首先，为了使用 WPF 或其他基于 XAML 的技术，您必须了解这一点
UI is not Data. Data is Data. UI is UI.
这意味着您不应该在代码中操纵任何ComboBox 或任何其他 UI 元素，以便用数据填充它们，而是创建一个 ViewModel 并将这些对象绑定到它。
在此示例中，Window 本身用作ViewModel，因为它是一个简单的示例，但您应该考虑将所有应用程序逻辑移至单独的类：
<Window x:Class="MiscSamples.UIisNotData"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="UIisNotData" Height="300" Width="300">
<UniformGrid Rows="1" Columns="2">
<DockPanel>
<TextBlock Text="Owners:" DockPanel.Dock="Top" FontWeight="Bold" TextAlignment="Center" Margin="2"/>
<Button Content="Add" Width="80" DockPanel.Dock="Bottom" Margin="2" Click="AddOwner"/>
<ListBox ItemsSource="{Binding Owners}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<TextBlock Text="{Binding Name}" x:Name="block"/>
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" Visibility="Collapsed" x:Name="box"/>
</Grid>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType=ListBoxItem}}" Value="True">
<Setter TargetName="block" Property="Visibility" Value="Collapsed"/>
<Setter TargetName="box" Property="Visibility" Value="Visible"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DockPanel>
<DockPanel>
<TextBlock Text="Dogs:" DockPanel.Dock="Top" FontWeight="Bold" TextAlignment="Center" Margin="2"/>
<ListBox ItemsSource="{Binding Dogs}" HorizontalContentAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel>
<ComboBox ItemsSource="{Binding DataContext.Owners, RelativeSource={RelativeSource FindAncestor, AncestorType=Window}}"
SelectedItem="{Binding Owner}" DisplayMemberPath="Name"
DockPanel.Dock="Right" Width="100"/>
<TextBlock>
<Run Text="{Binding Name}"/>
<Run Text=", "/>
<Run Text="{Binding Kind}"/>
</TextBlock>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DockPanel>
</UniformGrid>
</Window>
后面的代码（此代码应放在 ViewModel 中）：
public partial class UIisNotData : Window
{
public ObservableCollection<Owner> Owners { get; set; }
public ObservableCollection<string> Kinds { get; set; }
public ObservableCollection<Dog> Dogs { get; set; }
public UIisNotData()
{
InitializeComponent();
Owners = new ObservableCollection<Owner>
{
new Owner() {Name = "Jack"},
new Owner() {Name = "Mike"},
new Owner() {Name = "Kirk"},
new Owner() {Name = "John"},
};
Kinds = new ObservableCollection<string>
{
"Affenpinscher",
"Afghan Hound",
"Airedale Terrier",
"Akita"
//.. All the rest of dog Breeds taken from http://www.petmd.com/dog/breeds?breed_list=az#.UVsQKpPcmQo
};
Dogs = new ObservableCollection<Dog>
{
new Dog() {Name = "Bobby", Kind = Kinds[0], Owner = Owners[0]},
new Dog() {Name = "Fido", Kind = Kinds[1], Owner = Owners[1]},
new Dog() {Name = "Toby", Kind = Kinds[2], Owner = Owners[2]}
};
DataContext = this;
}
private void AddOwner(object sender, RoutedEventArgs e)
{
Owners.Add(new Owner(){Name = "New Owner"});
}
}
数据模型：
public class Owner : PropertyChangedBase
{
private string _name;
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
}
public class Dog: PropertyChangedBase
{
private string _name;
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
private Owner _owner;
public Owner Owner
{
get { return _owner; }
set
{
_owner = value;
OnPropertyChanged("Owner");
}
}
private string _kind;
public string Kind
{
get { return _kind; }
set
{
_kind = value;
OnPropertyChanged("Kind");
}
}
}
PropertyChangedBase 类：
public class PropertyChangedBase:INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
结果：
关于此示例，您需要考虑 3 个重要方面：
- 我绝不会在代码中操纵 UI 元素。这在 WPF 中大部分时间是完全没有必要的。
- 数据模型中的类实现
INotifyPropertyChanged 以支持 WPF 中的 2 路绑定。
- 集合的类型为
ObservableCollection<T>，以便在从集合中添加/删除元素时支持自动通知（以便自动更新 ListBoxes 等）。
您可能会注意到的另一件事是，我的示例中的 XAML 元素没有特定的大小或 Margin 值。 Margin="338,10,0,0" 之类的东西通常是您从 Visual Studio 设计器那里得到的，表示布局结构不佳。我建议您查看 WPF 中的布局元素（DockPanel、StackPanel、Grid、UniformGrid、WrapPanel 等），然后自己开始编写 XAML，而不是使用设计器。这将允许更高级别的可扩展性，并且还将使您摆脱固定位置元素的细微差别。