c＃wpf：无法将项目添加到组合框

Question

I've a combobox in which I try to add the current processes(its window title). My code is:

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    List<ComboBoxItem> list = new List<ComboBoxItem>();
    ComboBoxItem item;
    Process[] _processes = Process.GetProcesses();
    foreach (Process process in _processes)
    {
        item = new ComboBoxItem();
        item.Content = process.MainWindowTitle;
        item.ToolTip = process.MainWindowTitle;

        list.Add(item)
    }

    cbProcesses.ItemsSource = list;
}

And XAML:

<ComboBox x:Name="cbProcesses" HorizontalAlignment="Left" Margin="101,40,0,0" VerticalAlignment="Top" Width="120" SelectionChanged="comboProcesses_Selected" IsSynchronizedWithCurrentItem="True" SelectedIndex="0">
            <ComboBox.ItemContainerStyle>
                <Style TargetType="ComboBoxItem" BasedOn="{StaticResource {x:Type ComboBoxItem}}">
                    <EventSetter Event="MouseEnter" Handler="cbProcesses_MouseEnter" />
                </Style>
            </ComboBox.ItemContainerStyle>
</ComboBox>

It crashes when is trying cbProcesses.ItemsSource = list . What could I do?

Answer 1

This works for me perfect:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ComboBox x:Name="cbProcesses" HorizontalAlignment="Left" Margin="101,40,0,0" VerticalAlignment="Top" Width="120" IsSynchronizedWithCurrentItem="True" SelectedIndex="0">
            <ComboBox.ItemContainerStyle>
                <Style TargetType="ComboBoxItem" BasedOn="{StaticResource {x:Type ComboBoxItem}}">
                    <EventSetter Event="MouseEnter" Handler="cbProcesses_MouseEnter" />
                </Style>
            </ComboBox.ItemContainerStyle>
        </ComboBox>
    </Grid>
</Window>

C#:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    /// <summary>
    /// Interaktionslogik für MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            this.Loaded += MainWindow_Loaded;
        }

        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            List<ComboBoxItem> list = new List<ComboBoxItem>();
            ComboBoxItem item;
            Process[] _processes = Process.GetProcesses();
            foreach (Process process in _processes)
            {
                if (!String.IsNullOrEmpty(process.MainWindowTitle))
                {
                    item = new ComboBoxItem();
                    item.Content = process.MainWindowTitle;
                    item.ToolTip = process.MainWindowTitle;

                    list.Add(item);
                }
            }

            cbProcesses.ItemsSource = list;
        }

        private void cbProcesses_MouseEnter(object sender, MouseEventArgs e)
        {

        }
    }
}

I just added: if (!String.IsNullOrEmpty(process.MainWindowTitle))