用WPF C中的数据绑定更改组合框的选定索引＃

Question

我试图在c＃中将Winforms转换为WPF。我正在努力与WVVM和data binding。我承认我没有全面掌握所有方法的一致性，但我认为我只需要更多练习。

我使用this article on codeproject来帮助我理解如何将本地通讯簿应用程序从WinForms转换为WPF。

虽然我可以得到数据绑定工作正常与int和字符串我挣扎着一个组合框。数据存储在一个xml文件中，并存储为联系人类中的字符串和int。从列表框中选择位置时，ComboBox应自动更新。我有这一切工作的属性，允许用户自定义信息。这个特定的设置需要预设值的下拉菜单。

如何转换字符串并通过数据绑定将SelectedIndex []属性传递给组合框？

我省略了一些额外的工作代码用于文本框的字符串填充一些清理它。

XAML

<Window 
    <Window.DataContext> 
     <viewmodels:mainviewModel x:Name="viewModel1"/> 
    </Window.DataContext> 
    <Grid Background="#FF8B8686"> 
     <ListBox x:Name="listBox" HorizontalAlignment="Left" Height="174" Margin="44,77,0,0" VerticalAlignment="Top" Width="164" ItemsSource="{Binding Contacts}" DisplayMemberPath="Name" SelectedItem="{Binding SelectedContact}" SelectionChanged="listBox_SelectionChanged" /> 
     <TextBox x:Name="textBoxName" HorizontalAlignment="Left" Height="23" Margin="244,77,0,0" TextWrapping="Wrap" Text="{Binding SelectedContact.Name}" VerticalAlignment="Top" Width="120"/> 
     <TextBox x:Name="textBoxAddress" HorizontalAlignment="Left" Height="23" Margin="244,120,0,0" TextWrapping="Wrap" Text="{Binding SelectedContact.Address}" VerticalAlignment="Top" Width="120"/> 
     <TextBox x:Name="textBoxBandwidth" HorizontalAlignment="Left" Height="23" Margin="244,198,0,0" TextWrapping="Wrap" Text="{Binding SelectedContact.Bandwidth}" VerticalAlignment="Top" Width="120" DataContext="{Binding Mode=OneWay}"/> 
     <Button x:Name="button1" Content="Write Data" HorizontalAlignment="Left" Margin="194,271,0,0" VerticalAlignment="Top" Width="75" Click="button1_Click"/> 
     <ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="267,229,0,0" VerticalAlignment="Top" Width="120" SelectedItem="{Binding SelectedContact.Combo}"> 
      <ComboBoxItem Content="1" /> 
      <ComboBoxItem Content="2" /> 
      <ComboBoxItem Content="3" /> 
      <ComboBoxItem Content="4" /> 
      </ComboBox> 
    </Grid> 
</Window> 

Contact.cs

public class Contact : ViewModelEntity 
{ 
    public Contact() 
    { 
    } 

    protected int combo; 
    public int Combo 
    { 
     get { return combo; } 
     set 
     { 
      if (combo != value) 
      { 
       switch (value) 
       { 
        case 1: 
         combo = ComboBox.SelectedIndex[0]; 
         break; 
        case 2: 
         combo = ComboBox.SelectedIndex[1]; 
         break; 
        case 3: 
         combo = ComboBox.SelectedIndex[2]; 
         break; 
        case 4: 
         combo = ComboBox.SelectedIndex[3]; 
         break; 
        default: 
         combo = ComboBox.SelectedIndex[0]; 
         break; 
       } 
       // combo = value; 
       NotifyPropertyChanged("Combo"); 
      } 
     } 
    } 

mainviewModel.cs

using System.Collections.ObjectModel; 

namespace WpfApplication1.viewmodels 
{ 
    public class mainviewModel:ViewModelEntity 
    { 

     public mainviewModel() 
     { } 
     protected Contact selectedContact = null; 

     protected ObservableCollection<Contact> contacts = new ObservableCollection<Contact>(); 

     public ObservableCollection<Contact> Contacts 
     { 
      get { return contacts; } 
      set { contacts = value; } 
     } 


     public Contact SelectedContact 
     { 
      get { return selectedContact; } 
      set { 
       if (selectedContact != value) 
       { 
        selectedContact = value; 
        NotifyPropertyChanged("SelectedContact"); 
       } 


      } 
     } 
    } 
} 

Answer 1

你为什么不直接将其绑定到SelectedIndex直接？

<ComboBox x:Name="comboBox" 
       Width="120" 
       Margin="267,229,0,0" 
       HorizontalAlignment="Left" 
       VerticalAlignment="Top" 
       SelectedIndex="{Binding SelectedContact.Combo}"> 
     <ComboBoxItem Content="1" /> 
     <ComboBoxItem Content="2" /> 
     <ComboBoxItem Content="3" /> 
     <ComboBoxItem Content="4" /> 
    </ComboBox> 

在后面的代码：

protected int combo; 
public int Combo 
{ 
    get { return combo; } 
    set 
    { 
     combo = value; 
     NotifyPropertyChanged("Combo");   
    } 
}