android 设置默认launcher 附上代码-优快云博客

本文链接：https://blog.youkuaiyun.com/seableble/article/details/103173832

本文详细阐述了系统初始化过程中的关键步骤，包括如何通过ActivityManagerService和ActivityStack实现homeactivity的启动，并介绍如何在系统启动时设置默认的Launcher应用。

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当系统初始化完毕后会进入homeactivity：
具体代码流程：
ActivityManagerService.java -->
public void systemReady(final Runnable goingCallback) {
...
mMainStack.resumeTopActivityLocked(null);
...
}

ActivityStack.java
final boolean resumeTopActivityLocked(ActivityRecord prev) {
        return resumeTopActivityLocked(prev, null);
    }

final boolean resumeTopActivityLocked(ActivityRecord prev, Bundle options) {
...
return mService.startHomeActivityLocked(mCurrentUser); //开始启动homeactivity了，
...
}

然后我们可以在最开始加入一个自己写的接口，来设置默认launcher：
boolean startHomeActivityLocked(int userId) {
   ...
   setDefaultLauncher();
   ...

}

[java] view plain copy

private void setDefaultLauncher() {
// get default component
String packageName = "com.android.launcher";//默认launcher包名
String className = "com.android.launcher2.Launcher";////默认launcher入口
Slog.i(TAG, "defautl packageName = " + packageName + ", default className = " + className);
if ((packageName != null && packageName.trim().length() > 1) && (className != null && className.trim().length() > 0)) {
boolean firstLaunch = SystemProperties.getBoolean("persist.sys.sw.firstLaunch", true); //只做一次可以注意这几个变量firstLaunch mFirstLaunch
Slog.d(TAG, "firstLaunch = " + firstLaunch);
if(firstLaunch){
mFirstLaunch = true;
// do this only for the first boot
SystemProperties.set("persist.sys.sw.firstLaunch", "false");
}
Slog.d(TAG, "firstLaunch = " + firstLaunch);
if(mFirstLaunch){
IPackageManager pm = ActivityThread.getPackageManager();
//清除当前默认launcher
ArrayList<IntentFilter> intentList = new ArrayList<IntentFilter>();
ArrayList<ComponentName> cnList = new ArrayList<ComponentName>();
mContext.getPackageManager().getPreferredActivities(intentList, cnList, null);
IntentFilter dhIF;
for(int i = 0; i < cnList.size(); i++)
{
dhIF = intentList.get(i);
if(dhIF.hasAction(Intent.ACTION_MAIN) &&
dhIF.hasCategory(Intent.CATEGORY_HOME))
{
mContext.getPackageManager().clearPackagePreferredActivities(cnList.get(i).getPackageName());
}
}
//获取所有launcher activity
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
List<ResolveInfo> list = new ArrayList<ResolveInfo>();
try
{
list = pm.queryIntentActivities(intent,
intent.resolveTypeIfNeeded(mContext.getContentResolver()),
PackageManager.MATCH_DEFAULT_ONLY,UserHandle.getCallingUserId());
}catch (RemoteException e) {
throw new RuntimeException("Package manager has died", e);
}
// get all components and the best match
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_MAIN);
filter.addCategory(Intent.CATEGORY_HOME);
filter.addCategory(Intent.CATEGORY_DEFAULT);
final int N = list.size();
Slog.d(TAG, "N:::::hyhyhyhy:::: = " + N);
ComponentName[] set = new ComponentName[N];
int bestMatch = 0;
for (int i = 0; i < N; i++)
{
ResolveInfo r = list.get(i);
set[i] = new ComponentName(r.activityInfo.packageName,
r.activityInfo.name);
Slog.d(TAG, "r.activityInfo.packageName:::::hyhyhyhy:::: = " + r.activityInfo.packageName);
Slog.d(TAG, "r.activityInfo.name:::::hyhyhyhy:::: = " + r.activityInfo.name);
if (r.match > bestMatch) bestMatch = r.match;
}
//设置默认launcher
ComponentName launcher = new ComponentName(packageName, className);
try
{
pm.addPreferredActivity(filter, bestMatch, set, launcher,UserHandle.getCallingUserId());
} catch (RemoteException e) {
throw new RuntimeException("Package manager has died", e);
}
}
}
}