Question

我的应用程序中有一个首选项页面，该页面要求用户提供保存文件的位置。使用Storage Access Framework将该位置作为URI返回，并且我可以使用它在活动之间存储文件。问题是重启电话后，我从sharedPreferences中检索了URI，并且收到了以下消息：

DocumentFile: Failed query: java.lang.SecurityException: Permission Denial: opening provider com.android.externalstorage.ExternalStorageProvider from ProcessRecord (pid=23302, uid=10334) requires that you obtain access using ACTION_OPEN_DOCUMENT or related APIs

以下是启动意图的代码：

 folderPicker = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)        
 folderPicker.addFlags(Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION)
 startActivityForResult(folderPicker, READ_REQUEST_BY_USER)

和onActivityResult：

    val takeFlags: Int = folderPicker.flags and (Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
    activity!!.contentResolver!!.takePersistableUriPermission(uri, takeFlags)
    val sharedPref = PreferenceManager.getDefaultSharedPreferences(activity?.baseContext)
    with (sharedPref.edit()) {
    putString("savePathURI", uri.toString())
    commit()
    }

这是我尝试重新访问该文件夹的方法：

var uri = PreferenceManager.getDefaultSharedPreferences(this).getString("savePathURI","")                
var getSelectedDocument = DocumentFile.fromTreeUri(applicationContext, Uri.parse(uri))!!
var params = BridgeParams(applicationContext, links, filesDir.absolutePath, button, getResources(), progressBar3, getSelectedDocument, contentResolver)

编辑：我注意到，即使我之后立即调用它，调用contentResolver.persistedUriPermissions总是返回一个空数组。

activity!!.contentResolver!!.takePersistableUriPermission(uri, takeFlags)

Answer 1

您需要在takePersistableUriPermission上致电onActivityResult

请参阅：https://developer.android.com/reference/android/content/ContentResolver.html?authuser=1#takePersistableUriPermission(android.net.Uri,%2520int)

Answer 2

问题是我需要为ACTION_OPEN_DOCUMENT_TREE添加其他标志：

folderPicker = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)        
folderPicker.addFlags(
Intent.FLAG_GRANT_READ_URI_PERMISSION
or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
or Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION
or Intent.FLAG_GRANT_PREFIX_URI_PERMISSION
)
startActivityForResult(folderPicker, READ_REQUEST_BY_USER)

在Android应用中重启后尝试打开文件夹时出现权限错误

2 个答案: