Develop Reference

Unable to open trivial text file with FileProvider

I'm going crazy, I used the new Android FileProvider in the past but I can't get it to work with a (trivial) just-created file in the Download folder.
In my AsyncTask.onPostExecute I call
Intent myIntent = new Intent(Intent.ACTION_VIEW, FileProvider.getUriForFile(mContext, BuildConfig.APPLICATION_ID + ".fileprovider", output));
myIntent.setType("text/plain");
myIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(myIntent);
My FileProvider XML is like this
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="Download" path="Download"/>
</paths>
In Genymotion emulator I always get, choosing Amaze Text Editor as target app:
While I can see the file content with HTML Viewer:
I can't understand this behavior and fix what should be a trivial thing like opening a pure-text file with the desidered text editor.
thanks a lot
nicola

OK, there are two problems here. One is a bug in your code that triggers a bug in Amaze, and one is a bug in Amaze that you can work around.
setType() has a nasty side effect: it wipes out your Uri in the Intent. It is the equivalent of calling setDataAndType(null, ...) (where ... is your MIME type). That's not good. So, instead of putting the Uri in the constructor and calling setType(), call setDataAndType() and provide the Uri there.
This gets you past the initial Amaze bug, where they fail to handle a null Uri correctly.
Then, though, they try to open the Uri in read-write mode. You are only granting read access, so this fails. Their second bug is that they think that they get a FileNotFoundException when they cannot open the file in read-write mode, and at that point they try read-only mode. In reality, at least on Android 8.1, they get a SecurityException. You can work around this by providing both read and write permissions.
So, unless you specifically want to block write access, this code works:
Intent myIntent = new Intent(Intent.ACTION_VIEW);
myIntent.setDataAndType(FileProvider.getUriForFile(mContext, BuildConfig.APPLICATION_ID + ".fileprovider", output), "text/plain");
myIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION|Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
startActivity(myIntent);

How to simply open directory/folder?

DONT mark this as duplicate, before reading what I need.
I have seen many similar topics, but in none of them I've found solution.
I need the simplest thing: In my application I have button "View Media Files". After clicking that button, i need to be opened (with built-in File Explorer) this directory - SD_CARD/my_folder where are media files (and I want to click any of them and they should be opened in default Media player)..
I have used all suggested answers on SO , like this:
Intent intent = new Intent(Intent.ACTION_VIEW);
Uri mydir = Uri.parse("/sdcard/Recorder_Videos");
intent.setDataAndType(mydir, "*/*");
startActivity(intent);
but all they do: after clicking button, it opens "Choose File" menu:
(Where I cant still play media files when clicking)

The solution (not complete) I have found, was that I was missing file:// prefix. Here is my solution (however, it shows all kinds of applications on first view):
public void openFolder(String location)
{
// location = "/sdcard/my_folder";
Intent intent = new Intent(Intent.ACTION_VIEW);
Uri mydir = Uri.parse("file://"+location);
intent.setDataAndType(mydir,"application/*"); // or use */*
startActivity(intent);
}
p.s. Strange and surprising, but there doesnt exist the standard definition of "File Browser" in stock Android systems (unless you install 3rd party "File Explorer")..
That's why "resource/folder" mime-type doesnt work by default..
However, let's say a simple truth. File-Browser is a SIMPLE and ESSENTIAL part of any OS system. And it's quite disrespectful from Android, saying that it's not their job, and throwing the responsiblity to 3rd party apps.

You can use type DocumentsContract.Document.MIME_TYPE_DIR which works on several devices and launches File Explorer. You can refer this SO for more details.

Android Attaching a file to GMAIL - Can't attach empty file

I had a program that would always attach the same file to GMAIL (Compose > Attach File > Open From > "MyProgram"). It would always select the same file.
What it was doing was:
String path = Environment.getExternalStorageDirectory() + "/file.3gp";
File f = new File(path);
Uri data = Uri.fromFile(f);
Intent i = new Intent();
i.setData(data);
setResult(Activity.RESULT_OK, i);
finish();
This was working fine until Android 6.0.
Now, I receive the following error when trying to use it:
Can't attach empty file
Astro File Sharing is giving me the same error (can be an old build).
However, I installed ES File Explorer, and when I do the same routine, and select the file, I receive a Dialog which says:
Pick up file as
Normal Android Way (For MMS,Gmail,...)
File Way (Try this if above fails)
The "File Way" will fail as my program does. The "Normal Android Way" will work fine.
Does anyone have any idea on what it does, so I can replicate?
Thanks in advance!
OBS: Already tried the putExtra(STREAM, path) a lot of times, but without success.

Ok, got it to work now, after a lot of research and intercepting some Intents.
What I had to do was change the file:/// to content://.
I did this following this information from Android: https://developer.android.com/reference/android/support/v4/content/FileProvider.html
The only major change was that I used a hard-coded path to /sdcard/file.ext.
Also, the line
getUriForFile(getContext(), "com.mydomain.fileprovider", newFile);
was changed to
Uri contentUri = FileProvider.getUriForFile(this, "com.mydomain.fileprovider", newFile);
Also had to include:
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
i.setData(contentUri);
I do not really understand why I had to change from File to Content, but after this, the file is now being attached again! See the link if you face this issue, and don't forget about the new .xml that needs to be created.

See the following question:
android-6-cannot-share-files-anymore
This behavior is with Android 6.0 and Gmail. Please see the following thread.
Issue 3141 - android-developer-preview
If you go to Settings->Apps->Gmail->Permissions and enable the
"Storage" permission manually, then the share works.
Gmail should ask for "Storage" permission in this scenario and it
would work as it did in all the past version of Android.
Other email apps should handle attachments correctly.

Here is how to fix it.
Go to Settings -> Apps -> Gmail -> Permissions
Turn on the permission for "Storage"
That work-around solved the issue for me.

I couldn't find a clear answer(sending an attachment on gmail without SD card) I tried to copy to another file name but no cigar. The way I got it to work was copy to the Downloads folder and go from there.
Get the path for Downloads with this
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
pulls the full path to downlaods folder copy the attachemnt to there and we are good. Files over 20M don't go

Share any file using INTENT provided given file path
//File file= shareable File Path
Uri uri = FileProvider.getUriForFile(this, "com.example.myapp.fileprovider", file);
//FileProvider authorities from Manifest
Intent sharingIntent = new Intent(Intent.ACTION_SEND);
sharingIntent.setType("*/*");
sharingIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
sharingIntent.putExtra(Intent.EXTRA_STREAM, uri);
startActivity(sharingIntent);
Just match your authorities from the manifest in arguments of method getUriForFile.
In Manifest
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="com.example.myapp.fileprovider"
android:grantUriPermissions="true"
android:exported="false">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/filepaths" />
</provider>

Open a url to a file in Android without using a browser

I am experimenting with Android development. I am making an app that will allow the user to browse files in a web service and view them. These files could be anything: text, pdf, pictures, etc.
Previously, I would download the file to external storage and then call Intent.SetDataAndType() and pass it the URL to the file. That would cause the Android device to bring up an app picker and let the user choose the appropriate method to look at the file.
But since I do not want the user to edit the file, only to look at it, it seemed silly to download a file to storage; a file that I didn't want to hang around. Since the file can be obtained by a URL, why don't I pass that as a parameter to the Intent.SetDataAndType()?
I tried that. The first problem was that the file name was assumed to be the name of the web service call, and that seemed to be more important than the mime-type. I changed the web service to be the same name as whatever file was attempting to be downloaded. That solved that issue.
So now, the file is being opened. But it is always being opened in a web browser. I get to choose the web browser, but I would rather have another app open it.
My code looks like this:
Intent i = new Intent(Intent.ActionView);
i.SetDataAndType(Android.Net.Uri.Parse(GetUrlToFile(fileref, fileName)), mimeType);
i.SetFlags(ActivityFlags.GrantReadUriPermission);
i.SetFlags(ActivityFlags.NewTask);
i.SetFlags(ActivityFlags.ClearWhenTaskReset); // so if the app is relaunched, we don't show the display application.
StartActivity(i);
The code is in C# because I'm using Xamarin, but I don't believe that should make a difference.
I tried using StartActivity(Intent.CreateChooser(i, "Open me")); but that didn't give me any more options for choosing.
Does anyone have any ideas as to how to do this?

I have not found a way to do this yet, so I have gone through a workaround.
Instead of using a URL, I changed my app to be a Content Provider as well. Now, when I want the file opened, I create a URI that refers to the file within my app and pass that off to an Intent. When my app is contacted by this Intent, I download the file locally to my cache directory and return that.
My code has changed to this:
Intent i = new Intent(Intent.ActionView);
i.SetDataAndType(Android.Net.Uri.Parse("content://com.sample.erik.provider/files/" + id), mimeType);
i.SetFlags(ActivityFlags.GrantReadUriPermission);
i.SetFlags(ActivityFlags.NewTask);
i.SetFlags(ActivityFlags.ClearWhenTaskReset); // so if the app is relaunched, we don't show the display application.
StartActivity(i);
Then, I have my own content provider which does most of the work in OpenFile()
public override ParcelFileDescriptor OpenFile(Android.Net.Uri uri, string mode)
{
switch (sUriMatcher.Match(uri))
{
case FILE_ID:
if (mode != "r")
throw new Java.Lang.UnsupportedOperationException("Do not support write access: " + uri);
String id = uri.LastPathSegment;
Java.IO.File file = new Java.IO.File(Application.Context.CacheDir, id);
DownloadToFile(file, id);
return ParcelFileDescriptor.Open(file, ParcelFileMode.ReadOnly);
default:
throw new Java.Lang.IllegalArgumentException("Unknown Uri: " + uri);
}
}
It is not my original plan, but this way seems to work quite well and meets my needs.

Android: How do I attach a temporary, generated image to an email?

I have a programmatically generated image that I want to send as an attachment via the ACTION_SEND and EXTRA_STREAM method.
But how do i do this?
My first attempt (writing to my context.getCacheDir() based file path) appeared to work in the Gmail preview (no image preview, but attached file name and icon was visible), but the attachment never arrived on the recipient side. I guess this has something to do with permissions on the generated file, but how to avoid this? Do I need to set more permissive settings on these generated files (so that the Gmail activity can access)? Is that even possible for the app's cache folder?
Is there another file location that would be more suitable to write my files to? I considered the downloads folder, but think it would be an awkward location for something that only needs to exist until it has been emailed.
I have even tried encoding my image purely in a data:image/png;base64,ABCD... style URI. This, too, showed up in Gmail preview (attachment icon, but no file name), but did not result in a recipient-side attachment.
Has anyone been able to attach a one-shot generated image to an email intent by any means? What options may I have overlooked?

My problem really consisted of two parts:
context.getCacheDir() is private to your app. You can't put something there and expect another app to be able to access it.
I misunderstood what MIME type I should have been using. Even though I was sending email text, I really needed to specify image/png for the sake of my attachment.
Additionally, research indicated that putting (potentially large) images on the primary memory was not a good idea, even if you were going to immediately clean it up.
Once I did these things and wrote my generated images to a public location on the SD Card, it worked just fine.
So, in overview:
Request SD Card Access in your manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Make sure SD Card is available
if (!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
{
//Bail gracefully
}
Create a directory on the SD Card
File pngDir = new File(
Environment.getExternalStorageDirectory(),
//Loose convention inferred from app examples
"Android/data/com.somedomain.someapp/flotsam");
if (!pngDir.exists())
pngDir.mkdirs();
Write your file to that directory and capture the Uri
File pngFile = new File(pngDir, "jetsam.png");
//Save file encoded as PNG
Uri pngUri = Uri.fromFile(pngFile);
Build an ACTION_SEND intent
Intent intent = new Intent(android.content.Intent.ACTION_SEND);
intent.setType("image/png"); //
intent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[] { "someone#somewhere.com" });
intent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Portable Network Graphics");
intent.putExtra(android.content.Intent.EXTRA_CC, new String[] { "carbon#somewhere.com" });
intent.putExtra(Intent.EXTRA_TEXT, "Something textual");
intent.putExtra(Intent.EXTRA_STREAM, pngUri);
And then start the activity
context.startActivity(Intent.createChooser(intent, "Something Pithy"));
And then make sure you clean everything up...
Caveat 1
There appears to be more support coming for app-specific SD Card directories, but alas, not in my required SDK version.
Caveat 2
This is an overview of the solution that eventually worked for me. It is not necessarily a "best practice" approach.
Caveat 3
This does mean that the application has to have an SD Card mounted in order to have the image attachments feature available, but this was totally acceptable for my use case. Your mileage may vary. If the SD Card is not available, I append a friendly note to the email explaining why the images could not be attached and how to rectify the situation.

I've just run into exactly the same issue (wanting to attach a text file in my case). If you look in the Android log, the reason for it is:
02-28 21:01:28.434: E/Gmail(19673): file:// attachment paths must point to file:///mnt/sdcard. Ignoring attachment file:///data/data/com.stephendnicholas.gmailattach/cache/Test.txt
As a workaround (as mentioned by HRJ), you can use a ContentProvider to provide access to files in your application's internal cache so that Gmail can attach them. I've just written up a blog post on how to do it.
Hopefully that's of some help :)

tableLayout.buildDrawingCache();
Bitmap test = Bitmap.createBitmap(tableLayout.getDrawingCache());
tableLayout.destroyDrawingCache();
Log.d("Image", test.toString());
String path = Environment.getExternalStorageDirectory().toString();
Log.d("Path", path);
File file = new File(path,"mail_image.png");
Uri pngUri = Uri.fromFile(file);
Log.d("Real Image Path", pngUri.toString());
Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
emailIntent.setType("image/png");
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, "email to");
emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT,"Subject");
emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, "From My App");
emailIntent.putExtra(android.content.Intent.EXTRA_STREAM, pngUri );
startActivity(Intent.createChooser(emailIntent, "Send mail..."));