用WPF C中的數據綁定更改組合框的選定索引＃

Question

我試圖在c＃中將Winforms轉換爲WPF。我正在努力與WVVM和data binding。我承認我沒有全面掌握所有方法的一致性，但我認爲我只需要更多練習。

我使用this article on codeproject來幫助我理解如何將本地通訊簿應用程序從WinForms轉換爲WPF。

雖然我可以得到數據綁定工作正常與int和字符串我掙扎着一個組合框。數據存儲在一個xml文件中，並存儲爲聯繫人類中的字符串和int。從列表框中選擇位置時，ComboBox應自動更新。我有這一切工作的屬性，允許用戶自定義信息。這個特定的設置需要預設值的下拉菜單。

如何轉換字符串並通過數據綁定將SelectedIndex []屬性傳遞給組合框？

我省略了一些額外的工作代碼用於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

你爲什麼不直接將其綁定到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> 

在後面的代碼：

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