干净的解决方案，过滤成功的系统应用程序

这个解决方案背后的思想是，每个系统应用程序的主活动都没有一个自定义的活动图标。这个方法给了我一个很好的结果:

 public static Set<PackageInfo> getInstalledApps(Context ctx) {
    final PackageManager packageManager = ctx.getPackageManager();

    final List<PackageInfo> allInstalledPackages = packageManager.getInstalledPackages(PackageManager.GET_META_DATA);
    final Set<PackageInfo> filteredPackages = new HashSet();

    Drawable defaultActivityIcon = packageManager.getDefaultActivityIcon();

    for(PackageInfo each : allInstalledPackages) {
        if(ctx.getPackageName().equals(each.packageName)) {
            continue;  // skip own app
        }

        try {
            // add only apps with application icon
            Intent intentOfStartActivity = packageManager.getLaunchIntentForPackage(each.packageName);
            if(intentOfStartActivity == null)
                continue;

            Drawable applicationIcon = packageManager.getActivityIcon(intentOfStartActivity);
            if(applicationIcon != null && !defaultActivityIcon.equals(applicationIcon)) {
                filteredPackages.add(each);
            }
        } catch (PackageManager.NameNotFoundException e) {
            Log.i("MyTag", "Unknown package name " + each.packageName);
        }
    }

    return filteredPackages;
}

下面是获取Android上安装的活动/应用程序列表的代码:

Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
List<ResolveInfo> pkgAppsList = context.getPackageManager().queryIntentActivities( mainIntent, 0);

您将在ResolveInfo中获得启动应用程序所需的所有数据。你可以在这里检查ResolveInfo javadoc。

下面是使用PackageManager的一种更简洁的方式

final PackageManager pm = getPackageManager();
//get a list of installed apps.
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);

for (ApplicationInfo packageInfo : packages) {
    Log.d(TAG, "Installed package :" + packageInfo.packageName);
    Log.d(TAG, "Source dir : " + packageInfo.sourceDir);
    Log.d(TAG, "Launch Activity :" + pm.getLaunchIntentForPackage(packageInfo.packageName)); 
}
// the getLaunchIntentForPackage returns an intent that you can use with startActivity() 

更多信息请点击这里http://qtcstation.com/2011/02/how-to-launch-another-app-from-your-app/

context.getPackageManager () .getInstalledApplications (PackageManager.GET_META_DATA); 应该返回所有已安装应用程序的列表，但在android 11中，它只返回系统应用程序的列表。要获得所有应用程序(系统+用户)的列表，我们需要为应用程序提供额外的权限

< uses-permission android: name = " android.permission.QUERY_ALL_PACKAGES " / >

你可以通过下面的代码找到Android设备中已安装的应用程序列表，“packageInfo”包含已安装的应用程序信息 在设备。我们可以为安装的应用程序检索Intent packageinfo对象可以使用startactivity(intent)来启动 应用程序。这取决于你如何组织UI或Listview 或显示数据表格。基于位置的点击事件，你可以检索意图 对象和启动活动意图。

final PackageManager pm = getPackageManager();

List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);


for (ApplicationInfo packageInfo : packages) 

{
 if(pm.getLaunchIntentForPackage(packageInfo.packageName)!= null &&   

                   !pm.getLaunchIntentForPackage(packageInfo.packageName).equals(""))


{

    System.out.println("Package Name :" + packageInfo.packageName);

    System.out.println("Launch Intent For Package :"   +  
                  pm.getLaunchIntentForPackage(packageInfo.packageName));

    System.out.println("Application Label :"   + pm.getApplicationLabel(packageInfo));

    System.out.println("Application Label :"   + 
                           pm.getApplicationIcon(packageInfo.packageName).toString());

    System.out.println("i : "+i);

    /*if(i==2)

    {
         startActivity(pm.getLaunchIntentForPackage(packageInfo.packageName));

     break;

    }*/

    i++;

}
}

干净的解决方案，过滤成功的系统应用程序

这个解决方案背后的思想是，每个系统应用程序的主活动都没有一个自定义的活动图标。这个方法给了我一个很好的结果:

 public static Set<PackageInfo> getInstalledApps(Context ctx) {
    final PackageManager packageManager = ctx.getPackageManager();

    final List<PackageInfo> allInstalledPackages = packageManager.getInstalledPackages(PackageManager.GET_META_DATA);
    final Set<PackageInfo> filteredPackages = new HashSet();

    Drawable defaultActivityIcon = packageManager.getDefaultActivityIcon();

    for(PackageInfo each : allInstalledPackages) {
        if(ctx.getPackageName().equals(each.packageName)) {
            continue;  // skip own app
        }

        try {
            // add only apps with application icon
            Intent intentOfStartActivity = packageManager.getLaunchIntentForPackage(each.packageName);
            if(intentOfStartActivity == null)
                continue;

            Drawable applicationIcon = packageManager.getActivityIcon(intentOfStartActivity);
            if(applicationIcon != null && !defaultActivityIcon.equals(applicationIcon)) {
                filteredPackages.add(each);
            }
        } catch (PackageManager.NameNotFoundException e) {
            Log.i("MyTag", "Unknown package name " + each.packageName);
        }
    }

    return filteredPackages;
}