PackageManager,PackageInfo，ApplicationInfo ，ResolveInfo 的用法

首先得到PackageManager对象

PackageManager manager = getPackageManager();

ApplicationInfo通过解析AndroidManifest.xml的<application>标签中得到的，所以它能得到所有的app。

List< ApplicationInfo> appList =manager.getInstalledApplications(PackageManager.GET.UNINSTALLED_PAKAGES);

ResolveInfo通过解析< Intent-filter>标签得到有:

　　< actionandroid:name=”android.intent.action.MAIN”/>

　　< actionandroid:name=”android.intent.category.LAUNCHER”/>

Intent intent = new Intent(Intent.A CTION_MAIN,null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
List< ResolveInfo> appList = manager.queryIntentActivities(intent,0);

ResolveInfo获取图片、应用名、包名:

List<ResolveInfo> resolveList  = Utils.getShareApps(MessageSendActivity.this);

for(int i=0;i<resolveList.size();i++) {
ResolveInfo resolve = resolveList.get(i);
ShareItemInfo shareItem = new ShareItemInfo();
//set Icon
shareItem.setIcon(resolve.loadIcon(pManager));
//set Application Name
shareItem.setLabel(resolve.loadLabel(pManager).toString());
//set Package Name
shareItem.setPackageName(resolve.activityInfo.packageName);
//set Class Name
shareItem.setPackageName(resolve.activityInfo.name);
}

通过PackageManager可以获取手机端已安装的apk文件的信息:

List<PackageInfo> packageInfoList = packageManager.getInstalledPackages(0);

通过以上方法，可以得到手机中安装的所有应用程序，既包括了手动安装的apk包的信息，也包括了系统预装的应用软件的信息，要区分这两类软件可使用以下方法:
a.从packageInfoList获取的packageInfo，再通过packageInfo.applicationInfo获取applicationInfo。
b.判断(applicationInfo.flags& ApplicationInfo.FLAG_SYSTEM)的值，该值大于0时，表示获取的应用为系统预装的应用，反之则为手动安装的应用。

public static List<PackageInfo> getAllApps(Context context) {
List<PackageInfo> apps = new ArrayList<PackageInfo>();
PackageManager pManager = context.getPackageManager();
//获取手机内所有应用
List<PackageInfo> paklist = pManager.getInstalledPackages(0);
for (int i = 0; i < paklist.size(); i++) {
PackageInfo pak = (PackageInfo) paklist.get(i);
//判断是否为非系统预装的应用程序
if ((pak.applicationInfo.flags & pak.applicationInfo.FLAG_SYSTEM) <= 0) {
// customs applications
apps.add(pak);
}
}
return apps;
}

获取图片、应用名、包名:

PackageManager pManager = MessageSendActivity.this.getPackageManager();
List<PackageInfo> appList  = Utils.getAllApps(MessageSendActivity.this);
for(int i=0;i<appList.size();i++) {
PackageInfo pinfo = appList.get(i);
ShareItemInfo shareItem = new ShareItemInfo();
//set Icon
shareItem.setIcon(pManager.getApplicationIcon(pinfo.applicationInfo));
//set Application Name
shareItem.setLabel(pManager.getApplicationLabel(pinfo.applicationInfo).toString());
//set Package Name
shareItem.setPackageName(pinfo.applicationInfo.packageName);
}

获取支持分享的应用的代码：

public static List<ResolveInfo> getShareApps(Context context){
List<ResolveInfo> mApps = new ArrayList<ResolveInfo>();
Intent intent=new Intent(Intent.ACTION_SEND,null);
intent.addCategory(Intent.CATEGORY_DEFAULT);
intent.setType("text/plain");
PackageManager pManager = context.getPackageManager();
mApps = pManager.queryIntentActivities(intent,PackageManager.COMPONENT_ENABLED_STATE_DEFAULT);
return mApps;
}