这个答案只与使用本机库(Android NDK)的应用程序相关。

在我的案例中，问题在于jniLibs中缺少一些用于目标电话CPU架构的本机库。因此，应用程序可以在模拟器上运行，但在真正的手机上，我看到“应用程序未安装”。

我最初只复制了x86架构的编译本机库，所以应用程序可以在模拟器上运行。但是，其他体系结构缺失(x86_64、armeabi_v7a、arm64-v8a)。在添加了缺失的*之后。所以所有架构的文件到jniLibs，“App未安装”错误消失了。

我也遇到了同样的问题，即App显示为正在安装，但当点击图标时不会启动。经过一些头部撞击，我发现我已经愚蠢地放置了' android:exported="false" '为我的主启动器活动在AndroidManifest文件....一旦我删除它，应用程序启动正常。

Clearly there are many causes of this problem. For me the situation was this: I had deployed to my nexus 7 (actual device) from within the Android Studio (v1.3.2). All worked fine. I then created a signed apk and uploaded to my Google Drive. After disconnecting my nexus from the usb, I went to the settings/apps and uninstalled my app (App1). I then opened google drive and clicked on my App1.apk and chose to install it (need to ensure you have allowed installation of apks in settings). Then I got the dreaded message "App not Installed"

Solution for me: go back into settings/apps and scroll though all apps and at the bottom was a pale version of my App1 (note the original App1 was at the top in Alphabetical order which was deleted as above). When clicking on the pale version it said "Not installed for this user". (I had set up my nexus to have more than one user). But in the top right corner there is a three dot button. I pressed this and it said "Uninstall for all users". Which I did and it fixed the problem. I was now able to click on App1.apk and it installed fine without the error.

如果应用程序已经安装到或移动到SD卡上，然后连接了USB线，导致SD卡卸载，也会出现“应用程序未安装”错误。

在这种情况下，关闭USB存储或将应用程序移回内部存储可以解决这个问题。

如果你在AndroidManifest.xml中声明了两次MainActivity，就会发生这种情况。

另一个可能的原因是:您更改了启动活动。提示:永远不要对已经发布的应用程序这样做!原因在Android开发者博客中讨论过。

您也可能会遇到此问题，因为您的设备制造商没有授权谷歌商业应用程序，如Play Store, YouTube，谷歌地图等。按照这个答案来解决问题。