將ListBox綁定到靜態列表並創建DataTemplate

Question

我使用靜態成員列表創建了以下類：

public class Role
{
    public static List<Role> AllRoles = new List<Role>()
    {
        Administrators,
        PowerUsers,
        Limited
    };

    public static Role Administrators = new Role() { Name = "Bob" };
    public static Role PowerUsers = new Role() { Name = "Jimbo" };
    public static Role Limited = new Role() { Name = "Jack" };

    public string Name { get; set; }
}

現在我正在嘗試使用基於每個屬性的項目模板在ListBox中綁定它。 我無法使綁定工作，它不返回值。

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WPFTests">

    <Grid>
        <ListBox Width="200" Height="200"
                 ItemsSource="{Binding Source={x:Static local:Role.AllRoles}}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <CheckBox Content="{Binding Path=Name}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>

我一定很遺憾。 我得到3個復選框來表示3個成員的數組，但我沒有得到任何綁定到公共屬性的結果。

Answer 1

如果您像這樣重新排列代碼，它可以工作：

public class Role 
{ 
    public static List<Role> AllRoles = new List<Role>() 
    { 
        Administrators, 
        PowerUsers, 
        Limited 
    }; 

    public static Role Administrators = new Role() { Name = "Bob" }; 
    public static Role PowerUsers = new Role() { Name = "Jimbo" }; 
    public static Role Limited = new Role() { Name = "Jack" }; 

    public string Name { get; set; } 
} 

您不應該依賴於初始化靜態字段的特定順序。 根據http://msdn.microsoft.com/en-us/library/aa645758(v=vs.71).aspx ，靜態字段初始化的順序是未定義的。

使用靜態構造函數，代碼可能更具可讀性：

public class Role
{
    public static Role Administrators;
    public static Role PowerUsers;
    public static Role Limited;

    public static List<Role> AllRoles;

    static Role()
    {
        Administrators = new Role() {Name = "Bob"};
        PowerUsers = new Role() {Name = "Jimbo"};
        Limited = new Role() {Name = "Jack"};

        AllRoles = new List<Role>()
            {
                Administrators,
                PowerUsers,
                Limited
            };
    }

    public string Name { get; set; }
}