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我想在點擊按鈕期間將TreeView的綁定的數據類型更改爲另一種類型。更改WPF TreeView的數據類型ItemsSource
這是TreeView的代碼聲明。我想將角色類型從StudentRoles更改爲BursarRoles。例如：
<local:StudentRoles x:Key="MyData" />
到
<local:BursarRoles x:Key="MyData" />
TreeView定義：
<UserControl.Resources>
<local:StudentRoles x:Key="MyData" />
<DataTemplate x:Key="LevelFour">
<Border CornerRadius="5" >
<StackPanel Opacity=" 3">
<TextBlock Text="{Binding Path=Name}"
Margin="5 5"
FontFamily="{StaticResource LatoRegular}"
FontSize="{StaticResource FontSizeMedium}"
Foreground="{StaticResource ForegroundVeryDarkBrush}"
/>
</StackPanel>
</Border>
</DataTemplate>
<HierarchicalDataTemplate x:Key="LevelThree"
ItemsSource="{Binding SubRoles}"
ItemTemplate="{StaticResource LevelFour}"
>
<StackPanel Margin="0 3">
<TextBlock Text="{Binding Path=Name}"
Margin="2"
Foreground="{StaticResource ForegroundVeryDarkBrush}"
FontFamily="{StaticResource LatoRegular}"
FontSize="{StaticResource FontSizeMedium}"
/>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="LevelTwo"
ItemsSource="{Binding Roles}"
ItemTemplate="{StaticResource LevelThree}"
>
<StackPanel Margin="0 3">
<TextBlock Text="{Binding Path=RoleDescription}"
Margin="2"
Foreground="{StaticResource ForegroundVeryDarkBrush}"
FontFamily="{StaticResource LatoRegular}"
FontSize="{StaticResource FontSizeLarge}"
/>
</StackPanel>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="LevelOne"
ItemsSource="{Binding UserRoles}"
ItemTemplate="{StaticResource LevelTwo}"
>
<StackPanel Margin="0 3">
<TextBlock Text="{Binding Path=UserDescription}"
Margin="2"
Foreground="{StaticResource WordOrangeBrush}"
FontFamily="{StaticResource LatoRegular}"
FontSize="{StaticResource FontSizeXLarge}"
/>
</StackPanel>
</HierarchicalDataTemplate>
</UserControl.Resources>
<Grid x:Name="CanScrolGrid">
<TreeView ItemTemplate="{StaticResource LevelOne}"
ItemsSource="{StaticResource MyData}"
Background="{StaticResource ForegroundLightBrush}"
/>
<Button Margin="10" HorizontalAlignment="Center" Height="40" Width="170"
Background="{StaticResource WordBlueBrush}"
Content="Change Roles" Click="Button_Click" />
</Grid>
的UserControl套控制角色的列表的DataContext，如StudentRoles在這背後的代碼案例：
public partial class RoleControls : UserControl
{
public RoleControls()
{
InitializeComponent();
this.DataContext = new StudentRoles();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
}
}
角色單獨工作正常，但我希望能夠在運行時將數據上下文更改爲不同的角色。但我不能做很容易，因爲這行：
<local:StudentRoles x:Key="MyData" />
我怎麼能替換一條線，將允許更改DataContext這條線？
下面是角色的樣本列表（StudentRoles）：
/// <summary>
/// The roles a student can perform on the system
/// </summary>
public class StudentRoles : BaseRole
{
#region Constructor
/// <summary>
/// Default Constructor
/// </summary>
public StudentRoles()
{
RoleType roleType;
Role role;
Role subRole;
UserType userRoles = new UserType("Student");
#region Student Management
roleType = new RoleType("Stock Management");
// Register product
role = new Role("Register Product");
// Single
subRole = new Role("Single");
role.SubRoles.Add(subRole);
// Multiple
subRole = new Role("Multiple");
role.SubRoles.Add(subRole);
roleType.Roles.Add(role);
// Update product Status
role = new Role("Update Product Details");
// Single
subRole = new Role("Single");
role.SubRoles.Add(subRole);
// Multiple
subRole = new Role("Multiple");
role.SubRoles.Add(subRole);
roleType.Roles.Add(role);
// View Product
role = new Role("View Product Details");
// Single
subRole = new Role("Single");
role.SubRoles.Add(subRole);
// by Brand
subRole = new Role("By Brand");
role.SubRoles.Add(subRole);
// bY level
subRole = new Role("By Price");
role.SubRoles.Add(subRole);
// by business Year
subRole = new Role("By Business Year");
role.SubRoles.Add(subRole);
// Dismiss product
role = new Role("Delete Product");
// Single
subRole = new Role("Single");
role.SubRoles.Add(subRole);
// Multiple
subRole = new Role("Multiple");
role.SubRoles.Add(subRole);
// Add the role the list of role type
roleType.Roles.Add(role);
userRoles.UserRoles.Add(roleType);
this.Add(userRoles);
#endregion
}
#endregion
}