安卓packageinfo的知识点

PackageInfo类包含AndroidManifest.xml文件的信息。

一些常用的属性如下： 

 获得PackageInfo

 //获取指定包名的packageInfo，并且包含所有的内容提供者 
  val pack = context.packageManager.getPackageInfo(
                context.packageName,
                PackageManager.GET_PROVIDERS
            )

//获得手机中安装了的应用的packageInfo，并且包含所有的内容提供者（PackageManager.GET_PROVIDERS）

List packs = context.getPackageManager().getInstalledPackages(PackageManager.GET_PROVIDERS);

想获得什么信息，就填什么flag ,如果想要获得所有的activity

   val pack = context.packageManager.getPackageInfo(
                context.packageName,
                PackageManager.GET_ACTIVITIES
            )

示例：

1.不添加任何flag

 fun getRealPath(context: Context): String? {
        try {
            val pack = context.packageManager.getPackageInfo(
                context.packageName,
                0
            )

获得的PackageInfo的一些信息 

pack = {PackageInfo@9975} "PackageInfo{1956f2d com.example.mytest2}"
 activities = null   //获取的activity为空
 applicationInfo = {ApplicationInfo@9992} "ApplicationInfo{e4e3c62 com.example.mytest2}"
 baseRevisionCode = 0
 compileSdkVersion = 32
 compileSdkVersionCodename = "12"
 configPreferences = null
 coreApp = false
 featureGroups = null
 firstInstallTime = 1686015434025
 gids = null
 installLocation = -1
 instrumentation = null
 isApex = false
 isStub = false
 lastUpdateTime = 1686214196863
 mOverlayIsStatic = false
 overlayCategory = null
 overlayPriority = 0
 overlayTarget = null
 packageName = "com.example.mytest2"
 permissions = null
 providers = null
 receivers = null
 reqFeatures = null
 requestedPermissions = null
 requestedPermissionsFlags = null
 requiredAccountType = null
 requiredForAllUsers = false
 restrictedAccountType = null
 services = null
 sharedUserId = null
 sharedUserLabel = 0
 signatures = null
 signingInfo = null
 splitNames = null
 splitRevisionCodes = null
 targetOverlayableName = null
 versionCode = 0
 versionCodeMajor = 0
 versionName = "1.0"
 shadow$_klass_ = {Class@1937} "class android.content.pm.PackageInfo"
 shadow$_monitor_ = -2120913107

2.添加flags,添加了获得activity的flags

     val pack = context.packageManager.getPackageInfo(
                context.packageName,
                PackageManager.GET_ACTIVITIES
            )

上面不添加flags的获取不到activity，这个可以获取的到

pack = {PackageInfo@9982} "PackageInfo{cd01809 com.example.mytest2}"
 activities = {ActivityInfo[6]@9999} //获取到了activity
 applicationInfo = {ApplicationInfo@10000} "ApplicationInfo{be32a0e com.example.mytest2}"
 baseRevisionCode = 0
 compileSdkVersion = 32
 compileSdkVersionCodename = "12"
 configPreferences = null
 coreApp = false
 featureGroups = null
 firstInstallTime = 1686015434025
 gids = null
 installLocation = -1
 instrumentation = null
 isApex = false
 isStub = false
 lastUpdateTime = 1686214391973
 mOverlayIsStatic = false
 overlayCategory = null
 overlayPriority = 0
 overlayTarget = null
 packageName = "com.example.mytest2"
 permissions = null
 providers = null
 receivers = null
 reqFeatures = null
 requestedPermissions = null
 requestedPermissionsFlags = null
 requiredAccountType = null
 requiredForAllUsers = false
 restrictedAccountType = null
 services = null
 sharedUserId = null
 sharedUserLabel = 0
 signatures = null
 signingInfo = null
 splitNames = null
 splitRevisionCodes = null
 targetOverlayableName = null
 versionCode = 0
 versionCodeMajor = 0
 versionName = "1.0"
 shadow$_klass_ = {Class@1937} "class android.content.pm.PackageInfo"
 shadow$_monitor_ = -1932519415

获取APP信息方式：

ApplicationInfo applicationInfo = packageInfo.applicationInfo;
// APP 包名
String packageName = packageInfo.packageName;
// APP icon
Drawable icon = packageManager.getApplicationIcon(applicationInfo);
// APP 名称
String appName = packageManager.getApplicationLabel(applicationInfo).toString();
// APP 权限
String[] permissions = packageManager.getPackageInfo(packageName,PackageManager.GET_PERMISSIONS).requestedPermissions;

ApplicationInfo类
ApplicationInfo是android.content.pm包下的一个实体类，用于封装应用的信息，flags是其中的一个成员变量public int flags = 0;用于保存应用的标志信息。

ApplicationInfo 可以得到一个应用基本信息。这些信息是从AndroidManifest.xml的< application >标签获取的

ApplicationInfo对象里保存的信息都是标签里的属性值

ApplicationInfo与ResolveInfo比较：前者能够得到Icon、Label、meta-data、description。后者只能得到Icon、Label