打算在android N上安装apk

Question

我试图在Android N上安装APK。我使用以下代码：

File toInstall = new File(appDirectory, appName + ".apk");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    Uri apkUri = FileProvider.getUriForFile(activity, BuildConfig.APPLICATION_ID + ".provider", toInstall);
    Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);
    intent.setData(apkUri);
    intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    activity.startActivity(intent)
} else {
    Uri apkUri = Uri.fromFile(toInstall);
    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(apkUri, "application/vnd.android.package-archive");
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    activity.startActivity(intent);
}

但我遇到以下错误：

    FATAL EXCEPTION: Thread-5
Process: com.myapp.myapp, PID: 16557
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:583)
at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:557)
at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:399)
at ir.myapp.picwriter.service.MyService$1.run(MyService.java:57)
at java.lang.Thread.run(Thread.java:761)

该行中的错误是：

Uri apkUri = FileProvider.getUriForFile(activity, BuildConfig.APPLICATION_ID + ".provider", toInstall);

Answer 1

我对此有很多问题，终于找到了答案。 这是希望对您有用的答案。

    File toInstall = new File(url);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        File newFile = new File(new File(Environment.getExternalStorageDirectory(), "apps"), getImageNameByUrl(appUrl));
        Uri apkUri = getUriForFile(context, BuildConfig.APPLICATION_ID+".provider", newFile);
        Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);
        intent.setData(apkUri);
        intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        context.startActivity(intent);
    } else {
        Uri apkUri = Uri.fromFile(toInstall);
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(apkUri, "application/vnd.android.package-archive");
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    }

manifest ：

    <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>

和file_paths ：

<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="." path="." />
</paths>

和API> 25的权限

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

Answer 2

如果在清单文件中找不到文件提供者，则必须执行以下操作来定义它：

<provider
    android:name="android.support.v4.content.FileProvider"
    android:authorities="com.mydomain.fileprovider"
    android:exported="false"
    android:grantUriPermissions="true">
    ...
</provider>

这里是有关设置FileProvider的文档的链接。 https://developer.android.com/reference/android/support/v4/content/FileProvider.html