我有课
public class Clip
{
public string ID { get; set; }
public string Name { get; set; }
public int? Duration { get; set; }
}
ObservableCollection
public ObservableCollection<Clip> _clipsFound;
public ObservableCollection<Clip> collection
{
get { return _clipsFound; }
set
{
_clipsFound = value;
OnPropertyChanged();
}
}
我执行时会调用 OnPropertyChanged()
_clipsFound = collection
我希望从集合到ListBox的绑定数据有三列:ID,Name,Duration
初始化
ID = id;
collection = new ObservableCollection<Clip>();
_clipsFound = collection;
_clipsFound.Clear();
ICollection<Clip> ClipF = await Service.GetClips(ID);
ICollection<Clip> Clipcol = ClipF;
collection = new ObservableCollection<Clip>(Clipcol);
我尝试这样做,但它不起作用
<ListBox Grid.Row="2" ItemsSource="{Binding collection}" BorderBrush="Transparent" >
<ListBox.ItemTemplate>
<DataTemplate DataType="ui:Clip">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0"
Text="{Binding Title}"
VerticalAlignment="Center"
HorizontalAlignment="Left"
TextTrimming="CharacterEllipsis"
Foreground="#FF4F4F4F"
FontSize="12"
Margin="55 0 0 0"/>
<TextBlock Grid.Column="1"
Margin="0 0 45 0"
Text="{Binding Duration}"
VerticalAlignment="Center"
HorizontalAlignment="Right"
FontSize="11"
Foreground="#FF4F4F4F"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
我做错了什么?
答案 0 :(得分:1)
如果不设置DataContext
,则无法从viewmodel发送数据进行查看。 DataContext
就像ViewModel
和View
之间的渠道或桥梁。
此代码设置DataContext
:
<Window.DataContext>
<vm:MainWindowViewModel />
</Window.DataContext>
让我们看看工作示例:
您的ViewModel:
public class MainWindowViewModel
{
publicMainWindowViewModel
{
LoadData();
}
private void LoadData()
{
_clipsFound=new ObservableCollection<Clip>();
for(int startIndex=0; startIndex<10; startIndex++)
{
collection.Add(new Clip(){ID=startIndex, Name="Bob", Duration=startIndex++});
}
}
public ObservableCollection<Clip> _clipsFound;
public ObservableCollection<Clip> collection
{
get
{
return _clipsFound;
}
set
{
_clipsFound = value;
}
}
}
您的XAML:
<Window x:Class="DataGridSelectedItemsWpfApplication.MainWindow"
...The code omitted for the brevity...
xmlns:vm="clr-namespace:DataGridSelectedItemsWpfApplication.ViewModel"
Title="MainWindow" WindowStartupLocation="CenterScreen" Height="550" Width="525">
<Window.DataContext>
<vm:MainWindowViewModel />
</Window.DataContext>
<ListBox Grid.Row="2" ItemsSource="{Binding collection}" BorderBrush="Transparent" >
<ListBox.ItemTemplate>
<DataTemplate DataType="ui:Clip">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding ID}" VerticalAlignment="Center" HorizontalAlignment="Center" FontSize="11" Margin="2" Foreground="#FF4F4F4F"/>
<TextBlock Grid.Column="1" Margin="2" Text="{Binding Name}" VerticalAlignment="Center" HorizontalAlignment="Center" TextTrimming="CharacterEllipsis" Foreground="#FF4F4F4F" FontSize="12"/>
<TextBlock Grid.Column="2" Margin="2" Text="{Binding Duration}" VerticalAlignment="Center" HorizontalAlignment="Center" FontSize="11" Foreground="#FF4F4F4F"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Window>