Not able to convert an image URL to Bitmap, in Xamarin.android - xamarin

I need to convert a string image https URL to Bitmap, the solution in stack overflow does not work for me.
public static Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}`
If i use this code, it gives me many reference error in C#.

According to your description, I guess that you want to download image from url and convert into bitmap?
If yes, I suggest you can take a look the following code:
private Bitmap GetImageBitmapFromUrl(string url)
{
Bitmap imageBitmap = null;
using (var webClient = new WebClient())
{
var imageBytes = webClient.DownloadData(url);
if (imageBytes != null && imageBytes.Length > 0)
{
imageBitmap = BitmapFactory.DecodeByteArray(imageBytes, 0, imageBytes.Length);
}
}
return imageBitmap;
}
Then you can display this image in ImageView.
private ImageView image;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
image = FindViewById<ImageView>(Resource.Id.imageView1);
var imageBitmap = GetImageBitmapFromUrl("https://cdn1.iconfinder.com/data/icons/general-9/500/add-512.png");
image.SetImageBitmap(imageBitmap);
}
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/imageView1"/>

Related

IMB barcode could not be read

I have tried to read IMB barcode from an image with the below code snippet, but it always return null. I have also tried with the IMB barcode images in the blackbox testing below, but doesn't work.
https://github.com/micjahn/ZXing.Net/tree/master/Source/test/data/blackbox/imb-1
private static void Decode()
{
Bitmap bitmap = new Bitmap(#"\07.png");
try
{
MemoryStream memoryStream = new MemoryStream();
bitmap.Save(memoryStream, ImageFormat.Bmp);
byte[] byteArray = memoryStream.GetBuffer();
ZXing.LuminanceSource source = new RGBLuminanceSource(byteArray, bitmap.Width, bitmap.Height);
var binarizer = new HybridBinarizer(source);
var binBitmap = new BinaryBitmap(binarizer);
IMBReader imbReader = new IMBReader();
Result str = imbReader.decode(binBitmap);
}
catch { }
}
I have solved this problem by using the below code snippet shared through the below link.
https://github.com/micjahn/ZXing.Net/issues/59
private static void Decode2()
{
var bitmap = new Bitmap(#"\07.png"); // make sure that the file exists at the root level
try
{
var imbReader = new BarcodeReader
{
Options =
{
PossibleFormats = new List<BarcodeFormat> {BarcodeFormat.IMB}
}
};
var result = imbReader.Decode(bitmap);
if (result != null)
System.Console.WriteLine(result.Text);
else
System.Console.WriteLine("nothing found");
}
catch (System.Exception exc)
{
System.Console.WriteLine(exc.ToString());
}
}

Xamarin.Forms Xamarin Android

SaveFileDialog in XamarinForms
My requirement is to save a file in Xamarin.Forms like below image and what ever I tried so far is:
public class CustomWebViewRenderer : WebViewRenderer
{
protected override void OnElementChanged (ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged (e);
if (e.NewElement != null)
{
var customWebView = Element as CustomWebView;
Control.Settings.AllowUniversalAccessFromFileURLs = true;
string root = Android.OS.Environment.ExternalStorageDirectory.ToString();
// Java.IO.File myDir = new Java.IO.File(root + "/WingsPdfs");
// myDir.Mkdir();
string path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
Java.IO.File file = new Java.IO.File(path, "WingsPdfGenerated.pdf");
FileOutputStream outs = new FileOutputStream(file);
outs.Write(customWebView.PdfStream.ToArray());
outs.Flush();
outs.Close();
try
{
Control.LoadUrl(string.Format("file:///android_asset/pdfjs/web/viewer.html?file={0}", file));
}
catch(Exception ex)
{
}
}
}
}
In the above code I hardcoded the location of the file but I want user to select particular location and save to the selected location.
Thank You
enter image description here

How to convert image to base64 string in Windows Phone?

I am developing a windows phone application in which I have to convert image to base64 string and I have to pass that string through Web Service. So I tried many Ways, but I cant able to send it as everytime I am getting error as "Target Invocation error". With this code I can choose the image from library but I cant send through web service.
I used the following code to covert the image:
private void photoChooserTask_Completed(object sender, PhotoResult e)
{
BitmapImage image = new BitmapImage();
image.SetSource(e.ChosenPhoto);
this.imageTribute.Source = image;
byte[] bytearray = null;
using (MemoryStream ms = new MemoryStream())
{
if (imageTribute.Source == null)
{
}
else
{
WriteableBitmap wbitmp = new WriteableBitmap((BitmapImage)imageTribute.Source);
wbitmp.SaveJpeg(ms, 40, 40, 0, 82);
bytearray = ms.ToArray();
}
}
strimage = Convert.ToBase64String(bytearray);
}
So please if anyone knows about that, help me out. Thanx in advance.
EDIT
void uploadphoto()
{
WebClient webClient1 = new WebClient();
webClient1.DownloadStringCompleted += new DownloadStringCompletedEventHandler(webClient1_DownloadStringCompleted);
webClient1.DownloadStringAsync(new Uri("Web Service"));
}
void webClient1_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
var rootobject1 = JsonConvert.DeserializeObject<RootObject1>(e.Result);
int error = rootobject1.response.errorFlag;
string message = rootobject1.response.msg;
if (error == 0)
{
MessageBox.Show(message);
}
else
{
MessageBox.Show(message);
}
}
public class Response1
{
public int errorFlag { get; set; }
public string msg { get; set; }
public List<string> uploadedImageNames { get; set; }
}
public class RootObject1
{
public Response1 response { get; set; }
}
private void ImageUpload(object sender, RoutedEventArgs e)
{
//MessageBoxResult mb = MessageBox.Show("Select the mode of uploading the picture", "", MessageBoxButton.OKCancel);
Popup popup = new Popup();
photoSelection photo = new photoSelection();
popup.Child = photo;
popup.IsOpen = true;
photo.camera.Click += (s, args) =>
{
photoCameraCapture.Show();
popup.IsOpen = false;
};
photo.library.Click += (s, args) =>
{
photoChooserTask.Show();
popup.IsOpen = false;
};
}
EDIT
Here I uploaded the stack trace of my error. So please check and reply me.
A Target Invocation Exception error tells you that the application crashed while invoking a method which could be many things. The real error is in the InnerException.
Look at the InnerException property of the TargetInvocationException object. This will show you the stack trace and the actual error thrown.
Get your file into stream either from resource or from isolatedStorage
//getting file from resource
var resource = Application.GetResourceStream(new Uri("image.jpg", UriKind.Relative));
//get Stream Data
StreamReader streamReader = new StreamReader(resource.Stream);
//initializing bytearray to stream length
byte[] imageData = new byte[streamReader.Length];
//wriing from stream to imagdata
streamReader.Read(imageData, 0, imageData.Length);
streamReader.Close();
Use isolatedStorageFile to read from isolated storage
now you have your image data in imageData and to convert it into base64 use:
var baseString = Convert.ToBase64String(imageData);

save image locally & display windows phone 7

I'm trying to implement an app of news (feedrss) by using WP7 i've tried this solution , but it does'nt work for me , here is my code :
namespace PhoneApp1
{
public partial class MainPage : PhoneApplicationPage
{
public MainPage()
{
InitializeComponent();}
private void Go_Click(object sender, RoutedEventArgs e)
{
WebClient _client = new WebClient();
_client.DownloadStringCompleted += Feed;
Location.Text = "http://www.aufaitmaroc.com/feeds/ma-vie.xml";
_client.DownloadStringAsync(new Uri((Location.Text)));
InitializeComponent();
}
private void Feed(object Sender, DownloadStringCompletedEventArgs e)
{
XElement _xml;
try
{
if (!e.Cancelled)
{
_xml = XElement.Parse(e.Result);
List<FeedItem> l = new List<FeedItem>();
foreach (XElement value in _xml.Elements("channel").Elements("item"))
{
FeedItem _item = new FeedItem();
_item.Title = value.Element("title").Value;
_item.enclosure = value.Element("enclosure").Attribute("url").Value;
_item.Description = Regex.Replace(value.Element("description").Value,
#"<(.|\n)*?>", String.Empty);
_item.Link = value.Element("link").Value;
_item.Guid = value.Element("guid").Value;
_item.Published = DateTime.Parse(value.Element("pubDate").Value);
l.Add(_item);
HttpWebRequest reqest1 = (HttpWebRequest)WebRequest.Create(_item.enclosure);
reqest1.BeginGetResponse(DownloadImageCallback, reqest1);
Thread.Sleep(1000);
WebClient client = new WebClient();
client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
client.OpenReadAsync(new Uri(_item.enclosure), client);
}
listBox.ItemsSource = l;
}
}
catch
{
}
}
IsolatedStorageFile MyStore = IsolatedStorageFile.GetUserStoreForApplication();
void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
var resInfo = new StreamResourceInfo(e.Result, null);
var reader = new StreamReader(resInfo.Stream);
byte[] contents;
using (BinaryReader bReader = new BinaryReader(reader.BaseStream))
{
contents = bReader.ReadBytes((int)reader.BaseStream.Length);
}
IsolatedStorageFileStream stream = MyStore.CreateFile("10.jpg");
stream.Write(contents, 0, contents.Length);
stream.Close();
}
void DownloadImageCallback(IAsyncResult result)
{
HttpWebRequest req1 = (HttpWebRequest)result.AsyncState;
HttpWebResponse responce = (HttpWebResponse)req1.EndGetResponse(result);
Stream s = responce.GetResponseStream();
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
string directory = "Imagestest";
if (!MyStore.DirectoryExists(directory))
{
MyStore.CreateDirectory(directory);
IsolatedStorageFileStream stream = MyStore.CreateFile("10.jpg");
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
using (var isoFileStream = myIsolatedStorage.CreateFile(directory + "//ANALYSE_10052013095620.jpg"))
{
var bitimage = new BitmapImage();
var wb = new WriteableBitmap(bitimage);
var width = wb.PixelWidth;
var height = wb.PixelHeight;
// bitimage.SetSource = isoFileStream;
image1.Source = bitimage;
System.Windows.Media.Imaging.Extensions.SaveJpeg(wb, isoFileStream, width, height, 0, 100);
}
}
}
else
{
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (myIsolatedStorage.FileExists(directory + "//ANALYSE_10052013095620.jpg"))
{
myIsolatedStorage.DeleteFile(directory + "//ANALYSE_10052013095620.jpg");
}
using (var isoFileStream = myIsolatedStorage.CreateFile(directory + "//ANALYSE_10052013095620.jpg"))
{
var bitimage = new BitmapImage();
var wb = new WriteableBitmap(bitimage);
var width = wb.PixelWidth;
var height = wb.PixelHeight;
System.Windows.Media.Imaging.Extensions.SaveJpeg(wb, isoFileStream, width, height, 0, 100);
}
}
}
});
}
private void listBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
FeedItem currentFeedItem = (FeedItem)listBox.SelectedItem;
PhoneApplicationService.Current.State["FeedItem"] = currentFeedItem;
}
When i run this project , nothing's happend , it does'nt create any folder ,when i stop the internet , images doesnt display anymore.
If you need image caching in your app, I can suggest JetImageLoader library for you
Features:
Caching in memory (so it will work very fast with lists, grids, etc)
Caching is IsolatedStorageFile (to prevent reloading each time)
Fully asynchronous (no lags)
Usage via XAML Binding Converter, you do not have to change your code, just declare converter for Image
But it supports only Windows Phone 8+
I am authour of that library, so if you got any questions, please write to me here or create an issue on github
If you want to save image locally and the display image from locally, then try this sample
http://code.msdn.microsoft.com/wpapps/CSWP8ImageFromIsolatedStora-8dcf8411, on WP 8 it's works fine.

Get stream from absolute Uri

I'm working with Windows Phone 7 and I have a very difficult problem. Please help me !
I want to get a stream form an absolute uri (from web) of a png image. But GetResourceStream method work only with relative uri. Then I found imagetool form http://imagetools.codeplex.com/ but to now my problem is not still solved.
Could anyone give me a solution ?
How about using HttpWebRequest and HttpWebResponse?
var uri = new Uri("http://chriskoenig.net/wp-content/uploads/2011/04/givecamp_125125_ad.jpg", UriKind.Absolute);
HttpWebRequest request = HttpWebRequest.Create(uri) as HttpWebRequest;
request.BeginGetResponse((ar) =>
{
var response = request.EndGetResponse(ar);
Dispatcher.BeginInvoke(() =>
{
using (var stream = response.GetResponseStream())
{
var image = new BitmapImage();
image.SetSource(stream);
MyImage.Source = image;
}
});
}, null);
Try this simple Code Image stream from Absolute url and store to isolated storage
namespace eQuadrigaWP7
{
public class ItemViewModel : INotifyPropertyChanged
{
private string _imgURL;
public string imgURL
{
get
{
return _imgURL;
}
set
{
if (value != _imgURL)
{
_imgURL = value;
}
}
}
private BitmapImage _Image;
public BitmapImage Iimage
{
get
{
return _Image;
}
set
{
if (value != _Image)
{
_Image = value;
}
}
}
public void LoadIimage()
{
if (this.imgURL == null) throw new Exception("Error equadriga log");
HttpWebRequest downloadthumbnailrequest = (HttpWebRequest)WebRequest.Create(new Uri(this._imgURL)); ///this is main
DownloadThumbNailState thumbnailState = new DownloadThumbNailState();
thumbnailState.AsyncRequest = downloadthumbnailrequest;
downloadthumbnailrequest.BeginGetResponse(new AsyncCallback(HandleThumNailDownLoadResponse),
thumbnailState);
}
private void HandleThumNailDownLoadResponse(IAsyncResult asyncResult)
{
DownloadThumbNailState thumbnailState = (DownloadThumbNailState)asyncResult.AsyncState;
HttpWebRequest downloadthumbnailrequest = (HttpWebRequest)thumbnailState.AsyncRequest;
thumbnailState.AsyncResponse = (HttpWebResponse)downloadthumbnailrequest.EndGetResponse(asyncResult);
Stream imageStream = thumbnailState.AsyncResponse.GetResponseStream();
byte[] b = new byte[imageStream.Length];
imageStream.Read(b,0,Convert.ToInt32(imageStream.Length));
imageStream.Close();
MemoryStream ms = new MemoryStream(b);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(ms);
String tempJPEG = "logo.jpg";
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (myIsolatedStorage.FileExists(tempJPEG))
{
myIsolatedStorage.DeleteFile(tempJPEG);
}
IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile(tempJPEG);
WriteableBitmap wb = new WriteableBitmap(bmp);
Extensions.SaveJpeg(wb, fileStream, wb.PixelWidth, wb.PixelHeight, 0, 85);
fileStream.Close();
this.Iimage = bmp;
}
});
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String propertyName)
{
if (null != PropertyChanged)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public class DownloadThumbNailState
{
public HttpWebRequest AsyncRequest { get; set; }
public HttpWebResponse AsyncResponse { get; set; }
}
}
}
ItemViewModel imageitem = new ItemViewModel();
imageitem.imgURL = "http://www.yoursite.in/bilder/9780199738663/titel.jpg";
imageitem.LoadIimage();
Try this one,
BitmaiImage bmp=new BitmaiImage();
Image image=new Image();
Uri url = new Uri("http://Ur url", UriKind.Absolute);
HttpWebRequest reqest = (HttpWebRequest)WebRequest.Create(url);
reqest.BeginGetResponse(DownloadImageCallback, reqest);
void DownloadImageCallback(IAsyncResult result)
{
HttpWebRequest req = (HttpWebRequest)result.AsyncState;
HttpWebResponse responce = (HttpWebResponse)req.EndGetResponse(result);
Stream s = responce.GetResponseStream();
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
bmp.SetSource(s);
image.Source=bmp;
});
}

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