系统存在多个Launcher时，如何设置开机自动进入默认的Launch

系统存在多个Launcher时，如何设置开机自动进入默认的Launcher

[FAQ]当系统存在多个Launcher时，如何设置开机自动进入默认的Launcher？
[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<ResolveInfo> resolveInfoList =
pm.queryIntentActivities(intent, 0);
          if(resolveInfoList != null){
                   int size = resolveInfoList.size();
                   for(int j=0;j<size;){
                            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<size;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(defaultLaunchr.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：
<uses-permission
android:name=”android.permission.SET_PREFERRED_APPLICATIONS” />
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/services/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
{  //添加这行
 Slog.i(TAG, “Result set changed, dropping preferred activity
               + intent + ” type ” + resolvedType);
 mSettings.mPreferredActivities.removeFilter(pa);
        return null;
}  //添加这行
Slog.i(TAG,”Result set not change, not drop preferred activity
special intent: “+intent);//添加这行
}
即可