android 当系统存在多个Launcher时，如何设置开机自动进入默认的Launcher2

[DESCRIPTION]

当系统存在多个Launcher时，开机完成并解锁后，系统会弹出一个选择框让用户选择进入哪一个Launcher，如果不想选择，而是想直接进入某一个默认的Launcher，并且用户在设置->应用程序->管理应用程序->所有应用程序列表，找到之前设置的那个默认的Launcher，并且取消了默认值，可以重新弹出launcher选框。

[SOLUTION]

下面以设置Google Launcher2作为默认启动的Launcher为例，
其package name 为 com.android.launcher
launcher activity name 为 com.android.launcher2.Launcher

编辑packages/apps/Provision/src/com/android/DefaultActivity.java文件

       ......

// remove this activity from the package manager.

           PackageManager pm = getPackageManager();

           //add  start 

    String examplePackageName = "com.android.launcher"; //请修改为需要设置的 package name
    String exampleActivityName = "com.android.launcher2.Launcher"; //请修改为需要设置的 launcher activity name
    
           Intent intent=new Intent(Intent.ACTION_MAIN);
           intent.addCategory(Intent.CATEGORY_HOME);
           
           List resolveInfoList = pm.queryIntentActivities(intent, 0);
           if(resolveInfoList != null){
                    int size = resolveInfoList.size();
                    for(int j=0;j                              final ResolveInfo r = resolveInfoList.get(j);
                             if(!r.activityInfo.packageName.equals(examplePackageName)){
                                       resolveInfoList.remove(j);
                                       size -= 1;
                              }else
                              {
                                      j++;
                              }
                    }

                    ComponentName[] set = new ComponentName[size];
                    ComponentName defaultLauncher=new ComponentName(examplePackageName, exampleActivityName);

                    int defaultMatch=0;
                    for(int i=0;i                              final ResolveInfo resolveInfo = resolveInfoList.get(i);
                             Log.d(TAG, resolveInfo.toString());
                             set[i] = new ComponentName(resolveInfo.activityInfo.packageName,resolveInfo.activityInfo.name);
                             if(defaultLauncher.getClassName().equals(resolveInfo.activityInfo.name)){
                                       defaultMatch = resolveInfo.match;
                             }
                    }

                    Log.d(TAG,"defaultMatch="+Integer.toHexString(defaultMatch));

                    IntentFilter filter=new IntentFilter();
                    filter.addAction(Intent.ACTION_MAIN);
                    filter.addCategory(Intent.CATEGORY_HOME);
                    filter.addCategory(Intent.CATEGORY_DEFAULT);
                    
                    pm.clearPackagePreferredActivities(defaultLauncher.getPackageName());
                    pm.addPreferredActivity(filter, defaultMatch, set, defaultLauncher);
           }

           //add  end

 

        // remove this activity from the package manager.

        ComponentName name = new ComponentName(this, DefaultActivity.class);
  pm.setComponentEnabledSetting(name,
  PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
           PackageManager.DONT_KILL_APP);
       ......

 

然后修改packages/apps/Provision/AndroidManifest.xml文件，增加以下语句：

备注：
上面所添加的全部代码，一定要放在pm.setComponentEnabledSetting这两行语句之前，

特别说明：
如果以上步骤可以达到目的,请忽略以下描述
如果以上步骤不能达到目的
请再修改 packageManagerService.java (framework/base/java/com/android/server/pm/)
的 findPreferredActivity 方法
将此方法的比较靠后的一段代码添加如下语句
if (!pa.mPref.sameSet(query, priority)) {
 if(!(intent.getAction() != null 
 && intent.getAction().equals(intent.ACTION_MAIN) 
 && intent.getCategories()!=null 
 && intent.getCategories().contains(intent.CATEGORY_HOME))) //添加这行
 {  //添加这行
  Slog.i(TAG, "Result set changed, dropping preferred activity for "
                + intent + " type " + resolvedType);
  mSettings.mPreferredActivities.removeFilter(pa);
         return null;
 }  //添加这行
 Slog.i(TAG,"Result set not change, not drop preferred activity for special intent: "+intent);//添加这行
}

即可