下拉以刷新Windows Phone 8.1 Silverlight中的列表框

Question

我是Windows Phone開發的新手。 我想嘗試實施下拉菜單以刷新頁面。 我在scrollviewer下使用列表框，但在Windows Phone 8.1 Silverlight應用程序中實施時遇到問題。 這是我的代碼

MainPage.xaml中

<phone:PhoneApplicationPage
    x:Class="PullDownToScroll.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
    <Grid>


            <ScrollViewer Name="OuterScroll" Loaded="OuterScroll_Loaded" LayoutUpdated="OuterScroll_ViewChanged">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="60"/>
                    <RowDefinition/>
                </Grid.RowDefinitions>

                <Grid Background="GreenYellow">
                    <Image Source="Assets/down13.png" Height="40" Width="40" HorizontalAlignment="Left" Margin="20,0,0,0">
                        <Image.RenderTransform>
                            <RotateTransform x:Name="RefreshIndicatiorRotateTransform" CenterX="20" CenterY="20"/>
                        </Image.RenderTransform>
                    </Image>
                    <TextBlock Name="RefreshIndicatiorTextBlock" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="80,0,0,0" Width="200" Foreground="Black"/>
                </Grid>

                <ListBox Name="InnerListView" Grid.Row="1">

                </ListBox>
            </Grid>
        </ScrollViewer>

    </Grid>    
    </Grid>

</phone:PhoneApplicationPage>

MainPage.xaml.cs中

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;
using PullDownToScroll.Resources;
using System.Windows.Media;

namespace PullDownToScroll
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
            this.InitializeComponent();
            InnerListView.Height = ApplicationView.GetForCurrentView().VisibleBounds.Height;
            GenerateRandomListViewItem();
            this.NavigationCacheMode = NavigationCacheMode.Required;

            // Sample code to localize the ApplicationBar
            //BuildLocalizedApplicationBar();
        }

        public void GenerateRandomListViewItem()
        {
            InnerListView.Items.Clear();
            Random rand = new Random();
            for (int i = 0; i < 20; i++)
            {
                ListBox item = new ListBox();
                item.Background = new SolidColorBrush(Color.FromArgb(255, (byte)rand.Next(0, 255), (byte)rand.Next(0, 255), (byte)rand.Next(0, 255)));
                item.Height = rand.NextDouble() * 150;
                item.Margin = new Thickness(0, 8, 0, 8);
                InnerListView.Items.Add(item);
            }
        }

        private void OuterScroll_Loaded(object sender, RoutedEventArgs e)
        {
            OuterScroll.ChangeView(null, 60, null, false);
        }

        private void OuterScroll_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
        {
            if (!e.IsIntermediate)
            {
                if (OuterScroll.VerticalOffset < 60)
                {
                    if (OuterScroll.VerticalOffset <= 0.5)
                        OuterScroll.ChangeView(null, 60, null, false);
                    else
                        OuterScroll.ChangeView(null, 60, null);
                }
                if (OuterScroll.VerticalOffset <= 0.5)
                {
                    GenerateRandomListViewItem();
                }
            }
            else
            {
                double angle = (65 - OuterScroll.VerticalOffset) * 180 / 65;
                RefreshIndicatiorRotateTransform.Angle = angle;
            }

            if (OuterScroll.VerticalOffset == 0)
                RefreshIndicatiorTextBlock.Text = "Release to refresh";
            else
                RefreshIndicatiorTextBlock.Text = "Pull to refresh";
        }
    }
} 

在MainPage.xaml.cs中，我發現錯誤錯誤1找不到類型或名稱空間名稱'ScrollViewerViewChangedEventArgs'（您是否缺少using指令或程序集引用？）我應如何解決此問題？ 請分享您的建議。 提前致謝。

Answer 1

刷新視圖/屏幕的最佳方法是使用應用程序欄。 將刷新圖標放在應用程序欄中，然后在圖標上單擊以刷新視圖/屏幕。

此鏈接對使用Appication bar的幫助有幫助