[英]MVVM based Item binding to two Windows Phone controls
我在单个页面上有两个控件:
1. RadSlider
2.列表框
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="100"></RowDefinition>
</Grid.RowDefinitions>
<telerik:RadSlideView Name="imgSlidView" >
<telerik:RadSlideView.ItemTemplate>
<DataTemplate>
<Image Source="{Binding Src}"></Image>
</DataTemplate>
</telerik:RadSlideView.ItemTemplate>
<telerik:RadSlideView.ItemPreviewTemplate>
<DataTemplate>
<telerik:RadBusyIndicator></telerik:RadBusyIndicator>
</DataTemplate>
</telerik:RadSlideView.ItemPreviewTemplate>
</telerik:RadSlideView>
<ListBox Grid.Row="1" Name="lstImage">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"></StackPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Image Height="100" Margin="0,0,5,0" Source="{Binding Src}"></Image>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
我想将两个控件绑定到单个Item Source,这样,如果一个选项的选择更改了,其他选项的选择也应该更改。
我对基于MVVM的解决方案感兴趣。 我的代码:
class CategoryViewModel : ViewModelBase
{
public ObservableCollection<ImageSource> ImageCollection { get; set; }
private ImageSource _CurrentImage;
public ImageSource CurrentImage
{
get { return _CurrentImage; }
set
{
_CurrentImage = value;
RaisePropertyChanged("CurrentImage");
}
}
}
除此之外,我还有一段代码返回IEnumerable,我希望它可以作为Item Source。
public static async Task<IEnumerable<Object>> GetCategoryNames()
{
if (Categories == null)
{
JDir dir = Newtonsoft.Json.JsonConvert.DeserializeObject<JDir>(await LoadFromJson());
Categories = ConvertJDirToCategory(dir);
return Categories.Select(p => new { Name = p.Name, Src = "Images/" + p.Name + ".jpg" });
}
else
{
return Categories.Select(p => new { Name = p.Name, Src = "Images/" + p.Name + ".jpg" });
}
}
我做对了吗? 我应该如何进行?
提前致谢 !
编辑 -从评论:
private static async Task<string> LoadFromJson()
{
string theData = string.Empty;
StorageFile file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///data.json"));
using (StreamReader streamReader = new StreamReader(await file.OpenStreamForReadAsync()))
{
return await streamReader.ReadToEndAsync();
}
}
谢谢大家,我的问题现在已经解决:
XAML:
DataContext="{Binding Category, Source={StaticResource Locator}}"
两个控件:
<telerik:RadSlideView Name="imgSlidView" SelectedItem="{Binding SelectedItem,Mode=TwoWay}" ItemsSource="{Binding Images}">
<telerik:RadSlideView.ItemTemplate>
<DataTemplate>
<Image Source="{Binding}">
<telerik:RadContextMenu.ContextMenu>
<telerik:RadContextMenu IsZoomEnabled="False" OpenGesture="Tap">
<telerik:RadContextMenuItem Tap="RadContextMenuItem_Tap" Content="Share">
</telerik:RadContextMenuItem>
</telerik:RadContextMenu>
</telerik:RadContextMenu.ContextMenu>
</Image>
</DataTemplate>
</telerik:RadSlideView.ItemTemplate>
<telerik:RadSlideView.ItemPreviewTemplate>
<DataTemplate>
<telerik:RadBusyIndicator></telerik:RadBusyIndicator>
</DataTemplate>
</telerik:RadSlideView.ItemPreviewTemplate>
</telerik:RadSlideView>
<ListBox Grid.Row="1" ScrollViewer.HorizontalScrollBarVisibility="Auto" Name="lstImage" SelectedItem="{Binding SelectedItem,Mode=TwoWay}" ItemsSource="{Binding Images}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"></StackPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Image Height="100" Margin="0,0,5,0" Source="{Binding}">
</Image>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
查看模型:
public class CategoryViewModel : ViewModelBase
{
private string _CategoryName;
public string CategoryName
{
get { return _CategoryName; }
set
{
DispatcherHelper.CheckBeginInvokeOnUI(() => { Set<string>(ref _CategoryName, value); });
}
}
private Uri _SelectedItem;
public Uri SelectedItem
{
get { return _SelectedItem; }
set
{
DispatcherHelper.CheckBeginInvokeOnUI(() => { Set<Uri>(ref _SelectedItem, value); });
}
}
private ObservableCollection<Uri> _Images;
public ObservableCollection<Uri> Images
{
get { return _Images; }
set { Set<ObservableCollection<Uri>>(ref _Images, value); }
}
public CategoryViewModel()
{
CategoryName = string.Empty;
Images = new ObservableCollection<Uri>();
}
}
XAML.cs
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
string Category = string.Empty;
NavigationContext.QueryString.TryGetValue("category", out Category);
if (this.DataContext is CategoryViewModel)
{
var vm = (CategoryViewModel)this.DataContext;
vm.Images.Clear();
JSONHelper.LoadFromJson().ContinueWith(t =>
{
vm.CategoryName = Category;
var images = t.Result.Dirs.FirstOrDefault(p => p.DirName == Category).Files;
Dispatcher.BeginInvoke(() =>
{
foreach (var img in images)
{
vm.Images.Add(new Uri(string.Format("Data/{0}/{1}", Category, img), UriKind.Relative));
}
});
});
}
}
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