如何限制wp8.1中的ListView项的内容-分页概念

Question

Iam working on WP8.1 Project I want to Display contents in ListBox. By default the listbox will show 5 Items, when the user scrolls to 7th item it should load next 10 items the loop should continue till all the data are displayed(Example: Same like how the scroll box size in Excel Sheet gets minimized when we scroll down)

Answer 1

for that you require two important things.

1) limit the items in the List (or any Collection ) that you're going to assign as the itemssource to the ListBox .

2) you have to detect the scroll reaching at the end of scroll viewer of listbox.

Now, eg. your XAML is this:

    <ListBox x:Name="lbx">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding}" />
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

and here is rest of code behind part.

    // two lists are for assigning ItemsSource and
    // other is for all items to represent.

    List<string> lstInt = new List<string>();
    List<string> lstIntFull = new List<string>();
    void BlankPage3_Loaded(object sender, RoutedEventArgs e)
    {
        // below code will get ScrollViewer from ListBox and define the event handler to it's ViewChanged event.

        sv = VisualTreeHelper.GetChild((VisualTreeHelper.GetChild(lbx, 0) as Border), 0) as ScrollViewer;
        sv.ViewChanged += sv_ViewChanged;

        for (int i = 0; i < 100; i++)
        {
            lstIntFull.Add(i.ToString());
        }

        for (int i = 0; i <= 10; i++)
        {
            lstInt.Add(lstIntFull[i]);
        }

        lbx.ItemsSource = lstInt;
    }

    // event handler of ViewChanged event that we declared on PageLoad
    void sv_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
    {
        var verticalOffset = sv.VerticalOffset;
        var maxVerticalOffset = sv.ScrollableHeight; //sv.ExtentHeight - sv.ViewportHeight;

        if (maxVerticalOffset < 0 ||
            verticalOffset == maxVerticalOffset)
        {

            // Scrolled to bottom
            // So, write the code here to load next set of data

            var itemCount = (lbx.ItemsSource as List<string>).Count;
            for (int i = itemCount; i <= itemCount + 10; i++)
            {
                if (i < 100)
                {
                    lstInt.Add(lstIntFull[i]);
                }
            }

            // await Task.Delay(2000);

            // lbx.ItemsSource = null;
            lbx.ItemsSource = lstInt;
        }
        else
        {
            // Not scrolled to bottom

        }
    }

Now compare your example with this one. and follow the steps to your answer.

This Concept is called Pagination .

Check this link to find out how to detect the ScrollViewer reaches at the End of Scrollable height.