Question

在C# WPF我有一个窗口，使用this.WorkingFrame.Navigate(Page1);来托管页面现在第1页我有一个listview。在第1页上，您可以双击listview中的项目以打开新窗口（第2页）来编辑项目。项目编辑后，会保存到datacontext。现在我遇到的问题是，一旦Page2关闭，listview就不会更新。基本上我必须离开页面并返回到它以显示更改。有没有办法从Page2刷新Page1以显示所做的更改？这是我的代码

public partial class Page1 : Page
{
    public Page1()
    {            
        InitializeComponent();
    }
    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        //initiates the method to load data into the list view
        LoadLV();
    }
    //Loads data into the list view object
    public void LoadLV()
    {

        auroraDataEntities = new AuroraDataEntities();
        Data data = new Data();
        ObjectQuery<Inventory> inventories = auroraDataEntities.Inventories;
        //Returns only objects with a quantity greater than 0, so it won't show anything you are out of
        var fillList = from q in inventories
                       where q.Qty > 0
                       select q;
        ingListLV.ItemsSource = fillList.ToList();

     }
    //Method to open what I want to be the child window basically a popup Dialog box
    private void Open_Page2(object sender, RoutedEventArgs e)
    {
        Page2 openPage2 = new Page2();
        openPage2.Show();

    }
}

    //This is the code for Page 2
public partial class Page2 : Window
{    


     public Page2()
    {            
        InitializeComponent();
        //ADDED a reference to Page1 in the constructor
        Page1 page1;
    }

    //Method when i click the close button on the page
    private void Close_Button(object sender, RoutedEventArgs e)
    {
    //In here is the code that I want to use to refresh the listview on page 1
            //ADDED the call to the public method LoadLV on page 1
            page1.LoadLV()              
    }
}

Answer 1

问题更为普遍 - 视图可能是任意复杂的，在某处修改的数据应该在其他地方失效/刷新。假设您不仅在父子关系中有两个窗口，而且还有一个复杂的嵌套视图，带有选项卡或动态浮动窗口。显然，这不仅仅是“刷新孩子的父母”。

那么可能的方法是什么？答案是：消息， publish-subsribe 模式。你需要一个 Event Aggregator ，例如你在Prism4中有一个。聚合器允许您的视图订阅消息并发布消息。

您的案例中的消息传递架构很简单。你需要一个事件，比如

public class BusinessEntityUpdatedEvent : CompositePresentationEvent
{
   public object Entity { get; set; }

   //or

   // if your entities share a common base class
   public EntityBase Entity { get; set; }   

   //or

   public justAnything ofAnyType { get; set; }
   public orEvenMore ofAnotherType { get; set; }
}

然后您的父视图订阅该事件，您的子视图发布事件，将更新的实体传递给事件参数。

一旦你了解了应用程序不同领域之间的消息传递，你的代码就会变得更少耦合，你就会停下来思考“这两个类之间是否有联系？也许是亲子关系？”但是你开始考虑“从那里到那里应该传递什么信息？”。

修改短期解决方案是：

public class Page1
{ 
   private void OpenPage2()
   {
      Page2 p = new Page2( this );
      p.Show();
   }

   public void LoadLv() ...
}

public class Page2
{
   private Page1 page1;
   public Page2( Page1 page1 )
   {
      this.page1 = page1;
   }

   public void CloseButton()
   {
      this.page1.LoadLV();
   }
}

Answer 2

MainWindow mainWindow = new MainWindow();

mainWindow.Closed += (s, eventarg) =>
{
    // Your method to update parent window
};

mainWindow.Show();

从子窗口刷新WPF页面

2 个答案: