I am trying to read the text from a QRcode image on my mobile app. I am using Xamarin.Forms with ZXing NuGet package.
I have been able to get the file using Xamarin.Essentials FilePicker. But I don't know how to actually read the barcode. I have looked at some stackoverflow solutions and they all seem to be Xamarin.Android based (using BinaryBitmap objects). I need a solution that can work for iOS and UWP as well. Here is what I have so far:
string file = "";
var filePickerOptions = new PickOptions
{
PickerTitle = "Select Barcode Image",
FileTypes = FilePickerFileType.Images
};
var result = await FilePicker.PickAsync(filePickerOptions);
if (result != null)
{
file = result.FullPath;
var res = Decode(file, BarcodeFormat.QR_CODE);
Console.WriteLine(res.Text);
}
public Result Decode(string file, BarcodeFormat? format = null, KeyValuePair<DecodeHintType, object>[] aditionalHints = null)
{
var r = GetReader(format, aditionalHints);
/* I need some function here that will allow me to get the BinaryBitmap from the image file path or something along those lines.*/
var image = GetBinaryBitmap(file);
var result = r.decode(image);
return result;
}
MultiFormatReader GetReader(BarcodeFormat? format, KeyValuePair<DecodeHintType, object>[] aditionalHints)
{
var reader = new MultiFormatReader();
var hints = new Dictionary<DecodeHintType, object>();
if (format.HasValue)
{
hints.Add(DecodeHintType.POSSIBLE_FORMATS, new List<BarcodeFormat>() { format.Value });
}
if (aditionalHints != null)
{
foreach (var ah in aditionalHints)
{
hints.Add(ah.Key, ah.Value);
}
}
reader.Hints = hints;
return reader;
}
https://github.com/Redth/ZXing.Net.Mobile/issues/981. This thread solved it for me. Credit to #jason for this response.
Related
I'm trying to resize imagine with System.Drawing but im taking that file as IFormFile and when i use the System.Drawing its just keep warning me to about that : cannot implicitly convert type 'System.Drawing.Bitmap' to 'Microsoft.AspNetCore.Http.IFormFile' . I need to resize those photos and save them as IFormFile but i dont know how to do that.
public Task<IFormFile> ResizeImagine300x300(IFormFile file)
{
Image image = Image.FromStream(file.OpenReadStream(), true, true);
var newImage = new Bitmap(1024, 768);
using (var g = Graphics.FromImage(newImage))
{
g.DrawImage(image, 0, 0, 1024, 768);
};
return newImage;//the point where i get the error
}
Is it possible to do it in my way?
If its not possible, then which way i should follow?
Thanks for any suggestion
Edit: I wanna return as a IFormFile because i have a method which is uploading those files to my database. here is my method :
public async Task<FileRepo> FileUploadToDatabase(List<IFormFile> files)
{
foreach (var file in files)
{
var fileName = Path.GetFileNameWithoutExtension(file.FileName);
var fileExtension = Path.GetExtension(file.FileName);
_fileRepo = new FileRepo
{
FileName = fileName,
FileExtension = fileExtension,
FileType = file.ContentType,
CreatedDate= DateTime.Now
};
using (var dataStream = new MemoryStream())
{
await file.CopyToAsync(dataStream);
_fileRepo.FileData = dataStream.ToArray();
}
}
return _fileRepo;
}
After that I'm uploading that _fileRepo variable to my database like that :
var File = _fileUploader.FileUploadToDatabase(files);
var FileResult = File.Result;
FileResult.ProductID = ProductID;
_unitOfWorkFR.RepositoryFileRepo.Create(FileResult);
I'm trying to update my app to work with androids new scoped storage rules in Android 10 and up, but am having the hardest time with it. I know I need to rebuild my app with new versions of java, but I just want to get it to work while I study and learn enough to do so. In a nutshell, I really need help. I have read so many different ways to make scoped storage work, and everybody seems to be doing it differently.
Just for clarification, what I am trying to do with the uri is both display in an imageview, then upload to database.
This code is working to take a picture and select images and videos in android 9, but in android 10, it only works when camera component captures a picture or a video. When a user selects an image or video from file, it returns a null pointer exception. Because I am pretty sure the error is in how I am dealing with the different chooser intents, I have shown the on result code first.
I have been unable to find a clear example of how to retrieve a usable image or video uri in android 10. If anybody can help, I would really appreciate it. I know I have much to learn.
if ((new java.io.File(_filePath)).exists()){
} else {
_filePath = vidfile.getAbsolutePath();
if ((new java.io.File(_filePath)).exists()){
} else {
ArrayList<String> _filePath_1 = new ArrayList<>();
if (_data != null) {
if (_data.getClipData() != null) {
for (int _index = 0; _index < _data.getClipData().getItemCount(); _index++) {
ClipData.Item _item = _data.getClipData().getItemAt(_index);
_filePath_1.add(FileUtil.convertUriToFilePath(getApplicationContext(),
_item.getUri()));
}
}
else {
_filePath_1.add(FileUtil.convertUriToFilePath(getApplicationContext(),
_data.getData()));
}
}
_filePath = _filePath_1.get((int)0);
}
}
Just in case I am wrong, here is the code for the click event to launch the chooser...
SimpleDateFormat date1 = new SimpleDateFormat("yyyyMMdd_HHmmss");
String fileName1 = date1.format(new Date()) + ".jpg";
picfile = new
File(getApplicationContext().getExternalFilesDir(Environment.DIRECTORY_DCIM).getAbsolutePath() +
File.separator + fileName1);
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
Uri _uri_camr1 = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
_uri_camr1 = FileProvider.getUriForFile(getApplicationContext(),
getApplicationContext().getPackageName() + ".provider", picfile);
}
else {
_uri_camr1 = Uri.fromFile(picfile);
}
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, _uri_camr1);
takePictureIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
SimpleDateFormat date2 = new SimpleDateFormat("yyyyMMdd_HHmmss");
String fileName2 = date2.format(new Date()) + ".mp4";
vidfile = new
File(getApplicationContext().getExternalFilesDir(Environment.DIRECTORY_DCIM).getAbsolutePath() +
File.separator + fileName2);
Intent takeVideoIntent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
Uri _uri_camr2 = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
_uri_camr2 = FileProvider.getUriForFile(getApplicationContext(),
getApplicationContext().getPackageName() + ".provider", vidfile);
}
else {
_uri_camr2 = Uri.fromFile(vidfile);
}
takeVideoIntent.putExtra(MediaStore.EXTRA_OUTPUT, _uri_camr2);
takeVideoIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
contentSelectionIntent.setType("*/*");
contentSelectionIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
Intent[] intentArray = new Intent[]{ takePictureIntent, takeVideoIntent};
chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
chooserIntent.putExtra(Intent.EXTRA_TITLE, "Choose an action");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
startActivityForResult(chooserIntent, REQ_CD_CAMR);
try this code. it copies the selected file to scoped storage and gives you the final path of scoped storage from where you can access it. try it out & let me know if you face any problem.
android.net.Uri sharedFileUri = android.net.Uri.fromFile(new java.io.File(_filepath));
java.io.FileInputStream input = null;
java.io.FileOutputStream output = null;
try {
String filePath = new java.io.File(getCacheDir(), "tmp").getAbsolutePath();
android.os.ParcelFileDescriptor pfd = getContentResolver().openFileDescriptor(sharedFileUri, "rw");
if (pfd != null) {
java.io.FileDescriptor fd = pfd.getFileDescriptor();
input = new java.io.FileInputStream (fd);
output = new java.io.FileOutputStream (filePath);
int read;
byte[] bytes = new byte[4096];
while ((read = input.read(bytes)) != -1) {
output.write(bytes, 0, read);
}
java.io.File sharedFile = new java.io.File(filePath);
String finalPath = sharedFile.getPath(); // this will provide you path to scoped storage. use this final path to access the selected file from scoped storage.
}
}catch(Exception ex) {
android.widget.Toast.makeText(this, ex.toString(), android.widget.Toast.LENGTH_SHORT).show();
} finally {
try {
input.close();
output.close();
} catch (Exception ignored) {
}
}
In my app I need to pass images from one page to another page image view to display. I am taking a photo from camera and do some stuffs, then I want to send that images to the second page.
if (await isCamAvailable())
{
MediaFile photo1 = await CrossMedia.Current.TakePhotoAsync(new StoreCameraMediaOptions() { Directory = "NewBusiness", Name = "image1.jpg", PhotoSize = PhotoSize.MaxWidthHeight, MaxWidthHeight = 1024, CompressionQuality = 95 });
if (photo1 != null)
{
PhotoImage1.Source = ImageSource.FromStream(() => { return photo1.GetStream(); });
countList.Remove("a");
countList.Add("a");
}
}
Then I am added it to a string array by doing
private List<string> sendImgList = new List<string>();
sendImgList.Add(createImgByteString(photo1.GetStream()));
private string createImgByteString(Stream data)
{
var bytes = new byte[data.Length];
return Convert.ToBase64String(bytes);
}
Then from second page (for testing i just added only one image)
foreach (string ss in imgList) {
byte[] Base64Stream = Convert.FromBase64String(ss);
imgView.Source = ImageSource.FromStream(() => new MemoryStream(Base64Stream));
}
I followed this example. But image not showing.
https://forums.xamarin.com/discussion/139360/how-to-transfer-images-from-one-page-to-another
Also getting this in logcat..
[0:] ImageLoaderSourceHandler: Image data was invalid: Xamarin.Forms.StreamImageSource05-29 14:22:43.758 W/monodroid-assembly( 8737): typemap: unable to find mapping to a Java type from managed type 'System.Byte, mscorlib'
It seems that you used the Media.Plugin . Why don't you pass the ImageSource directly?
If you do want to convert it to byte array , check the following code
public byte[] GetImageStreamAsBytes(Stream input)
{
var buffer = new byte[16*1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}
var imgDate = GetImageStreamAsBytes(photo1.GetStream());
It would be better to pass the byte array directly .
The best mode to pass parameter in pages is with Prism.
https://prismlibrary.com/docs/xamarin-forms/navigation/passing-parameters.html
>
_navigationService.NavigateAsync(new Uri("MainPage", new NavigationParameters
{
{ "key_parameter", image }
})));
And on other page:
>
public override void OnNavigatedTo(INavigationParameters parameters)
{
image = (Image)parameters["key_parameter"];
}
I get this error when running this code. I have looked for solution though I don't like the idea of using MARS as people have suggested as it may contain a lot of data, is there any other option here? Also can I edit a variable in a database without rewriting all of them as I do here, will this save server power or make no difference?
There is already an open DataReader associated with this Command which must be closed first.
public ActionResult CheckLinks(Link model)
{
var userId = User.Identity.GetUserId();
var UserTableID = db.UserTables.Where(c => c.ApplicationUserId == userId).First().ID;
foreach (var item in db.Links.Where(p => p.UserTable.ID == UserTableID))
{
string pageContent = null;
HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(item.Obdomain);
HttpWebResponse myres = (HttpWebResponse)myReq.GetResponse();
using (StreamReader sr = new StreamReader(myres.GetResponseStream()))
{
pageContent = sr.ReadToEnd();
}
string live = "";
if (pageContent.Contains(item.Obpage))
{
live = "Yes";
}
else { live = "No"; }
var link = new Link { Obdomain = item.Obdomain, ClientID = item.ClientID, Obpage = item.Obpage, BuildDate = item.BuildDate, Anchor = item.Anchor, IdentifierID = item.IdentifierID, live = (Link.Live)Enum.Parse(typeof(Link.Live), live), UserTableID = item.UserTableID };
db.Entry(link).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index");
}
Entity Framework allows only one active command per context at a time. You should add .ToList() at the end of the following statement:
db.Links.Where(p => p.UserTable.ID == UserTableID).ToList();
So your code could look like this:
var items = db.Links.Where(p => p.UserTable.ID == UserTableID).ToList();
foreach (var item in items)
Is there a way to read an embedded JSON file in a PCL project with PCLStorage module? I looked everywhere but couldn't find a sample related to this matter.
EDIT: PCLStorage link: https://github.com/dsplaisted/pclstorage
you need something like this:
public static async Task<string> ReadFileContent(string fileName, IFolder rootFolder)
{
ExistenceCheckResult exist = await rootFolder.CheckExistsAsync(fileName);
string text = null;
if (exist == ExistenceCheckResult.FileExists)
{
IFile file = await rootFolder.GetFileAsync(fileName);
text = await file.ReadAllTextAsync();
}
return text;
}
to use:
IFolder rootFolder = FileSystem.Current.LocalStorage;
IFolder myCoolFolder = await rootFolder.CreateFolderAsync("MyCoolForler", CreationCollisionOption.OpenIfExists);
string fileContent = await this.ReadFileContent("MyCoolFile.txt", myCoolFolder);
You should be able to read embedded resources like this:
var assembly = typeof(LoadResourceText).GetTypeInfo().Assembly;
Stream stream = assembly.GetManifestResourceStream("WorkingWithFiles.PCLTextResource.txt");
string text = "";
using (var reader = new System.IO.StreamReader (stream)) {
text = reader.ReadToEnd ();
}
Xamarin has a great guide on how to work with them here.
https://developer.xamarin.com/guides/cross-platform/xamarin-forms/working-with/files/