我要脱掉头发，但在我这样做之前，我会尝试向你们寻求帮助......也许有人有同样的问题可以帮助我。
所以这是交易。我有一个名为SourceZoneSelect的LongListSelector定义如下：
<phone:LongListSelector x:Name="SourceZoneSelect" Grid.Row="2"
LayoutMode="Grid"
GridCellSize="160,160"
BorderThickness="0"
HorizontalContentAlignment="Stretch"
VerticalContentAlignment="Stretch"
Background="White"
Width="480" Foreground="Black"
ItemTemplate="{StaticResource DataTemplateContentZone}"
Style="{StaticResource LongListSelectorStyleContentZone}"
ScrollViewer.VerticalScrollBarVisibility="Visible" Margin="-2,0,0,0"/>
ItemTemplate是一个DataTemplateSelector：
<DataTemplate x:Key="DataTemplateContentZone">
<local:ContentZoneTemplateSelector Content="{Binding}" VerticalAlignment="Top" HorizontalAlignment="Right">
...
<local:ContentZoneTemplateSelector.PhotoWebSelect>
<DataTemplate>
<Grid Height="158" Width="158">
<Button BorderThickness="0" Style="{StaticResource ButtonStyleStyle}" Width="158" Height="158" toolkit:TiltEffect.IsTiltEnabled="True" Click="Button_SourceZone_Select_Click">
<Grid HorizontalAlignment="Left" Height="158">
<Rectangle Fill="{StaticResource StayfilmThirdColor}" HorizontalAlignment="Left" Height="158" Stroke="Black" VerticalAlignment="Top" Width="158"/>
<Image x:Name="img" Stretch="UniformToFill" Width="158" Height="158" Source="{Binding Thumb}" Tag="{Binding ImgUrl}"/>
<Grid x:Name="GridSelected" Tag="{Binding idMedia}" HorizontalAlignment="Right" Height="35" VerticalAlignment="Top" Width="35" Background="#FF0E9B00" Visibility="{Binding selected, Converter={StaticResource PhotoSelectedConverter}}">
<Path Data="F1M0.555,6.585L0.089,6.077C-0.036,5.942,-0.029,5.73,0.107,5.605L1.464,4.344C1.525,4.287 1.606,4.255 1.689,4.255 1.785,4.255 1.871,4.293 1.935,4.361L5.661,8.373 12.07,0.126C12.134,0.047 12.23,0 12.334,0 12.41,0 12.481,0.024 12.54,0.07L14.003,1.206C14.073,1.26 14.117,1.339 14.128,1.429 14.141,1.518 14.116,1.606 14.061,1.674L5.826,12.263z" Fill="White" Margin="0" UseLayoutRounding="False" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Grid>
</Grid>
</Button>
</Grid>
</DataTemplate>
</local:ContentZoneTemplateSelector.PhotoWebSelect>
<local:ContentZoneTemplateSelector.VideoSelect>
<DataTemplate>
<Grid Height="158" Width="158">
<Button BorderThickness="0" Style="{StaticResource ButtonStyleStyle}" Width="Auto" Height="Auto" toolkit:TiltEffect.IsTiltEnabled="True" Click="Button_SourceZone_Select_Click">
<Grid Height="158" Width="158">
<Image x:Name="videoThumb" Stretch="Fill" Width="158" Height="158" Source="{Binding VideoThumbUrl}"/>
<Image HorizontalAlignment="Center" Height="80" VerticalAlignment="Center" Width="80" Source="/Assets/Dark/feature.video.png"/>
<Grid x:Name="GridSelected" Tag="{Binding idMedia}" HorizontalAlignment="Right" Height="35" VerticalAlignment="Top" Width="35" Background="#FF0E9B00" Visibility="{Binding Selected, Converter={StaticResource VideoSelectedConverter}}">
<Path Data="F1M0.555,6.585L0.089,6.077C-0.036,5.942,-0.029,5.73,0.107,5.605L1.464,4.344C1.525,4.287 1.606,4.255 1.689,4.255 1.785,4.255 1.871,4.293 1.935,4.361L5.661,8.373 12.07,0.126C12.134,0.047 12.23,0 12.334,0 12.41,0 12.481,0.024 12.54,0.07L14.003,1.206C14.073,1.26 14.117,1.339 14.128,1.429 14.141,1.518 14.116,1.606 14.061,1.674L5.826,12.263z" Fill="White" Margin="0" UseLayoutRounding="False" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Grid>
</Grid>
</Button>
</Grid>
</DataTemplate>
</local:ContentZoneTemplateSelector.VideoSelect>
...
</local:ContentZoneTemplateSelector>
</DataTemplate>
还有2个值转换器：
in .xaml file
<phone:PhoneApplicationPage.Resources>
<local:PhotoSelectedConverter x:Name="PhotoSelectedConverter"/>
<local:VideoSelectedConverter x:Name="VideoSelectedConverter"/>
in .cs file
public class PhotoSelectedConverter : IValueConverter
{
public object Convert(object value, Type typeName, object parameter, CultureInfo language)
{
bool selected = (bool)value;
if (!selected)
{
return "Collapsed";
}
else
{
return "Visible";
}
}
public object ConvertBack(object value, Type typeName, object parameter, CultureInfo language)
{
return DependencyProperty.UnsetValue;
}
}
public class VideoSelectedConverter : IValueConverter
{
public object Convert(object value, Type typeName, object parameter, CultureInfo language)
{
double selected = (double)value;
if (selected == 0.0)
{
return "Collapsed";
}
else
{
return "Visible";
}
}
public object ConvertBack(object value, Type typeName, object parameter, CultureInfo language)
{
return DependencyProperty.UnsetValue;
}
}
这是直接管理名为GridSelected的Grid的代码，该Grid在datatemplate上定义，就好像绑定的项目 - ＆gt; selected属性为false，GridSelected应该是Collapsed，如果为true，那么它应该是Visible ......
这是代码：
... List<StayClassLibrary.Media> medias = await Media.GetMediasByAlbum(albmLst, App.Current.AppUser, App.Current.WSConfig);
if (selectedSourceZone.Count > 0)
{
selectedSourceZone.Clear();
}
selectedSourceZone = null;
selectedSourceZone = new ObservableCollection<IDisposable>();
SourceZoneSelect.ClearValue(LongListSelector.DataContextProperty);
SourceZoneSelect.ClearValue(LongListSelector.ItemsSourceProperty);
SourceZoneSelect.UpdateLayout();
popupSourceZone_Select.UpdateLayout();
GridSourceZoneSelect.UpdateLayout();
if (medias.Count == 0)
{
NoImagesFound.Visibility = System.Windows.Visibility.Visible;
}
else
{
NoImagesFound.Visibility = System.Windows.Visibility.Collapsed;
//TODO criar PictureItems
foreach (StayClassLibrary.Media item in medias)
{
BitmapImage b = new BitmapImage();
b.UriSource = new Uri(item.thumbnail, UriKind.RelativeOrAbsolute);
b.ImageFailed += b_ImageFailed;
bool found = false;
foreach (var media in selectedContentZone)
{
if(media.GetType() == typeof(PictureItemWeb))
{
if(((PictureItemWeb)media).idMedia == item.idMidia)
{
if (!selectedSourceMedias.Contains(item.idMidia.ToString()))
{
found = true;
}
break;
}
}
else if(media.GetType() == typeof(VideoItem))
{
if (((VideoItem)media).idMedia == item.idMidia)
{
if (!selectedSourceMedias.Contains(item.idMidia.ToString()))
{
found = true;
}
break;
}
}
}
if (item.type == "image")
{
selectedSourceZone.Insert(0, new PictureItemWeb
{
Thumb = b,
Pic = new BitmapImage(new Uri(item.source, UriKind.RelativeOrAbsolute)),
dateBinary = DateTime.Now.ToBinary(),
idAlbum = item.idAlbum,
idMedia = item.idMidia,
ImgUrl = item.source,
ThumbUrl = item.thumbnail,
selected = false,
selectable = true,
added = found,
cancellationToken = new CancellationTokenSource()
});
}
else if (item.type == "video")
{
selectedSourceZone.Insert(0, new VideoItem
{
Thumb = b,
dateBinary = DateTime.Now.ToBinary(),
idAlbum = item.idAlbum,
idMedia = item.idMidia,
VideoUrl = item.source,
VideoThumbUrl = item.thumbnail,
Selected = 0.0,
selectable = true,
added = found,
cancellationToken = new CancellationTokenSource()
});
}
b = null;
}
if (selectedSourceZone.Count > 0)
{
Storyboard sb = new Storyboard();
DoubleAnimation fadein = new DoubleAnimation();
fadein.From = 0.0;
fadein.To = 1.0;
fadein.Duration = new Duration(TimeSpan.FromSeconds(0.35));
Storyboard.SetTarget(fadein, SourceZoneSelect);
Storyboard.SetTargetProperty(fadein, new PropertyPath("Opacity"));
sb.Children.Add(fadein);
sb.Begin();
SourceZoneSelect.ItemsSource = null;
SourceZoneSelect.ClearValue(LongListSelector.DataContextProperty);
SourceZoneSelect.ClearValue(LongListSelector.ItemsSourceProperty);
SourceZoneSelect.ItemsSource = selectedSourceZone;
// *1
foreach (var item in selectedSourceZone)
{
if(item.GetType() == typeof(PictureItemWeb))
{
if(selectedSourceMedias.Contains(((PictureItemWeb)item).idMedia.ToString()))
{
((PictureItemWeb)item).selected = true;
}
}
else if (item.GetType() == typeof(VideoItem))
{
if (selectedSourceMedias.Contains(((VideoItem)item).idMedia.ToString()))
{
((VideoItem)item).Selected = 1.0;
}
}
UpdateSelectedState(SourceZoneSelect, item); // *2
}
}
else
{
NoImagesFound.Visibility = System.Windows.Visibility.Visible;
Storyboard sb = new Storyboard();
DoubleAnimation fadein = new DoubleAnimation();
fadein.From = 0.0;
fadein.To = 1.0;
fadein.Duration = new Duration(TimeSpan.FromSeconds(0.35));
Storyboard.SetTarget(fadein, NoImagesFound);
Storyboard.SetTargetProperty(fadein, new PropertyPath("Opacity"));
sb.Children.Add(fadein);
sb.Begin();
}
}
* 1它应该激活IValueConverter并且它没有...我在那里有一个断点，它永远不会通过那里。
* 2此函数UpdateSelectedState（）我创建了尝试手动修复和更新每个媒体的GridSelected可见性
private void UpdateSelectedState(DependencyObject targetElement, object item)
{
var count = VisualTreeHelper.GetChildrenCount(targetElement);
if (count == 0)
return;
for (int i = 0; i < count; i++)
{
var child = VisualTreeHelper.GetChild(targetElement, i);
if (child is Button)
{
Button targetItem = (Button)child;
if (item.GetType() == typeof(PictureItemWeb))
{
if (((PictureItemWeb)targetItem.DataContext).idMedia == ((PictureItemWeb)item).idMedia)
{
var g = targetItem.FindName("GridSelected");
if (((Guid)((Grid)g).Tag) == ((PictureItemWeb)item).idMedia)
{
if (((PictureItemWeb)item).selected)
{
((Grid)g).Visibility = System.Windows.Visibility.Visible;
}
else
{
((Grid)g).Visibility = System.Windows.Visibility.Collapsed;
}
}
return;
}
}
else if (item.GetType() == typeof(VideoItem))
{
if (((VideoItem)targetItem.DataContext).idMedia == ((VideoItem)item).idMedia)
{
var g = targetItem.FindName("GridSelected");
if (((VideoItem)item).Selected == 1.0)
{
((Grid)g).Visibility = System.Windows.Visibility.Visible;
}
else
{
((Grid)g).Visibility = System.Windows.Visibility.Collapsed;
}
return;
}
return;
}
}
else
{
UpdateSelectedState(child, item);
}
}
}
这是我点击图片时的代码。 （它所做的只是将selected属性更改为true / false并显示/隐藏单击项目的GridSelected：
private void Button_SourceZone_Select_Click(object sender, RoutedEventArgs e)
{
var media = ((Button)sender).DataContext;
if (media.GetType() == typeof(PictureItemWeb))
{
int index = selectedSourceZone.IndexOf(((PictureItemWeb)((Button)sender).DataContext));
if (index != -1)
{
((PictureItemWeb)selectedSourceZone.ElementAt(index)).selected = !((PictureItemWeb)selectedSourceZone.ElementAt(index)).selected;
}
var g = ((Button)sender).FindName("GridSelected");
if (((PictureItemWeb)selectedSourceZone.ElementAt(index)).selected)
{
((Grid)g).Visibility = System.Windows.Visibility.Visible;
}
else
{
((Grid)g).Visibility = System.Windows.Visibility.Collapsed;
}
}
else if (media.GetType() == typeof(VideoItem))
{
int index = selectedSourceZone.IndexOf(((VideoItem)((Button)sender).DataContext));
if (index != -1)
{
((VideoItem)selectedSourceZone.ElementAt(index)).Selected = (((VideoItem)selectedSourceZone.ElementAt(index)).Selected == 0.0) ? 1.0 : 0.0;
}
var g = ((Button)sender).FindName("GridSelected");
if (((VideoItem)selectedSourceZone.ElementAt(index)).Selected == 1.0)
{
((Grid)g).Visibility = System.Windows.Visibility.Visible;
}
else
{
((Grid)g).Visibility = System.Windows.Visibility.Collapsed;
}
}
}
好的所有代码现在都在这里。
我唯一没有发布的是当我点击确认选择时的功能..它所做的就是将媒体的ID添加到列表中，如：
selectedSourceMedias.Add(((PictureItemWeb)item).idMedia.ToString());
然后关闭弹出窗口并将longlistselector设置为null。
所以当我点击按钮再次显示列表时。它重新创建了整个列表！如我发布的第一个代码所示（它请求媒体，再次将longlistselector设置为null并重新创建longlist Items（PictureWeb和VideoItem都是IDisposable）。
最后！这让我很生气。我已经调试过，并且它应该完美无缺！但情况如下：
所以我觉得某个地方有一个内部错误，可以保存具有相同名称的数据模板（＆＃34; GridSelected＆＃34;）
我知道这可能会让你有点头疼但是......请尽量帮助我！
如果您遇到类似问题以及如何解决问题，请告诉我。
提前谢谢大家!!!
答案 0 :(得分：1)
我找到了问题的解决方案......如果你们中的任何一个发现自己遇到了这个问题......请注意框架中的某个地方有一个没有清除缓存或其他内容的错误。解决方案是我在设置SourceZoneSelect.ItemsSource之前添加这些行：
SourceZoneSelect.ClearValue(LongListSelector.ItemTemplateProperty);
SourceZoneSelect.ItemTemplate = null;
SourceZoneSelect.ItemTemplate = this.Resources["DataTemplateContentZone"] as DataTemplate;
因此，如果您想每次都运行转换器，则需要手动清除模板并再次应用