a2dpservice.setpriority(device,bluetoothprofile.priority_auto_connect);

會把當前耳機的headset和a2dp的profile優先順序都設定為priority_auto_connect，同時會把其他的耳機裝置的優先順序設為priority_on，保證耳機自動連線優先順序的裝置只有乙個。

藍芽耳機自動連線過程：

當藍芽開啟時，如果有配對的藍芽耳機存在，就會根據它的優先順序，判斷是否進行自動連線。如果優先順序為priority_auto_connect，該耳機就會自動進行連線。