FileProvider无法使用Camera

Question

我正在尝试使相机应用程序存储输出到我的内部存储。我还知道第三方应用程序不能访问我的应用程序的内部存储，但我们可以通过fileprovider公开内部目录来做到这一点。我在这里遵循了指南：

• 相机意图不保存照片
• https://developer.android.com/reference/android/support/v4/content/fileprovider.html

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.stackoverflow.test.camerawithfileprovider" >

    <application>
        <activity
            ...
        </activity>

        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.stackoverflow.test.camerawithfileprovider.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true" >
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_provider_path" />
        </provider>
    </application>

</manifest>

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

private static final int CAMERA_REQUEST_CODE = 5000;
private static final String CAMERA_FP_AUTHORITY = "com.stackoverflow.test.camerawithfileprovider.fileprovider";

Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

Context context = MainActivity.this;
File imagePath = new File(context.getFilesDir(), "public");
if (!imagePath.exists()) imagePath.mkdirs();
File newFile = new File(imagePath, "tmp.jpg");

Uri imageUri = FileProvider.getUriForFile(context, CAMERA_FP_AUTHORITY, newFile);
//context.grantUriPermission("com.google.android.GoogleCamera", imageUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
Log.d("YouQi", "Image URI Passing to Camera: " + imageUri.toString());

intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, CAMERA_REQUEST_CODE);

当我运行应用程序时，我可以得到以下Logcat结果：

    11-11 20:07:39.581 18303-18303/com.stackoverflow.test.camerawithfileprovider D/YouQi: Image URI Passing to Camera: content://com.stackoverflow.test.camerawithfileprovider.fileprovider/image_capture/tmp.jpg

就在相机关闭的那一刻，我打出了下面的例外：

com.google.android.GoogleCamera E/AndroidRuntime: FATAL EXCEPTION: main
com.google.android.GoogleCamera E/AndroidRuntime: Process: com.google.android.GoogleCamera, PID: 19420
com.google.android.GoogleCamera E/AndroidRuntime: java.lang.SecurityException: Permission Denial: opening provider android.support.v4.content.FileProvider from ProcessRecord{42e44f70 19420:com.google.android.GoogleCamera/u0a83} (pid=19420, uid=10083) that is not exported from uid 10312
com.google.android.GoogleCamera E/AndroidRuntime:     at android.os.Parcel.readException(Parcel.java:1465)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.os.Parcel.readException(Parcel.java:1419)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.app.ActivityManagerProxy.getContentProvider(ActivityManagerNative.java:2882)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.app.ActivityThread.acquireProvider(ActivityThread.java:4544)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.app.ContextImpl$ApplicationContentResolver.acquireUnstableProvider(ContextImpl.java:2274)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1425)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:906)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.content.ContentResolver.openOutputStream(ContentResolver.java:669)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.content.ContentResolver.openOutputStream(ContentResolver.java:645)
com.google.android.GoogleCamera E/AndroidRuntime:     at com.android.camera.PhotoModule.onCaptureDone(PhotoModule.java:1281)
com.google.android.GoogleCamera E/AndroidRuntime:     at com.android.camera.PhotoModule$8.onClick(PhotoModule.java:593)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.view.View.performClick(View.java:4445)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:18446)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:733)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:136)
com.google.android.GoogleCamera E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5146)
com.google.android.GoogleCamera E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
com.google.android.GoogleCamera E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:515)
com.google.android.GoogleCamera E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
com.google.android.GoogleCamera E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
com.google.android.GoogleCamera E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)

谁能解释一下问题发生的原因吗？我创建了一个解决问题的示例项目：http://www.axzae.com/downloads/camerawithfileprovider.zip

context.grantUriPermission(
    "com.google.android.GoogleCamera",
    imageUri,
    Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION
);

Answer 1

>

请不要尝试将exported=“true”如pskink所指出的，您的应用程序将在加载时崩溃。FileProvider不能在此状态下工作。

通过commonsware尝试了intent.addflags解决方案。不管用。可能只适用于action_send类型的意图。

我在这篇帖子里找到了答案。显然，手动授予的方式是唯一的解决办法。但我们总是可以循环遍历候选包列表并将权限授予所有这些包。

List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
for (ResolveInfo resolveInfo : resInfoList) {
    String packageName = resolveInfo.activityInfo.packageName;
    context.grantUriPermission(packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
}