Windows Phone 7:如何通知 ListBox 中的数据更新? [英] Windows Phone 7: How to notify data is updated in ListBox?

问题描述

我有上面的场景:如果用户点击 ListBox，它将有子项(同样是 ListBox)或详细信息视图.

I have above scenario: If user click on ListBox, it will either have sub items (again ListBox) or detail view.

所以我目前所做的是:每当用户单击任何项​​目时，如果单击的项目有更多子项目，则进行网络调用并填充相同的列表框.

So what i did currently is: Whenever user clicks any item, made a web call and filled up the same ListBox if clicked item is having further sub items.

现在，问题出现了:

1. 假设我在第 4 个屏幕(详细视图)，
2. 移动到第三个和第二个屏幕，数据保持为堆栈(它工作正常，是的，我在 ObservableCollection<ObservableCollection<MyObjects>> 中维护数据，所以在向后移动时，我正在获取数据从那里)
3. 现在，如果我单击屏幕 2 中的任何项目，它将打开屏幕 3 列表框数据的详细视图.

1. Suppose i am in 4th screen (detail view),
2. Moved to the 3rd and 2nd screen with data maintained as stack (Its working fine, yes i am maintaining data in ObservableCollection<ObservableCollection<MyObjects>> so while moving back, i am fetching data from there)
3. Now, if i click any item in screen 2, it will open detail view for the screen 3 ListBox data.

意味着 ListBox 没有收到我们在 OnBackKeyPress()

Means that ListBox is not getting notified that we have filled data inside OnBackKeyPress()

仅供参考，我正在同一页面中填充 ListBox 和 WebBrowser.，所以我的问题是，一旦我从我维护的堆栈中填充了数据，我该如何通知 ListBox?

FYI, i am filling up ListBox and WebBrowser in the same page., so my problem is that how do i notify ListBox once i filled up data from stack which i have maintained?

是的，我也实现了 INotifyPropertyChanged 但不知道为什么它不起作用.

Yes i have also implemented INotifyPropertyChanged but don't know why its not working.

请检查我的代码:

1. ListBox 和 WebView 屏幕:http://pastebin.com/K1G27Yji
2. 具有 INotifyPropertyChanged 实现的 RootPageItem 类文件:http://pastebin.com/E0uqLtVG

1. ListBox and WebView screen: http://pastebin.com/K1G27Yji
2. RootPageItem class file with the implementation of INotifyPropertyChanged: http://pastebin.com/E0uqLtVG

抱歉以上述方式粘贴代码，我这样做是因为问题很长.

sorry for pasting code in above way, i did as question is being long.

如何通知 ListBox 数据已从 OnBackKeyPress 更改?

How do i notify ListBox that data is changed from OnBackKeyPress?

推荐答案

糟糕，我犯了一个愚蠢的错误.

Oops it was a silly mistake i made.

我忘记在 OnBackKeyPress() 中设置 items[] 数组，但是在单击 item 时正在访问，因此它具有我们向前移动的最后一步的 items[] 数据，它正在执行相同的数据.

I forgot to set items[] array inside OnBackKeyPress() but was accessing while clicking item, hence its having items[] data of last step we moved in forward direction, it was executing the same data.

现在，我只包含了一行，它解决了我的问题.

Now, i have just included a single line and it has solved my problem.

 items = listRootPageItems.ToArray();  // resolution point

所以 onBackKeyPress() 的最终代码是:

So final code of onBackKeyPress() is:

/**
 * While moving back, taking data from stack and displayed inside the same ListBox
 * */
 protected override void OnBackKeyPress(CancelEventArgs e)
 {
     listBox1.Visibility = Visibility.Visible;
     webBrowser1.Visibility = Visibility.Collapsed;
     listBox1.SelectedIndex = -1;

     if (dataStack.Count != 0)
     {
          listBox1.ItemsSource = null;
          listRootPageItems = dataStack[dataStack.Count-1];
          listBox1.ItemsSource = listRootPageItems;

               items = listRootPageItems.ToArray();  // resolution point
          dataStack.Remove(listRootPageItems);

          e.Cancel = true;
      }
 }

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