/// <summary>
/// 将实体类改变为ViewModel类.
/// </summary>
public static ComposePhotoViewModel CreateFromModel(Photo model)
{
ComposePhotoViewModel viewModel = new ComposePhotoViewModel()
{
Name = model.Name,
MediaStream = model.ThumbnailStream,
PhotoDuration = (int)(model.PhotoDuration.TotalSeconds)
};
if (model.Transition != null)
{
viewModel.Transition = model.Transition;
viewModel.TransitionDuration = (int)(model.Transition.TransitionDuration.TotalSeconds);
}
return viewModel;
}
/// <summary>
/// 读取指定的story.
/// </summary>
/// <param name="storyName">story名称.</param>
/// <param name="userStore">如果参数为null, 创建一个新的.</param>
internal static void ReadStoryFile(string storyName, IsolatedStorageFile userStore = null)
{
if (userStore == null)
{
userStore = IsolatedStorageFile.GetUserStoreForApplication();
}
using (IsolatedStorageFileStream fileStream = userStore.OpenFile(storyName + ".xml", System.IO.FileMode.Open))
{
XDocument xdoc = XDocument.Load(fileStream);
var picturesLibrary = new MediaLibrary().Pictures;
// Load all photos.
foreach (XElement photoElement in xdoc.Root.Elements())
{
try
{
Photo photo = new Photo()
{
Name = photoElement.Attribute("Name").Value,
};
string photoDurationString = photoElement.Attribute("PhotoDuration").Value;
int photoDuration = int.Parse(photoDurationString);
photo.PhotoDuration = TimeSpan.FromSeconds(photoDuration);
XElement transitionElement = photoElement.Element("Transition");
if (transitionElement != null)
{
photo.Transition = TransitionBase.Load(photoElement.Element("Transition"));
}
Picture picture = picturesLibrary.Where(p => p.Name == photo.Name).FirstOrDefault();
if (picture == null)
{
// 如果找不到原文件，可能已经被删除了
// TODO: 我们需要记录错误吗? 我们是继续下一个图片还是抛出异常?
continue;
}
photo.ThumbnailStream = picture.GetThumbnail();
App.MediaCollection.Add(photo);
}
catch
{
// TODO: 我们需要记录错误吗? 我们是继续下一个图片还是抛出异常?
continue;
}
}
}
}
private void OKButton_Click(object sender, System.EventArgs e)
{
this.StoreSelection();
// 添加所有选中的图片到App.MediaCollection.
foreach (ChoosePhotoViewModel photo in this._selectedPhotos)
{
Photo photoModel = new Photo()
{
Name = photo.Name,
ThumbnailStream = photo.MediaStream,
PhotoDuration = TimeSpan.FromSeconds(5d),
Transition = TransitionFactory.CreateDefaultTransition()
};
if (!App.MediaCollection.Contains(photoModel))
{
App.MediaCollection.Add(photoModel);
}
}
// 回到调用页面
this.NavigationService.GoBack();
}
/// <summary>
/// 从XNA媒体库中获取的原始图像。
/// 并调整其大小的目标分辨率。
/// 调用BitmapHelper.GetResizedImage内部。
/// 不同的是此方法返回WriteableBitmap的，
/// 而BitmapHelper.GetResizedImage返回流。
/// 此方法还设置Photo.ResizedImage和Photo.ResizedImageStream。
/// </summary>
/// <param name="photo">图片需要被重设.</param>
/// <returns>一个WriteableBitmap图片需要被重新设置.</returns>
private WriteableBitmap GetResizedImage(Photo photo)
{
Stream resizedImageStream = BitmapHelper.GetResizedImage(photo.Name);
WriteableBitmap resizedImage = new WriteableBitmap(BitmapHelper.ResizedImageWidth, BitmapHelper.ResizedImageHeight);
resizedImage.SetSource(resizedImageStream);
photo.ResizedImageStream = resizedImageStream;
photo.ResizedImage = resizedImage;
return resizedImage;
}