主要利用兩個(gè)信息類：PackageInfo、ApplicationInfo

一、獲取應(yīng)用PackageInfo信息

以下packageManager都用這個(gè)表示

PackageManager packageManager = context.getPackageManager()；

獲取方式

==獲取不同信息主要是傳入不同的flag值==

//第一個(gè)參數(shù)傳入應(yīng)用包名，
//第二個(gè)參數(shù)是一個(gè)flag表示你想要獲取哪些信息，比如下例的activity信息及activity標(biāo)簽下的metadata信息
PackageInfo packageInfo = packageManager.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES | PackageManager.GET_META_DATA)；

具體信息獲取

1、權(quán)限信息(AndroidManifest中<uses-permission/>標(biāo)簽中信息列表)

String[] permisions = packageManager.getPackageInfo(packageName, PackageManager.GET_PERMISSIONS).requestedPermissions；

2、版本信息

PackageInfo packageInfo = packageManager.getPackageInfo(packageName, 0)；
String versionName = packageInfo.versionName；
int versionCode = packageInfo.versionCode；

3、其他信息

比如sharedUserId、packageName等等

二、獲取ApplicationInfo信息

獲取方式

//由上述packageInfo中獲取得到
ApplicationInfo applicationInfo = packageInfo.applicationInfo；

具體信息獲取

1、應(yīng)用名稱

String appName = (String) applicationInfo.loadLabel(packageManager);

2、應(yīng)用圖標(biāo)

Drawable appIcon = applicationInfo.loadIcon(packageManager)；

3、其他信息

比如taskAffinity、processName、theme等

三、獲取組件信息(ActivityInfo、ServiceInfo、ProviderInfo)

ActvitityInfo

==Activity或者BroadcastReceiver信息都是通過ActivityInfo獲取的==

獲取方式

//flag值必須包含PackageManager.GET_ACTIVITIES，如果還要獲取其他信息如metadata則增加一個(gè)flag值PackageManager.GET_META_DATA
PackageInfo packageInfo = packageManager.getPackageInfo(packageName,PackageManager.GET_ACTIVITIES);
//activity信息
ActivityInfo[] activities = packageInfo.activities;

//flag值必須包含PackageManager.GET_RECEIVERS，如果還要獲取其他信息如metadata則增加一個(gè)flag值PackageManager.GET_META_DATA
PackageInfo packageInfo = packageManager.getPackageInfo(packageName,PackageManager.GET_RECEIVERS);
//broadcastreceiver信息
ActivityInfo[] receivers = packageInfo.receivers

具體信息獲取

1、activity全路徑

String activityClassName = activityInfo.name;

2、其他信息

比如theme、launchMode、taskAffinity等

ServiceInfo

Service信息通過ServiceInfo獲取

獲取方式

//flag值必須包含PackageManager.GET_SERVICES，如果還要獲取其他信息如metadata則增加一個(gè)flag值PackageManager.GET_META_DATA
PackageInfo packageInfo = packageManager.getPackageInfo(packageName,PackageManager.GET_SERVICES);
ServiceInfo[] services = packageInfo.services;

具體信息獲取

比如flags、permission

ProviderInfo

ContentProvider信息通過ProviderInfo獲取

獲取方式

//flag值必須包含PackageManager.GET_PROVIDERS，如果還要獲取其他信息如metadata則增加一個(gè)flag值PackageManager.GET_META_DATA
PackageInfo packageInfo = packageManager.getPackageInfo(packageName,PackageManager.GET_PROVIDERS);
ServiceInfo[] services = packageInfo.services;

具體信息獲取

比如authority、readPermission、writePermission等

四、使用實(shí)例

1、根據(jù)包名獲取應(yīng)用信息

//首先獲取packageManager
PackageManager packageManager = context.getPackageManager();
//獲取packageInfo信息
PackageInfo packageInfo = packageManager.getPackageInfo(packageName, 0);
//獲取應(yīng)用版本號(hào)
int versionCode = packageInfo.versionCode;
//獲取應(yīng)用版本名
String versionName = packageInfo.versionName;
//獲取應(yīng)用名稱
String appName = (String) packageInfo.applicationInfo.loadLabel(packageManager);
//獲取應(yīng)用圖標(biāo)
Drawable appIcon = packageInfo.applicationInfo.loadIcon(packageManager)

//<application/>標(biāo)簽下metadata獲取
ApplicationInfo applicationInfo = packageManager.getApplicationInfo(packageName, PackageManager.GET_META_DATA);
Bundle metadata = applicationInfo.metaData;//然后通過改bundle獲取相應(yīng)值，用法見bundle

//<activity/>標(biāo)簽下metadata獲取(其他service\receiver\provider同理，切換flag即可)
//入口信息獲取
PackageInfo packageInfo = packageManager.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES | PackageManager.GET_META_DATA);
ActivityInfo[] activityInfos = packageInfo.activities;
for (ActivityInfo activityInfo : activityInfos) {
    Bundle metadata = activityInfo.metaData;//然后通過改bundle獲取相應(yīng)值，用法
見bundle
    String activityClassName = activityInfo.name;
}

2、擴(kuò)展（直接獲取未安裝apk信息）

PackageManager packageManager = context.getPackageManager();
//apkPath傳入apk絕對(duì)路徑
PackageInfo pInfo = packageManager.getPackageArchiveInfo(apkPath, PackageManager.GET_ACTIVITIES);
if (pInfo != null) {
    //包名
    String packageName = pInfo.packageName;
    //版本名
    String versionCode = pInfo.versionName;
    //版本號(hào)
    String versionCode = pInfo.versionCode;
    ApplicationInfo appInfo = pInfo.applicationInfo;
    /** 必須加這兩句，不然下面icon獲取是default icon而不是應(yīng)用包的icon */
    appInfo.sourceDir = apkPath;
    appInfo.publicSourceDir = apkPath;
    //應(yīng)用名
    String appName = appInfo.loadLabel(packageManager).toString();
    //應(yīng)用圖標(biāo)
    Drawable appIcon = packageManager.getApplicationIcon(appInfo);
    //...其他信息同上獲取已安裝應(yīng)用信息一樣
}

3、根據(jù)包名打開應(yīng)用LauncherActivity

public static void openApplication(Context context, String packageName) throws Exception {
    Intent launcherIntent = new Intent("android.intent.action.MAIN", null);
    launcherIntent.addCategory("android.intent.category.LAUNCHER");
    launcherIntent.setPackage(packageName);
    ResolveInfo localResolveInfo = (ResolveInfo) context.getPackageManager()
                    .queryIntentActivities(launcherIntent, 0).iterator().next();
    if (localResolveInfo != null) {
        String str = localResolveInfo.activityInfo.name;
        Intent targetIntent = new Intent(Intent.ACTION_MAIN);
        targetIntent.addCategory(Intent.CATEGORY_LAUNCHER);
        targetIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        targetIntent.setComponent(new ComponentName(packageName, str));
        context.startActivity(localIntent2);
}

4、獲取所有已安裝應(yīng)用信息

PackageManager packageManager = mContext.getPackageManager();
List<PackageInfo> mPacks = packageManager.getInstalledPackages(0);
for(PackageInfo packageInfo : mPacks) {
    //是否是系統(tǒng)應(yīng)用
    boolean isUserApp = (packageInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0;
    //...同上獲取其他信息
}

5、獲取應(yīng)用大小數(shù)據(jù)

packageManager.getPackageSizeInfo(packageName, new IPackageStatsObserver.Stub() {
    @Override
    public void onGetStatsCompleted(PackageStats packageStats, boolean b) throws RemoteException {
         String package = packageStats.packageName;
         long totalSize = packageStats.cacheSize + packageStats.codeSize + packageStats.dataSize;
});