樣式在listview中的第n項？

Question

我有一個外部'當前'屬性（int），它表示集合的當前索引。我有一個顯示這個集合的列表視圖。我希望能夠根據「當前」值設置集合的「第n個」項目，即當前值爲3時，突出顯示集合中的第4個項目（索引= 3）等。我該怎麼做？

另一種方法是在項目文本等於另一個外部屬性時進行綁定。

Answer 1

要自定義ListView的樣式，可以創建一個DataTrigger，該DataTrigger綁定到View的DataContext的屬性以更改當前樣式。在這個例子中，代碼改變了背景。

<ListView.ItemContainerStyle> 
    <Style TargetType="ListViewItem"> 
    <Setter Property="Background" Value="Aqua"/> 
     <Style.Triggers> 
     <DataTrigger Binding="{Binding Path=DataContext.StyleType, RelativeSource={RelativeSource Self}}" Value="1"> 
      <Setter Property="Background" Value="Chartreuse"/> 
     </DataTrigger> 
     </Style.Triggers> 
    </Style> 
</ListView.ItemContainerStyle> 

我添加的大多數代碼，你在這兒可以得到儘可能完整的畫面儘可能發生了什麼，但我跳過了共同MVVM基類。

工作原理：

1. ListView控件的ItemsSource綁定到客戶
2. ListView控件的SelectedItem綁定到客戶
3. ListView.ItemContainerStyle具有結合到DataContext.StyleType
4. DataContext的一個DataTrigger是一個列表客戶對象與用戶定義的StyleType屬性在代碼隱藏中初始化
5. Button Command清除StyleType的值
6. 點擊一行改變下一行
7. 客戶實現INotifyPropertyChanged的風格，即火災時，StyleType改變
8. DataTrigger改變背景每個ListViewItem的

這裏是XAML，看DataTrigger：

<Window x:Class="ListViewScrollPosition.Views.ScrollBarwindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="Style on Model" Height="300" Width="300"> 
    <Grid> 
     <Grid.RowDefinitions> 
      <RowDefinition/> 
      <RowDefinition Height="Auto"/> 
     </Grid.RowDefinitions> 
     <ListView 
      Grid.Row="0" 
      SelectedItem="{Binding Customer}" 
      ItemsSource="{Binding Customers}" x:Name="myListView"> 
      <ListView.ItemContainerStyle> 
       <Style TargetType="ListViewItem"> 
        <Setter Property="HorizontalContentAlignment" Value="Stretch" /> 
        <Setter Property="Background" Value="Aqua"/> 
        <Style.Triggers> 
         <DataTrigger Binding="{Binding Path=DataContext.StyleType, RelativeSource={RelativeSource Self}}" Value="1"> 
          <Setter Property="Background" Value="Pink"/> 
         </DataTrigger> 
        </Style.Triggers> 
       </Style> 
      </ListView.ItemContainerStyle> 
      <ListView.View> 
       <GridView> 
        <GridViewColumn Header="First Name" 
            DisplayMemberBinding="{Binding FirstName}" /> 
        <GridViewColumn Header="Last Name" 
            DisplayMemberBinding="{Binding LastName}" /> 
        <GridViewColumn Header="Style Type" 
            DisplayMemberBinding="{Binding StyleType}" /> 
       </GridView> 
      </ListView.View> 
     </ListView> 
     <Button Grid.Row="1" Content="Change Style" Command="{Binding Path=AlterStyle}"/> 
    </Grid> 
</Window> 

這裏是視圖模型視圖用於獲取客戶和改變StyleType的價值：

using System.Collections.Generic; 
using System.Windows.Input; 
using ListViewScrollPosition.Commands; 
using ListViewScrollPosition.Models; 

namespace ListViewScrollPosition.ViewModels 
{ 
public class MainViewModel : ViewModelBase 
{ 
    private DelegateCommand _alterStyleCommand; 

    public MainViewModel() 
    { 
    } 

    public ICommand AlterStyle 
    { 
    get 
    { 
     if (_alterStyleCommand == null) 
     { 
      _alterStyleCommand = new DelegateCommand(AlterStyleCommand); 
     } 
     return _alterStyleCommand; 
    } 
    } 

    private void AlterStyleCommand() 
    { 
    foreach (var customer in Customers) 
    { 
     customer.StyleType = 0; 
    } 
    } 

    private void ApplyStyleToNextRow(Customer currentCustomer) 
    { 
    bool setNext = false; 
    foreach (var customer in Customers) 
    { 
     if (setNext) 
     { 
     customer.StyleType = 1; 
     setNext = false; 
     } 
     else 
     { 
     customer.StyleType = 0; 
     } 

     if (currentCustomer == customer) 
     { 
     setNext = true; 
     } 
    } 
    } 

    private List<Customer> _customers = Customer.GetSampleCustomerList(); 
    public List<Customer> Customers 
    { 
    get 
    { 
     return _customers; 
    } 
    } 

    private Customer _customer = null; 
    public Customer Customer 
    { 
    get 
    { 
     return _customer; 
    } 
    set 
    { 
     _customer = value; 
     ApplyStyleToNextRow(_customer); 
     OnPropertyChanged("Customer"); 
    } 
    } 
} 
} 

這裏是模型，ViewModelBase實現INotifyPropertyChanged，當改變了更新每個ListViewItem的StyleType火災OnPropertyChanged：

using System; 
using System.Collections.Generic; 

namespace ListViewScrollPosition.Models 
{ 
    public class Customer : ViewModels.ViewModelBase 
    { 
    public String FirstName { get; set; } 
    public String LastName { get; set; } 

    private int _style; 
    public int StyleType 
    { 
     get { return _style;} 
     set 
     { 
     _style = value; 
     OnPropertyChanged("StyleType"); 
     } 
    } 

    public Customer(String firstName, String lastName, int styleType) 
    { 
     this.FirstName = firstName; 
     this.LastName = lastName; 
     this.StyleType = styleType; 
    } 

    public static List<Customer> GetSampleCustomerList() 
    { 
    return new List<Customer>(new Customer[4] { 
      new Customer("A.", "Zero", 0), 
      new Customer("B.", "One", 1), 
      new Customer("C.", "Two", 2), 
      new Customer("D.", "Three", 1) 
     }); 
    } 
    } 
} 

這裏是代碼隱藏在哪裏設置在DataContext：

using System.Windows; 
namespace ListViewScrollPosition.Views 
{ 
    public partial class ScrollBarwindow : Window 
    { 
    public ScrollBarwindow() 
    { 
     InitializeComponent(); 
     DataContext = new ViewModels.MainViewModel(); 
    } 
    } 
}