安装 apk 时提供商崩溃

Question

我想在 Android 7 上以编程方式安装一个 apk。当我搜索时，我必须为此使用提供程序，但该应用程序一直崩溃。如果有人能告诉我原因，我将不胜感激。

Android 清单：（在应用程序标签内）

        <provider
            android:name=".GenericFileProvider"
            android:authorities="com.hamed.demo"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"/>
        </provider>

安装代码：

Intent install = new Intent(Intent.ACTION_VIEW);
install.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
install.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
// the following line crashes
Uri apkUri = FileProvider.getUriForFile(AppsList.this,
BuildConfig.APPLICATION_ID + ".provider", file);
install.setDataAndType(apkUri, downloadManager[0].getMimeTypeForDownloadedFile(downloadId));
startActivity(install);

provider_path.xml 在 res/xml:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="external_files" path="."/>
</paths>

我的 GenericFileProvider class 完全是

但是当它到达我添加评论的那一行时，应用程序崩溃了，我遇到了这个错误：

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.hamed.demo, PID: 13090
                  java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.DOWNLOAD_COMPLETE flg=0x10000011 pkg=com.hamed.demo (has extras) } in com.hamed.demo.AppsList@ce55de9
                      at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1153)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:241)
                      at android.app.ActivityThread.main(ActivityThread.java:6274)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
                   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.PackageItemInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
                      at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:584)
                      at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:558)
                      at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:400)
                      at com.hamed.demo.AppsList.onReceive(AppsList.java:217)
                      at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1143)
                      at android.os.Handler.handleCallback(Handler.java:751) 
                      at android.os.Handler.dispatchMessage(Handler.java:95) 
                      at android.os.Looper.loop(Looper.java:241) 
                      at android.app.ActivityThread.main(ActivityThread.java:6274) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

如果重要，下载的 apk 位于设备内部存储的 downloads 目录中。

谢谢

Answer 1

尝试使用此代码

File file = new File(
                Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),
                "app.apk");

        final Uri uri = Uri.fromFile(file);
        final String AUTHORITY = "com.company.app.update.provider";

        if (file.exists())
            file.delete();

        DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        DownloadManager.Request request = new DownloadManager.Request(
                Uri.parse("https://example.com/app.apk"));
        request.setDestinationUri(uri);
        downloadManager.enqueue(request);

        final BroadcastReceiver onComplete = new BroadcastReceiver() {

            public void onReceive(Context context, Intent intent) {

                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {

                    Uri contentUri = FileProvider.getUriForFile(context, AUTHORITY, file);
                    Intent openFileIntent = new Intent(Intent.ACTION_VIEW)
                            .setDataAndType(contentUri, "application/vnd.android.package-archive")
                            .addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(openFileIntent);
                    unregisterReceiver(this);
                    finish();

                } else {

                    Intent openFileIntent = new Intent(Intent.ACTION_VIEW)
                            .setDataAndType(uri, "application/vnd.android.package-archive")
                            .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(openFileIntent);
                    unregisterReceiver(this);
                    finish();
                }
            }
        };

        registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));

安装 apk 时提供商崩溃

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