不能在密封的部分类中使用外部类

Question

I am new to using C# and am attempting to build a simple windows store app right now. However I can't figure out why ArrayList cannot be found. In the following code, I attempt to use ArrayList in the Button_Click_1() function. The error I receive is " The type or namespace name 'ArrayList' could not be found ", but I am using System.Collections which is where ArrayList is included.

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The Basic Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234237

namespace Statistics
{
    /// <summary>
    /// A basic page that provides characteristics common to most applications.
    /// </summary>
    public sealed partial class MainPage : Statistics.Common.LayoutAwarePage
    {
        public MainPage()
        {
            this.InitializeComponent();
        }

        /// <summary>
        /// Populates the page with content passed during navigation.  Any saved state is also
        /// provided when recreating a page from a prior session.
        /// </summary>
        /// <param name="navigationParameter">The parameter value passed to
        /// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested.
        /// </param>
        /// <param name="pageState">A dictionary of state preserved by this page during an earlier
        /// session.  This will be null the first time a page is visited.</param>
        protected override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)
        {
        }

        /// <summary>
        /// Preserves state associated with this page in case the application is suspended or the
        /// page is discarded from the navigation cache.  Values must conform to the serialization
        /// requirements of <see cref="SuspensionManager.SessionState"/>.
        /// </summary>
        /// <param name="pageState">An empty dictionary to be populated with serializable state.</param>
        protected override void SaveState(Dictionary<String, Object> pageState)
        {
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            ArrayList data = new ArrayList();
        }

        private void TextBox_TextChanged_1(object sender, TextChangedEventArgs e)
        {

        }
    }
}

Answer 1

You are targeting windows store: that means you are using the netcore framework. This is not the regular .NET framework

• is has some things unique to it
• it lacks some things from the regular framework
• some things have different features

ArrayList is not included. Use List-of-T instead. List<object > would suffice, but a more specific type would be preferable.

Answer 2

The non-generic collections are not available in winRT (windows store) applications.

use the generic list type:

List<T>