ComboBox绑定到自定义视图模型

我正在做一个WPF项目。这是我的XAML代码:

<Window x:Class="MyNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
        xmlns:l="clr-namespace:MyNamespace" 
        xmlns:p="clr-namespace:MyNamespace.Properties"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
        Height="500" Title="{x:Static p:Resources.Title}" Width="500"
        WindowStartupLocation="CenterScreen">
    <Window.Resources>
        <l:BrowsersViewModel x:Key="BrowsersViewModel"/>
    </Window.Resources>
    <Canvas Background="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"
            DataContext="{StaticResource BrowsersViewModel}">
        <ComboBox Canvas.Left="10" Canvas.Top="10" DisplayMemberPath="Name"
                  ItemsSource="{Binding Path=Items}" 
                  SelectedItem="{Binding Mode=TwoWay, Path=SelectedItem}"
                  SelectedValuePath="Process" Width="379"/>
        <Button Content="Repopulate" Canvas.Right="10" 
                Canvas.Top="10" Width="75"/>
    </Canvas>
</Window>

// BrowserInstance is a simple struct with two public fields:
// 1) System.Diagnostics.Process Process
// 2) System.String Name
public sealed class BrowsersViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    private BrowserInstance m_SelectedItem;
    public BrowserInstance SelectedItem
    {
        get { return m_SelectedItem; }
        set
        {
            if (m_SelectedItem != value)
            {
                m_SelectedItem = value;
                NotifyPropertyChanged("SelectedItem");
            }
        }
    }
    private ObservableCollection<BrowserInstance> m_Items;
    public ObservableCollection<BrowserInstance> Items
    { 
        get { return m_Items; }
        set
        {
            if (m_Items != value)
            {
                m_Items = value;
                NotifyPropertyChanged("Items");
            }
        }
    }
    public BrowsersViewModel()
    {
        m_Items = new ObservableCollection<BrowserInstance>();
        Populate();
    }
    private void NotifyPropertyChanged(String propertyName)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, (new PropertyChangedEventArgs(propertyName)));
    }
    public void Populate()
    {
        foreach (Process process in Process.GetProcessesByName("chrome"))
        {
            BrowserInstance instance = new BrowserInstance();
            instance.Process = process;
            instance.Name = "[Chrome] " 
                         + process.Handle.ToString() 
                         + " " + ((process.MainWindowTitle.Length > 0) ? 
                                        process.MainWindowTitle : "NULL");
            m_Items.Add(instance);
        }
        NotifyPropertyChanged("Items");
    }
}

我真的很难让这个工作。我看了无数的例子，我仍然找不到一个解决方案，使一切工作如预期。

1)我看到很多值在我的组合框下拉，但他们都是空的。我想在ComboBox中显示BrowserInstance.Name属性，并在选择项目时检索BrowserInstance.Process值。

2)当应用程序启动时，对当前正在运行的浏览器进程进行检查，以便填充ComboBox。如果没有找到正在运行的实例，我如何在我的组合框中显示"没有找到实例!"这样的消息?

3)如果在应用程序启动时发现一个或多个浏览器实例，我如何默认选择第一个?

4) Repopulate按钮将用于重新检查用户正在运行的浏览器实例。假设之前选择的实例仍在运行…我怎样才能使它保持选中状态?如果之前选择的实例不再运行，那么如何在默认情况下再次选择第一个实例呢?

多谢!

编辑:这是我当前的代码

主窗口:

public MainWindow()
{
    InitializeComponent();
    DataContext = m_BrowserInstances = new BrowserInstancesViewModel();
}
private void OnClickButtonRefresh(Object sender, RoutedEventArgs e)
{
    m_BrowserInstances.Populate();
}

BrowserInstancesViewModel:

public void Populate()
{
    BrowserInstance selectedItem = m_SelectedItem;
    List<BrowserInstance> items = new List<BrowserInstance>();
    foreach (Process process in Process.GetProcessesByName("chrome"))
        items.Add(new BrowserInstance(process));
    if (items.Count > 0)
    {
        m_Items = new ObservableCollection<BrowserInstance>(items.OrderBy(x => x.Process.Id));
        if ((selectedItem != null) && (m_Items.SingleOrDefault(NewMethod(selectedItem)) != null))
            m_SelectedItem = selectedItem;
        else
            m_SelectedItem = m_Items[0];
        m_Enabled = true;
    }
    else
    {
        m_Items = new ObservableCollection<BrowserInstance>() { (new BrowserInstance()) };
        m_SelectedItem = m_Items[0];
        m_Enabled = false;
    }
    NotifyPropertyChanged("Enabled");
    NotifyPropertyChanged("Items");
    NotifyPropertyChanged("SelectedItem");
}