如何从一组物品中选择特定物品？

Question

我使用的Windows Phone的DataBoundApp模板，在模板中的selectedIndex值从传递的MainPage到DetailsPage定义数据上下文...这样的：

// When page is navigated to set data context to selected item in list 
    protected override void OnNavigatedTo(NavigationEventArgs e) 
    { 
     string selectedIndex = ""; 
     if (NavigationContext.QueryString.TryGetValue("selectedItem", out selectedIndex)) 
     { 
      int index = int.Parse(selectedIndex); 
      DataContext = App.ViewModel.Items[index]; 
     } 
    } 

这是设置的唯一途径数据上下文或我可以选择一个具有特定值的项目，例如，我想将数据上下文设置为具有LineOne =“runtime 7”值的项目...

我该如何设置？

编辑：这些都是视图模型项目

public void LoadData() 
    { 
     // Sample data; replace with real data 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime one", LineTwo = "Maecenas praesent accumsan bibendum", LineThree = "Facilisi faucibus habitant inceptos interdum lobortis nascetur pharetra placerat pulvinar sagittis senectus sociosqu" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime two", LineTwo = "Dictumst eleifend facilisi faucibus", LineThree = "Suscipit torquent ultrices vehicula volutpat maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime three", LineTwo = "Habitant inceptos interdum lobortis", LineThree = "Habitant inceptos interdum lobortis nascetur pharetra placerat pulvinar sagittis senectus sociosqu suscipit torquent" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime four", LineTwo = "Nascetur pharetra placerat pulvinar", LineThree = "Ultrices vehicula volutpat maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime five", LineTwo = "Maecenas praesent accumsan bibendum", LineThree = "Maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos interdum lobortis nascetur" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime six", LineTwo = "Dictumst eleifend facilisi faucibus", LineThree = "Pharetra placerat pulvinar sagittis senectus sociosqu suscipit torquent ultrices vehicula volutpat maecenas praesent" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime seven", LineTwo = "Habitant inceptos interdum lobortis", LineThree = "Accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos interdum lobortis nascetur pharetra placerat" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime eight", LineTwo = "Nascetur pharetra placerat pulvinar", LineThree = "Pulvinar sagittis senectus sociosqu suscipit torquent ultrices vehicula volutpat maecenas praesent accumsan bibendum" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime nine", LineTwo = "Maecenas praesent accumsan bibendum", LineThree = "Facilisi faucibus habitant inceptos interdum lobortis nascetur pharetra placerat pulvinar sagittis senectus sociosqu" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime ten", LineTwo = "Dictumst eleifend facilisi faucibus", LineThree = "Suscipit torquent ultrices vehicula volutpat maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime eleven", LineTwo = "Habitant inceptos interdum lobortis", LineThree = "Habitant inceptos interdum lobortis nascetur pharetra placerat pulvinar sagittis senectus sociosqu suscipit torquent" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime twelve", LineTwo = "Nascetur pharetra placerat pulvinar", LineThree = "Ultrices vehicula volutpat maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime thirteen", LineTwo = "Maecenas praesent accumsan bibendum", LineThree = "Maecenas praesent accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos interdum lobortis nascetur" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime fourteen", LineTwo = "Dictumst eleifend facilisi faucibus", LineThree = "Pharetra placerat pulvinar sagittis senectus sociosqu suscipit torquent ultrices vehicula volutpat maecenas praesent" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime fifteen", LineTwo = "Habitant inceptos interdum lobortis", LineThree = "Accumsan bibendum dictumst eleifend facilisi faucibus habitant inceptos interdum lobortis nascetur pharetra placerat" }); 
     this.Items.Add(new ItemViewModel() { LineOne = "runtime sixteen", LineTwo = "Nascetur pharetra placerat pulvinar", LineThree = "Pulvinar sagittis senectus sociosqu suscipit torquent ultrices vehicula volutpat maecenas praesent accumsan bibendum" }); 

     this.IsDataLoaded = true; 
    } 

我不希望通过该项目的索引号来设置数据上下文，而是由一个特定的项目值

Answer 1

只要你能给重视你正在寻找的价值，下面的工作。

string value = "runtime seven"; 

DataContext = App.ViewModel.Items.FirstOrDefault(item => item.LineOne == value);