我发现，如果我用compileSdkVersion构建我的应用程序，buildToolsVersion和targetSdkVersion都设置为默认值30在我的构建。Gradle文件，那么应用程序将无法安装在我的手机上。但是，如果我把它们改回版本29，它就可以工作了。问题是，从SDK 30开始，你需要选择V2 jar签名。有关更多信息，请参阅为什么Android SDK 30生成无效的APK文件?

我的问题和@Lunatikzx的问题类似。由于错误的权限标记被写入应用程序的属性:

<application
    android:permission="android.permission.WRITE_EXTERNAL_STORAGE"
    android:label="@string/app_name"
    android:icon="@drawable/ic_launcher"
    android:testOnly="false"
    android:debuggable="true">

什么为我修复它是改变权限标签，像这样单独的标签:

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

当我将android从2.3.2升级到3.0.1时，我就遇到了这个问题。如果是这种情况，IDE将自动考虑以下几点。

1.你不能通过传统的方法安装android:testOnly="true"的应用程序，例如从android文件管理器或从网站下载

2.Android Studio在运行的apk上设置Android:testOnly="true

如果您运行应用程序时直接将设备连接到系统，apk将安装和运行没有问题。

如果你从构建、放置和调试文件夹中复制这个apk，它将永远不会安装到设备中。

解决方案:Build -> Build APK(s) ->复制APK文件共享到您的团队

这样你的问题就解决了。

我知道这是一个老帖子，但对新用户可能有用。我也遇到了同样的问题:我的应用程序在调试时工作得很好。当我签署APK时，我得到了同样的消息:“应用程序未安装”。

我修复了卸载JDK(我使用的是JDK -6u14-windows-x64)并安装了一个新的JDK (JDK -6u29-windows-x64)。导出并再次签署APK后，一切正常!

恢复，我的问题是在JAVA版本。谢谢的甲骨文! !

这也可能发生在制作主屏幕小部件时，并且您的小部件XML文件在其android:configure属性中指定了错误的Activity。

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.