我有一个应用程序可以拍摄照片，将它们转换为字节数组并将它们本地保存在独立存储中。然后它将它们读出并将它们转换回 BitmapImage。
但是，我似乎无法在 ListBox 中显示图像。我正在使用我在另一个完美运行的页面中的相同代码。
BitmapImage 中有一个图像，但据我所知，这就是我所知道的。该图像是否合法，我不知道也不知道如何检查。
任何想法将不胜感激。
请参阅下面的代码
转换图像
public byte[] ImageToBytes(BitmapImage img)
{
using (MemoryStream ms = new MemoryStream())
{
WriteableBitmap btmMap = new WriteableBitmap(img.PixelWidth, img.PixelHeight);
// write an image into the stream
Extensions.SaveJpeg(btmMap, ms, img.PixelWidth, img.PixelHeight, 0, 100);
return ms.ToArray();
}
}
public BitmapImage BytesToImage(byte[] bytes)
{
BitmapImage bitmapImage = new BitmapImage();
MemoryStream ms = new MemoryStream(bytes);
bitmapImage.SetSource(ms);
return bitmapImage;
}
带图像的类
public class NewItem
{
ObservableCollection<BitmapImage> images = new ObservableCollection<BitmapImage>();
[DataMember]
public ObservableCollection<BitmapImage> Images
{
get { return images; }
set { images = value; }
}
[DataMember]
public string Notes { get; set; }
[DataMember]
public string ItemID { get; set; }
}
保存到存储
public static void AddOrUpdateUnsavedItems(NewItem _item)
{
var store = IsolatedStorageFile.GetUserStoreForApplication();
List<NewItem> allunsaveditems = new List<NewItem>();
if (store.FileExists("unsaveditem"))
{
allunsaveditems.Add(_item);
allunsaveditems.AddRange(LoadUnsavedItemsFromIsolatedStorage());
store.DeleteFile("unsaveditem");
}
UnsavedRegisters.Clear();
foreach (NewItem ni in allunsaveditems)
{
StoredItem newUnsavedItem = new StoredItem();
newUnsavedItem.ItemID = ni.ItemID;
newUnsavedItem.Notes = ni.Notes;
foreach (BitmapImage bmp in ni.Images)
{
newUnsavedItem.ImageBytes.Add(newUnsavedItem.ImageToBytes(bmp));
}
UnsavedRegisters.Add(newUnsavedItem);
}
using (var stream = new IsolatedStorageFileStream("unsaveditem", FileMode.OpenOrCreate, FileAccess.Write, store))
{
DataContractSerializer dcs = new DataContractSerializer(typeof(List<StoredItem>));
dcs.WriteObject(stream, UnsavedRegisters);
}
}
从存储加载
public static List<NewItem> LoadUnsavedItemsFromIsolatedStorage()
{
List<NewItem> unsavedItems = new List<NewItem>();
try
{
var store = IsolatedStorageFile.GetUserStoreForApplication();
if (store.FileExists("unsaveditem"))
{
using (var stream = new IsolatedStorageFileStream("unsaveditem", FileMode.OpenOrCreate, FileAccess.Read, store))
{
if (stream.Length > 0)
{
DataContractSerializer dcs = new DataContractSerializer(typeof(List<StoredItem>));
List<StoredItem> storedItems = dcs.ReadObject(stream) as List<StoredItem>;
foreach (StoredItem si in storedItems)
{
NewItem ni = new NewItem();
ni.ItemID = si.ItemID;
ni.Notes = si.Notes;
foreach (byte[] imageBytes in si.ImageBytes)
{
ni.Images.Add(si.BytesToImage(imageBytes));
}
unsavedItems.Add(ni);
}
}
}
}
}
catch (Exception)
{
//MessageBox.Show("and error happened getting the unsaved items");
// handle exception
return null;
}
return unsavedItems;
}