0

这是我试图加载数据的类

第 2 页 XAML

   <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"
    d:DataContext="{d:DesignData SampleData/MainViewModelSampleData.xaml}"
    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.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel Grid.Row="0" Margin="12,17,0,28">
            <TextBlock Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Margin="0,10,0,0" Grid.Row="1">

            <phone:LongListSelector x:Name="MainLongListSelector" Margin="10,2,0,0" ItemsSource="{Binding Items2}" SelectionChanged="MainLongListSelector_SelectionChanged">
                <phone:LongListSelector.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Margin="0,0,0,17" Height="154">
                            <TextBlock Text="{Binding LineOne}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" FontSize="20" Margin="0,0,0,538" Height="150"/>
                        </StackPanel>
                    </DataTemplate>
                </phone:LongListSelector.ItemTemplate>


            </phone:LongListSelector>


        </Grid>
    </Grid>

</phone:PhoneApplicationPage>

主视图模型

using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using Package_Tracker_P.Resources;
using System.Collections.Generic;
using Windows.Storage;
using System.IO;
using System.Threading.Tasks;
using System.Windows;
using System.Text.RegularExpressions;

namespace Package_Tracker_P.ViewModels
{
    public class MainViewModel : INotifyPropertyChanged
    {
        public static List<Car> carlist = new List<Car>();

        public MainViewModel()
        {
            this.Items = new ObservableCollection<ItemViewModel>();
            this.Items2 = new ObservableCollection<ItemViewModel>();
        }

        /// <summary>
        /// A collection for ItemViewModel objects.
        /// </summary>


        public ObservableCollection<ItemViewModel> Items { get; private set; }
        public ObservableCollection<ItemViewModel> Items2 { get; private set; }


        private string _sampleProperty = "Sample Runtime Property Value";
        /// <summary>
        /// Sample ViewModel property; this property is used in the view to display its value using a Binding
        /// </summary>
        /// <returns></returns>
        public string SampleProperty
        {
            get
            {
                return _sampleProperty;
            }
            set
            {
                if (value != _sampleProperty)
                {
                    _sampleProperty = value;
                    NotifyPropertyChanged("SampleProperty");
                }
            }
        }

        /// <summary>
        /// Sample property that returns a localized string
        /// </summary>
        public string LocalizedSampleProperty
        {
            get
            {
                return AppResources.SampleProperty;
            }
        }

        public bool IsDataLoaded
        {
            get;
            private set;
        }

        /// <summary>
        /// Creates and adds a few ItemViewModel objects into the Items collection.
        /// </summary>
        public async void LoadData(Car toyota)
        {
            // Sample data; replace with real data
            carlist.Add(toyota);
            this.Items.Add(new ItemViewModel() { ID = (Items.Count.ToString()), LineOne = toyota.status, LineTwo = "", LineThree = "" });
            this.IsDataLoaded = true;
            //await openfile();
            await IO.WriteToFile();
        }

 public async void LoadData()
        {
            try
            {
                stuff();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error Loading Data");
            }
        }
        public void stuff()
        {
            this.Items2.Add(new ItemViewModel() { ID = (Items2.Count.ToString()), LineOne = "Auto Detect", LineTwo = "", LineThree = "" });
            this.IsDataLoaded = true;
        }


        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged(String propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}

问题是没有加载 PAGE2 的数据。它正在使用 items1 为主页加载它。当应用程序正在加载时，它调用 LoadData() 并调用 stuff() 将数据添加到 items2。它在文本块中的 PAGE TWO 的 xaml 文件中正确绑定。我错过了什么吗？

4

1 回答 1

0

我认为这段代码的主要问题是你没有设置第 2 页的数据上下文，就像你使用 MVVM light 那样

DataContext = {Binding MainViewModel,Source="{StaticResource Locator}}"
于 2013-07-09T04:57:34.053 回答