开机默认此app作为launcher首次加载 ，就是设置这个apk为开机向导，并没有设置这个成默认launcher，若此应用是launcher应用那么按返回之后会提示让你选择哪一laucher前提是此应用内置并没有作为launcher应用，就可以用下面的方法。

开机自启，开机自动启动某个指定应用！!!!

方法一：（推荐）但是这个比较慢，开机已经进入系统了但是还有过好一会才会收到广播，它需要完成系统更新之后才接受到

vendor/mediatek/proprietary/packages/apps/SystemUI/ src/com/android/systemui/SystemUIApplication.java

在接受到开机广播的地方,执行跳转,这里是广播接受跳转，可以直接显式启动

IntentFilter bootCompletedFilter = new IntentFilter(Intent.ACTION_BOOT_COMPLETED);

            bootCompletedFilter.setPriority(IntentFilter.SYSTEM_HIGH_PRIORITY);

            registerReceiver(new BroadcastReceiver() {

下面增加执行操作

一：可以直接显式启动

Intent cIntent=new Intent();

        cIntent.setClassName("lte.trunk.tapp","lte.trunk.tapp.settings.AASSettingActivity");

        cIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                        android.util.Log.d("yantao", "cIntent="+cIntent);

        context.startActivity(cIntent);

二：用PackageManager().getLaunchIntentForPackage方法，可以不用传类名，适合不晓得具体那个activity先出来，只需要有一个包名就可以

Intent cIntent=new Intent();

                cIntent = context.getPackageManager().getLaunchIntentForPackage("lte.trunk.tapp");

                android.util.Log.d("yantao", "cIntent="+cIntent);

                if(cIntent != null){

                cIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

                    context.startActivity(cIntent);

                } else {

                    android.util.Log.d("yantao", "getLaunchIntentForPackage failed");

                }

O版本！o以上不起作用

frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java

在Home Activity 在上面的ActivityManagerService开启之后,会调用finishBooting()函数

在这个finishBooting中最后加入如下，这样可以开机指定应用直接进入这个应用，哪怕它是个launcher应用。就这一次首次加载，前面的判断可以不加

if (Settings.Global.getInt(mContext.getContentResolver(), Settings.Global.DEVICE_PROVISIONED, 0) != 1) {

+            Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.DEVICE_PROVISIONED, 1);

+            Settings.Secure.putInt(mContext.getContentResolver(), Settings.Secure.USER_SETUP_COMPLETE, 1);

+        }

+           Intent cIntent=new Intent();

+            cIntent = mContext.getPackageManager().getLaunchIntentForPackage("com.mcptt");

+            if(cIntent != null){

+                mContext.startActivity(cIntent);

+            } else {

+                android.util.Log.i("yantao", "getLaunchIntentForPackage failed" );+            }

+        //*/                     

上面就是设置这个apk为开机向导，ActivityManagerService中，由于开机向导只在系统第一次启动之前启动，所以开机向导关闭的时候需要将自己设置为不在启动。源码里finishBooting里面有句mAnrManager.writeEvent(AnrManager.EVENT_BOOT_COMPLETED);就是设置不再启动了。然后同时需要告诉系统开机向导已经完成了，需要写入如下属性到系统中(需要系统权限)

Settings.Global.putInt(getActivity().getContentResolver(), Settings.Global.DEVICE_PROVISIONED, 1);

Settings.Secure.putInt(getActivity().getContentResolver(), Settings.Secure.USER_SETUP_COMPLETE, 1);

然后在frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java里面修改别人写的按下电源键后锁死在launcher3了，判断如下，在case KeyEvent.KEYCODE_POWER: {这个case下 ，

else{

                        

-                        if(getCurrentActivityName(mContext).equals("com.android.launcher3.Launcher")) {

-                                if (down) {

-                                    interceptPowerKeyDown(event, interactive);

-                                } else {

-                                    interceptPowerKeyUp(event, interactive, canceled);

-                                }

-                        }else{

-                                if (down) {

-                                    Intent intent=new Intent();

-                                    intent.setClassName("com.android.launcher3","com.android.launcher3.Launcher");

-                                    mContext.startActivity(intent);

-                                }

-                        }

他这个意思是如果当前在launcher3，那么这个电源键正常使用，如果不在，那么就强制开启launcher3

我们只需要把这个回退到源码本来就可。就是电源键正常使用

if (down) {

                 interceptPowerKeyDown(event, interactive);

             } else {

                 interceptPowerKeyUp(event, interactive, canceled);

             }

             }

                break;

            }

上面是针对本身不是launcher的应用，如果本身就是launcher应用，那么就把它设置成默认launcher就可以

在frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java

在这个方法里startHomeActivityLocked,源码的最后加入

加入这个更改默认launcher的方法

final PackageManager mPm = mContext.getPackageManager();

       Intent homeIntent=new Intent();

       homeIntent.addCategory(Intent.CATEGORY_HOME);

       homeIntent.setAction(Intent.ACTION_MAIN);

       homeIntent.addCategory(Intent.CATEGORY_DEFAULT);

       ResolveInfo info = mPm.resolveActivity(homeIntent, PackageManager.MATCH_DEFAULT_ONLY);

       ComponentName DefaultLauncher=new ComponentName("afrizona.maxalerts.rotas","afrizona.maxalerts.rotas.MainActivity");

       ArrayList<ResolveInfo> homeActivities = new ArrayList<ResolveInfo>();

       ComponentName currentDefaultHome = mPm.getHomeActivities(homeActivities);

       ComponentName[]mHomeComponentSet = new ComponentName[homeActivities.size()];

       for (int i = 0; i < homeActivities.size(); i++) {

              final ResolveInfo candidate = homeActivities.get(i);

              Log.d(TAG,"homeActivitie: candidate = "+candidate);

              final ActivityInfo activityInfo= candidate.activityInfo;

              ComponentName activityName = new ComponentName(activityInfo.packageName, activityInfo.name);

              mHomeComponentSet[i] = activityName;

       }

       IntentFilter mHomeFilter = new IntentFilter(Intent.ACTION_MAIN);

       mHomeFilter.addCategory(Intent.CATEGORY_HOME);

       mHomeFilter.addCategory(Intent.CATEGORY_DEFAULT);

       List<ComponentName>Activities=new ArrayList();

       mPm.replacePreferredActivity(mHomeFilter, IntentFilter.MATCH_CATEGORY_EMPTY,mHomeComponentSet, DefaultLauncher);

完了别忘了把PhoneWindowManager里面别人强制电源键回launcher3的删了，如果有的话