使用類綁定設置（Windows Phone）

Question

我是WP開發的新手，但有一個我無法自行解決的問題。 我正在嘗試設置一個設置頁面。 我從msdn文章中復制了大部分內容：

http://msdn.microsoft.com/en-us/library/windowsphone/develop/ff769510(v=vs.105).aspx#BKMK_CreatingaSettingsPageThatDoesNotRequireaConfirmationButton

問題連接到這條線：

<phone:PhoneApplicationPage.Resources>
  <local:Page1 x:Key="appSettings" />
</phone:PhoneApplicationPage.Resources>

它的行為完全是隨機的。 大多數情況下，VS只是崩潰。 我確定這是因為VS嘗試連接到IsolatedStorage。 但是，當我嘗試訪問該頁面時，仿真器只是關閉了該應用程序。

設置頁面（Page1）的完整代碼：
的Page1.xaml：

    <phone:PhoneApplicationPage 
    x:Class="MyApp.Page1"
    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"

    xmlns:local="clr-namespace:MyApp"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480"
    shell:SystemTray.IsVisible="True">

    <phone:PhoneApplicationPage.Resources>
      <local:Page1 x:Key="appSettings" />
    </phone:PhoneApplicationPage.Resources>


        <!--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 x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
                <TextBlock x:Name="ApplicationTitle" Text="MYAPP" Style="{StaticResource PhoneTextNormalStyle}"/>
                <TextBlock x:Name="PageTitle" Text="settings" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
            </StackPanel>
        <Grid x:Name="ContentGrid" Grid.Row="1">
            <CheckBox Content="CheckBox Setting" Height="Auto" HorizontalAlignment="Left" Margin="60,20,0,0" Name="checkBoxSetting" VerticalAlignment="Top"
            IsChecked="{Binding Source={StaticResource appSettings}, Path=CheckBoxSetting, Mode=TwoWay}"  />

            <ListBox Height="140" HorizontalAlignment="Left" Margin="70,150,0,0" Name="listBoxSetting" 
        VerticalAlignment="Top" Width="360"  SelectedIndex="{Binding Source={StaticResource appSettings}, Path=ListBoxSetting, Mode=TwoWay}">

                <ListBoxItem Content="Times New Roman" FontSize="24" FontFamily="Times New Roman" />
                <ListBoxItem Content="Arial" FontSize="24" FontFamily="Arial" />
                <ListBoxItem Content="Comic Sans MS" FontSize="24" FontFamily="Comic Sans MS" />
            </ListBox>

            <RadioButton Content="Choice One" Height="Auto" HorizontalAlignment="Left" Margin="60,0,0,235" Name="radioButton1" VerticalAlignment="Bottom" GroupName="GroupOne" IsChecked="{Binding Source={StaticResource appSettings}, Path=RadioButton1Setting, Mode=TwoWay}" />
            <RadioButton Content="Choice Two" Height="Auto" HorizontalAlignment="Left" Margin="60,350,0,0" Name="radioButton2" VerticalAlignment="Top" GroupName="GroupOne" IsChecked="{Binding Source={StaticResource appSettings}, Path=RadioButton2Setting, Mode=TwoWay}"/>
            <RadioButton Content="Choice Three" Height="Auto" HorizontalAlignment="Left" Margin="60,400,0,0" Name="radioButton3" VerticalAlignment="Top" GroupName="GroupOne" IsChecked="{Binding Source={StaticResource appSettings}, Path=RadioButton3Setting, Mode=TwoWay}"/>
        </Grid>

    </Grid>



</phone:PhoneApplicationPage>

和Page1.xaml.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;
using System.IO.IsolatedStorage;
using System.Diagnostics;



namespace Schedule
{
    public partial class Page1 : PhoneApplicationPage
    {
        // Our settings
        IsolatedStorageSettings settings;

        // The key names of our settings
        const string CheckBoxSettingKeyName = "CheckBoxSetting";
        const string ListBoxSettingKeyName = "ListBoxSetting";
        const string RadioButton1SettingKeyName = "RadioButton1Setting";
        const string RadioButton2SettingKeyName = "RadioButton2Setting";
        const string RadioButton3SettingKeyName = "RadioButton3Setting";
        const string UsernameSettingKeyName = "UsernameSetting";
        const string PasswordSettingKeyName = "PasswordSetting";

        // The default value of our settings
        const bool CheckBoxSettingDefault = true;
        const int ListBoxSettingDefault = 0;
        const bool RadioButton1SettingDefault = true;
        const bool RadioButton2SettingDefault = false;
        const bool RadioButton3SettingDefault = false;
        const string UsernameSettingDefault = "";
        const string PasswordSettingDefault = "";

        /// <summary>
        /// Constructor that gets the application settings.
        /// </summary>
        public Page1()
        {
            InitializeComponent();

            // Get the settings for this application.
            try
            {


                    settings = IsolatedStorageSettings.ApplicationSettings;


            }
            catch(System.IO.IsolatedStorage.IsolatedStorageException e)
            {
                MessageBox.Show(e.ToString());
            }

        }

        /// <summary>
        /// Update a setting value for our application. If the setting does not
        /// exist, then add the setting.
        /// </summary>
        /// <param name="Key"></param>
        /// <param name="value"></param>
        /// <returns></returns>
        public bool AddOrUpdateValue(string Key, Object value)
        {
            bool valueChanged = false;

            // If the key exists
            if (settings.Contains(Key))
            {
                // If the value has changed
                if (settings[Key] != value)
                {
                    // Store the new value
                    settings[Key] = value;
                    valueChanged = true;
                }
            }
            // Otherwise create the key.
            else
            {
                settings.Add(Key, value);
                valueChanged = true;
            }
           return valueChanged;
        }

        /// <summary>
        /// Get the current value of the setting, or if it is not found, set the 
        /// setting to the default setting.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="Key"></param>
        /// <param name="defaultValue"></param>
        /// <returns></returns>
        public T GetValueOrDefault<T>(string Key, T defaultValue)
        {
            T value;

            // If the key exists, retrieve the value.
            if (settings.Contains(Key))
            {
                value = (T)settings[Key];
            }
            // Otherwise, use the default value.
            else
            {
                value = defaultValue;
            }
            return value;
        }

        /// <summary>
        /// Save the settings.
        /// </summary>
        public void Save()
        {
            settings.Save();
        }


        /// <summary>
        /// Property to get and set a CheckBox Setting Key.
        /// </summary>
        public bool CheckBoxSetting
        {
            get
            {
                return GetValueOrDefault<bool>(CheckBoxSettingKeyName, CheckBoxSettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(CheckBoxSettingKeyName, value))
                {
                    Save();
                }
            }
        }


        /// <summary>
        /// Property to get and set a ListBox Setting Key.
        /// </summary>
        public int ListBoxSetting
        {
            get
            {
                return GetValueOrDefault<int>(ListBoxSettingKeyName, ListBoxSettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(ListBoxSettingKeyName, value))
                {
                   Save();
                }
            }
        }


        /// <summary>
        /// Property to get and set a RadioButton Setting Key.
        /// </summary>
        public bool RadioButton1Setting
        {
            get
            {
                return GetValueOrDefault<bool>(RadioButton1SettingKeyName, RadioButton1SettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(RadioButton1SettingKeyName, value))
                {    
                    Save();
                }
            }
        }


        /// <summary>
        /// Property to get and set a RadioButton Setting Key.
        /// </summary>
        public bool RadioButton2Setting
        {
            get
            {
                return GetValueOrDefault<bool>(RadioButton2SettingKeyName, RadioButton2SettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(RadioButton2SettingKeyName, value))
                {
                    Save();
                }
            }
        }

        /// <summary>
        /// Property to get and set a RadioButton Setting Key.
        /// </summary>
        public bool RadioButton3Setting
        {
            get
            {
                return GetValueOrDefault<bool>(RadioButton3SettingKeyName, RadioButton3SettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(RadioButton3SettingKeyName, value))
                {
                    Save();
                }
            }
        }

        /// <summary>
        /// Property to get and set a Username Setting Key.
        /// </summary>
        public string UsernameSetting
        {
            get
            {
                return GetValueOrDefault<string>(UsernameSettingKeyName, UsernameSettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(UsernameSettingKeyName, value))
                {
                    Save();
                }
            }
        }

        /// <summary>
        /// Property to get and set a Password Setting Key.
        /// </summary>
        public string PasswordSetting
        {
            get
            {
                return GetValueOrDefault<string>(PasswordSettingKeyName, PasswordSettingDefault);
            }
            set
            {
                if (AddOrUpdateValue(PasswordSettingKeyName, value))
                {
                    Save();
                }
            }

    }
    }
}

我會很高興獲得任何幫助。 謝謝。

Answer 1

您應該放置一個單獨的類（在MSDN示例中命名為AppSettings ，而不是local:Page1 。

在您的情況下，您已將Page1的實例放在...的XAML中。 因此，當運行時創建Page1時，它將解析XAML，查找此行代碼，創建新的Page1實例，該實例將依次創建一個Page1實例，依此類推...