链接视图模型到视图
本文关键字:视图 模型 链接 | 更新日期: 2023-09-27 18:12:35
我不能得到我的xaml绑定我的视图模型。我在我的viewModel中有一个INotifyPropertyChanged类的ObservableCollection,它持有关于接收的数据。这是我的接收类:
namespace WP7SQLiteClient.Model
{
public class MainViewModelItem : INotifyPropertyChanged
{
string _title, _subTitle, _imageUriPath;
string title
{
get
{
return _title;
}
set
{
_title = value;
NotifyPropertyChanged("title");
}
}
string subTitle
{
get
{
return _subTitle;
}
set
{
_subTitle = value;
NotifyPropertyChanged("subTitle");
}
}
string imageUriPath
{
get
{
return _imageUriPath;
}
set
{
_imageUriPath = value;
NotifyPropertyChanged("imageUriPath");
}
}
public MainViewModelItem(string title, string subtitle, string imageuripath)
{
this.title = title;
this.subTitle = subtitle;
this.imageUriPath = imageuripath;
}
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
}
}
和我的ViewModel,其中包含接收列表:
namespace WP7SQLiteClient.ViewModel
{
public class PanoramaViewModel : INotifyPropertyChanged
{
public ObservableCollection<MainViewModelItem> _recepiesList;
public ObservableCollection<MainViewModelItem> recepiesList
{
get
{
return _recepiesList;
}
set
{
_recepiesList = value;
NotifyPropertyChanged("recepiesList");
}
}
public PanoramaViewModel()
{
this.recepiesList = new ObservableCollection<MainViewModelItem>();
}
public bool IsDataLoaded
{
get;
private set;
}
public void LoadData()
{
this.recepiesList.Add(new MainViewModelItem("Classics", "", ""));
this.recepiesList.Add(new MainViewModelItem("Perfect Pasta", "", ""));
this.recepiesList.Add(new MainViewModelItem("Favorites", "", ""));
this.recepiesList.Add(new MainViewModelItem("Snacks & Antipasti", "", ""));
this.recepiesList.Add(new MainViewModelItem("Desserts", "", ""));
this.recepiesList.Add(new MainViewModelItem("3 minutes recipes", "", ""));
this.IsDataLoaded = true;
}
private string _sampleProperty = "Sample Runtime Property Value";
/// <summary>
/// Sample ViewModel property; this property is used in the view to display its value using a Binding
/// </summary>
/// <returns></returns>
public string SampleProperty
{
get
{
return _sampleProperty;
}
set
{
if (value != _sampleProperty)
{
_sampleProperty = value;
NotifyPropertyChanged("SampleProperty");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
}
}
在我的主页。xaml(它在项目的根,viewModel是在viewModel文件夹和模型是在模型文件夹)我有我的列表框声明如下:
<ListBox x:Name="recepiesList" ItemTemplate="{StaticResource ListViewModelTemplate}" >
</ListBox>
模板位于App.xaml中,并且肯定是正确的。它使用{Binding title}
在MainPage.cs我尝试链接视图模型与页面使用:
public static PanoramaViewModel viewModel = null;
public static PanoramaViewModel ViewModel
{
get
{
// Delay creation of the view model until necessary
if (viewModel == null)
viewModel = new PanoramaViewModel();
return viewModel;
}
}
public MainPage()
{
InitializeComponent();
ViewModel.LoadData();
DataContext = ViewModel;
}
但是它不起作用,调试器也不会抛出错误。我怎样才能正确地链接视图模型与xaml ?
UPDATE我的模板是这样的:
<DataTemplate x:Key="ListViewModelTemplate"> <!-- for recent recepies-->
<Grid Width="400" Height="80" VerticalAlignment="Center">
<StackPanel Orientation="Vertical">
<Border CornerRadius="0" x:Name="brdTesat" BorderBrush="Black" BorderThickness="1" Width="80" Height="80">
<Border.Background>
<ImageBrush x:Name="backgroundImaageBrush" Stretch="Fill">
<ImageBrush.ImageSource>
<BitmapImage x:Name="bmapBackground" UriSource="{Binding imageUriPath}" >
</BitmapImage>
</ImageBrush.ImageSource>
</ImageBrush>
</Border.Background>
</Border>
<StackPanel>
<TextBlock TextAlignment="Left" Margin="7,4,4,4" Text="{Binding title}" TextWrapping="Wrap"></TextBlock>
<TextBlock TextAlignment="Left" Margin="7,4,4,4" Text="DA" TextWrapping="Wrap"></TextBlock>
</StackPanel>
</StackPanel>
</Grid>
</DataTemplate>
更新2
我把列表框代码改成:
<ListBox x:Name="recepiesList" ItemsSource="{Binding recepiesList}" > </ListBox>
没有模板,我得到了[project_name].Model.MainViewModelItem
的列表,所以我认为模板有问题。我做错了什么?
您需要将ListBox绑定到数据。所以,这应该对你有用。
<ListBox x:Name="recepiesList" ItemsSource="{Binding recepiesList}" ItemTemplate="{StaticResource ListViewModelTemplate}" />
我们在项目中使用MEF,并将视图模型与view . example .cs中的以下代码链接起来:
[Import]
public ConnectionStringSetupViewModel ViewModel
{
get { return DataContext as ConnectionStringSetupViewModel; }
set { DataContext = value; }
}
这允许在创建目录时满足导入。如果您不使用MEF,您可以使用上面相同的代码而不需要导入,但是当您创建视图时,您必须为它分配一个视图模型类的新实例。