/// <summary>
/// liefert selbst innerhalb des secondary ext. storage bei Oreo eine Exception: "Copy not supported"
/// <para>Das scheint eine Exception der abstrakten Klasse DocumentProvider zu sein, d.h. die Copy-Funktion wurd in der konkreten Klasse nicht implemetiert.
/// Das Flag FLAG_SUPPORTS_COPY für Dokumente fehlt (deswegen).</para>
/// </summary>
/// <param name="storagenamesrc"></param>
/// <param name="volpathsrc"></param>
/// <param name="storagenamenewparent"></param>
/// <param name="volpathnewparent"></param>
/// <returns></returns>
public bool Copy(string storagenamesrc, string volpathsrc, string storagenamenewparent, string volpathnewparent)
{
DocumentFile srcdoc = GetExistingDocumentFile(storagenamesrc, volpathsrc);
DocumentFile dstparentdoc = GetDocumentFile(storagenamenewparent, volpathnewparent, true); // Zielverzeichnis (wird notfalls erzeugt)
/* Added in API level 24; Nougat, 7.0, Deprecated in API level Q
*
* public static Uri copyDocument (ContentResolver content,
* Uri sourceDocumentUri, Document mit FLAG_SUPPORTS_COPY
* Uri targetParentDocumentUri)
*
* neu:
* ContentProviderClient provclient = Activity.ContentResolver.AcquireUnstableContentProviderClient(srcdoc.Uri.Authority);
* DocumentsContract.CopyDocument(provclient, srcdoc.Uri, dstparentdoc.Uri);
*
* intern:
* Bundle inbundle = new Bundle();
* inbundle.PutParcelable(DocumentsContract.EXTRA_URI, srcdoc.Uri); "uri"
* inbundle.PutParcelable(DocumentsContract.EXTRA_TARGET_URI, dstparentdoc.Uri); "android.content.extra.TARGET_URI"
* Bundle outbundle = provclient.Call(METHOD_COPY_DOCUMENT, null, inbundle); "android:copyDocument"
* return outbundle.GetParcelable(DocumentsContract.EXTRA_URI); "uri"
*/
global::Android.Net.Uri newuri = DocumentsContract.CopyDocument(Activity.ContentResolver,
srcdoc.Uri,
dstparentdoc.Uri);
System.Diagnostics.Debug.WriteLine("AndroidCopy(" + storagenamesrc + ", " + volpathsrc + ", " + storagenamenewparent + ", " + volpathnewparent + ") = " + (newuri != null).ToString());
return(newuri != null);
}
