@Mark , you are correct, this works according to what you suggest.
i think the problem is if i used code below, i got the byte array is byte[1227]
var requestMessage = new HttpRequestMessage(HttpMethod.Get, ImageName);
var responseMessage = await client.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead);
var responseData = await responseMessage.Content.ReadAsByteArrayAsync();
return responseData;
and if i use var byteArray = await client.GetByteArrayAsync(ImageName);
the byte array size is byte[5996]
i do not know why this happens, but Mark's solution works.
all my code is as below:
in a MVVM pattern
// get image from URL, ImageName is an absolute Url
public static async Task<BitmapImage> GetWebImageByImageName(string ImageName)
{
//Uri imageServerUril = new Uri(ImageName);
var byteArray = await client.GetByteArrayAsync(ImageName);
//Convert byte array to BitmapImage
BitmapImage bitmapImage;
using (MemoryStream ms = new MemoryStream(byteArray))
{
bitmapImage = new BitmapImage();
bitmapImage.SetSource(ms);
}
return bitmapImage;
}
in the ViewModel
public void LoadPage(int pageNumber)
{
if (pageNumber == 1)
{
this.ArticleCollection.Clear();
}
IsLoading = true;
ReadArticleList(pageNumber);
}
private async void ReadArticleList(int pageNumber)
{
try
{
List<Article> articleList = new List<Article>();
articleList = await CollectionHttpClient.GetArticlesByPageAsync(pageNumber);
foreach (var item in articleList)
{
item.BitImage = await CollectionHttpClient.GetWebImageByImageName(item.ImagePathList[0]);
this.ArticleCollection.Add(item);
}
IsLoading = false;
}
catch(Exception ex)
{
if (ex.HResult == -2146233088 && ex.Message.Equals("Response status code does not indicate success: 404 ()."))
{
MessageBox.Show("The network is not set right. Internet cannot be accessed.");
}
else
{
MessageBox.Show("sorry, no data.");
}
IsLoading = false;
}
}
Model is:
public class Article : INotifyPropertyChanged
{
private long _Id;
public long ID
{
get { return _Id; }
set
{
if (_Id != value)
{
_Id = value;
NotifyPropertyChanged("ID");
}
}
}
private string _subject;
public string Subject
{
get
{
return _subject;
}
set
{
if (_subject != value)
{
_subject = value;
NotifyPropertyChanged("Subject");
}
}
}
private string _words;
public string Words
{
get
{
return _words;
}
set
{
if (_words != value)
{
_words = value;
NotifyPropertyChanged("Words");
}
}
}
private DateTime _publishDate;
public DateTime PublishDate
{
get
{ return _publishDate; }
set
{
if (_publishDate != value)
{
_publishDate = value;
NotifyPropertyChanged("PublishDate");
}
}
}
private ObservableCollection<string> _imagePathList = new ObservableCollection<string>();
public ObservableCollection<string> ImagePathList
{
get { return this._imagePathList; }
set
{
if (this._imagePathList != value)
{
this._imagePathList = value;
// I'm going to assume you have the NotifyPropertyChanged
// method defined on the view-model
this.NotifyPropertyChanged();
}
}
}
BitmapImage _image;
public BitmapImage BitImage
{
get
{
return _image;
}
set
{
if (ImagePathList.Any())
{
value = new BitmapImage(new Uri(ImagePathList.FirstOrDefault(), UriKind.RelativeOrAbsolute));
_image = value;
}
}
}
private Uri _firstImage;
public Uri FirstImage
{
get
{
return _firstImage;
}
set
{
if (_firstImage != value)
{
_firstImage = value;
NotifyPropertyChanged("FirstImage");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChangedEventHandler handler = PropertyChanged;
if (null != handler)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}