我有一个带有指定网址的网络图片，可以在浏览器中浏览。
我试图从网址中检索它，当程序转到bitmapImage.SetSource(ms);时，我得到一个异常“
ex = {System.Exception: The component cannot be found. (Exception from HRESULT: 0x88982F50)
at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
at MS.Internal.XcpImports.BitmapSource_SetSource(BitmapSource bitmapSource, CValue& byteStream)
at System.Wi...
” 我在stackoverflow上搜索了其他问题...但没有帮助。任何人都可以帮助我吗？
字节数组确实有数据，在运行时调试中，它返回imageByteArray = {byte [1227]};我的选择是将字节数组转换为BitmapImage时发生异常。
在httpclient包装器类中：
public static async Task<Byte[]> GetWebImageByImageName(string ImageName)
{
//Uri imageServerUril = new Uri(ImageName);
var requestMessage = new HttpRequestMessage(HttpMethod.Get, ImageName);
var responseMessage = await client.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead);
var responseData = await responseMessage.Content.ReadAsByteArrayAsync();
return responseData;
}
在视图模型中：
private async void ReadArticleList(int pageNumber)
{
string webURL = "http://....."; // the web URL is no problem
try
{
byte[] imageByteArray = await CollectionHttpClient.GetWebImageByImageName(webURL);//
//Convert it to BitmapImage
using (MemoryStream ms = new MemoryStream(imageByteArray))
{
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.CreateOptions = BitmapCreateOptions.DelayCreation;
bitmapImage.SetSource(ms); // the exception got here
item.BitImage = bitmapImage;
}
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;
}
}
* for Detail *
文章模型如下：
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");
}
}
}
public List<string> ImagePathList = new List<string>();
public BitmapImage BitImage = new BitmapImage();
private string _firstImage;
public string FirstImage
{
get
{
return _firstImage;
}
set
{
if (_firstImage != value)
{
_firstImage = value;
NotifyPropertyChanged();
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChangedEventHandler handler = PropertyChanged;
if (null != handler)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
答案 0 :(得分：2)
如果您只想在不保存的情况下显示远程服务器中的图像，请执行以下操作：
imageControl1.Source = new BitmapImage(new Uri("http://delisle.saskatooncatholic.ca/sites/delisle.saskatooncatholic.ca/files/sample-1.jpg", UriKind.Absolute));
如果要将图像保存到IsolatedStorage，可以执行以下操作：
WebClient webClientImg = new WebClient();
webClientImg.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
webClientImg.OpenReadAsync(new Uri("http://delisle.saskatooncatholic.ca/sites/delisle.saskatooncatholic.ca/files/sample-1.jpg", UriKind.Absolute));
void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
isSpaceAvailable = IsSpaceIsAvailable(e.Result.Length);
if (isSpaceAvailable)
{
SaveToJpeg(e.Result);
}
else
{
MessageBox.Show("You are running low on storage space on your phone. Hence the image will be loaded from the internet and not saved on the phone.", "Warning", MessageBoxButton.OK);
}
}
检查IsolatedStorage空间是否可用的功能，否则它将不会下载图像。
private bool IsSpaceIsAvailable(long spaceReq)
{
using (var store = IsolatedStorageFile.GetUserStoreForApplication())
{
long spaceAvail = store.AvailableFreeSpace;
if (spaceReq > spaceAvail)
{
return false;
}
return true;
}
}
如果空间可用，请使用以下函数将图像另存为IsolatedStorage：
private void SaveToJpeg(Stream stream)
{
using (IsolatedStorageFile iso = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream isostream = iso.CreateFile("image1.jpg"))
{
BitmapImage bitmap = new BitmapImage();
bitmap.SetSource(stream);
WriteableBitmap wb = new WriteableBitmap(bitmap);
// Encode WriteableBitmap object to a JPEG stream.
Extensions.SaveJpeg(wb, isostream, wb.PixelWidth, wb.PixelHeight, 0, 85);
isostream.Close();
LoadImageFromIsolatedStorage(); //Load recently saved image into the image control
}
}
}
从IsolatedStorage加载图像控件：
private void LoadImageFromIsolatedStorage()
{
byte[] data;
try
{
using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream isfs = isf.OpenFile("image1.jpg", FileMode.Open, FileAccess.Read))
{
data = new byte[isfs.Length];
isfs.Read(data, 0, data.Length);
isfs.Close();
}
}
MemoryStream ms = new MemoryStream(data);
BitmapImage bi = new BitmapImage();
bi.SetSource(ms);
imageControl1.Source = bi;
}
catch
{
}
}
从Google搜索中随机拍摄的图片。对图像的信任归于所有者。
希望这会有所帮助。 ：）
答案 1 :(得分：1)
@Mark，你是对的，这可以根据你的建议运作。
我认为问题是如果我使用下面的代码，我得到的字节数组是字节[1227]
var requestMessage = new HttpRequestMessage(HttpMethod.Get, ImageName);
var responseMessage = await client.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead);
var responseData = await responseMessage.Content.ReadAsByteArrayAsync();
return responseData;
如果我使用var byteArray = await client.GetByteArrayAsync(ImageName);，则字节数组大小为byte [5996]
我不知道为什么会这样，但Mark的解决方案有效。
我的所有代码如下：
// 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;
}
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;
}
}
模型是：
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));
}
}
}
答案 2 :(得分：0)
首先，如果您有网址，您可以将网址提供给绑定参数，它会自动显示图像，或者您是否要下载图像并保存图像。然后显示它，所以这里是字节到图像的代码＆amp;图像到字节。
{
BitmapImage image = new BitmapImage();
MemoryStream ms = new MemoryStream();
WriteableBitmap wb = new WriteableBitmap(image);
wb.SaveJpeg(ms, image.PixelWidth, image.PixelHeight, 0, 100);
imageBytes = ms.ToArray();
}
使用它来保存图像，因为我正在使用我的代码。