动态分配 UI 权限 WPF [重复]

Posted 2023-02-23

【中文标题】动态分配 UI 权限 WPF [重复]

【英文标题】：Assign UI Permissions WPF dynamically [duplicate]

【发布时间】：2013-01-03 09:18:04

【问题描述】：

可能重复：Setting WPF UI Permissions in Code Behind

我开始使用 WPF 并希望创建一个应用程序，该应用程序将根据用户 (AD) 和他的角色(自定义) 显示/隐藏控件。

我设法通过使用继承 MarkupExpension 和 IValueConverter 的类来完成这项工作。

public class RoleToVisibilityConverter : MarkupExtension,IValueConverter

    public RoleToVisibilityConverter()
    

    

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    
        var principal = value as GenericPrincipal;
        bool IsValidUser = false;
        if (principal != null)
        
            foreach (String role in parameter.ToString().Split(';'))
            
                if (principal.IsInRole(role))
                
                    IsValidUser = true;
                    break;
                  
            
            return IsValidUser ? Visibility.Visible : Visibility.Collapsed;
        

        return null;
    

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    
        throw new NotImplementedException();
    

    public override object ProvideValue(IServiceProvider serviceProvider)
    
        return this;
    

在 XAML 中，我为可见性添加了以下绑定：

Visibility="Binding Source=x:Static systhread:Thread.CurrentPrincipal, ConverterParameter=admin;editor;readonly, Converter=rv:RoleToVisibilityConverter

注意：我还需要将 xmlns:systhread="clr-namespace:System.Threading;assembly=mscorlib" 添加到 MainWindow.xaml。

我的问题是：

上面的例子是实现这一点的最佳方式还是（正如我所想的）动态加载可见性绑定的最佳方式。

任何帮助将不胜感激。

诺埃尔。

【问题讨论】：

好的，看来我的问题有点含糊，所以重新问了一遍，得到了答案。基本上，我希望在代码隐藏中而不是在 xaml 中设置 UI 权限。看起来这不是一个好主意。在这里查看答案。 ***.com/questions/14257877/… 感谢所有回复。

【参考方案1】：

您可以尝试改用行为。我创建了一些您可以查看的简单代码：

public class Permission

    private List<string> roles = new List<string>();
    public List<string> Roles
    
        get  return roles; 
        set  roles = value; 
    


public class PermissionBehavior

    // Static behaviour parameters
    public static readonly Dictionary<FrameworkElement, PermissionBehavior> Instances = new Dictionary<FrameworkElement, PermissionBehavior>();

    public static readonly DependencyProperty PermissionProperty =
        DependencyProperty.RegisterAttached("Permission", typeof(Permission), typeof(PermissionBehavior),
                                            new PropertyMetadata(OnPermissionPropertyChanged));

    public static readonly DependencyProperty RoleProperty =
        DependencyProperty.RegisterAttached("Role", typeof(string), typeof(PermissionBehavior),
                                            new PropertyMetadata(OnRolePropertyChanged));

    private static void OnPermissionPropertyChanged(DependencyObject dependencyObject,
                                                  DependencyPropertyChangedEventArgs e)
    
        SetPermission(dependencyObject, (Permission) e.NewValue);
    

    public static void SetPermission(DependencyObject obj, Permission value)
    
        var behavior = GetAttachedBehavior(obj as FrameworkElement);
        behavior.AssociatedObject = obj as FrameworkElement;
        obj.SetValue(PermissionProperty, value);

        behavior.CurrentPermission = value;
        behavior.UpdateVisibility();
    

    public static object GetPermission(DependencyObject obj)
    
        return obj.GetValue(PermissionProperty);
    

    private static void OnRolePropertyChanged(DependencyObject dependencyObject,
                                                  DependencyPropertyChangedEventArgs e)
    
        SetRole(dependencyObject, (string) e.NewValue);
    

    public static void SetRole(DependencyObject obj, string value)
    
        var behavior = GetAttachedBehavior(obj as FrameworkElement);
        behavior.AssociatedObject = obj as FrameworkElement;
        obj.SetValue(RoleProperty, value);

        behavior.RoleList = value.Split(',').ToList();
        behavior.UpdateVisibility();
    

    public static object GetRole(DependencyObject obj)
    
        return obj.GetValue(RoleProperty);
    

    private static PermissionBehavior GetAttachedBehavior(FrameworkElement obj)
    
        if (!Instances.ContainsKey(obj))
        
            Instances[obj] = new PermissionBehavior  AssociatedObject = obj ;
        

        return Instances[obj];
    

    static PermissionBehavior()
    

    

    // Class instance parameters
    private FrameworkElement AssociatedObject  get; set; 
    private Permission CurrentPermission  get; set; 
    private List<string> RoleList  get; set; 

    private void UpdateVisibility()
    
        if(RoleList == null || CurrentPermission == null)
            return;

        if (RoleList.Intersect(CurrentPermission.Roles).Any())
        
            AssociatedObject.Visibility = Visibility.Visible;
            AssociatedObject.IsEnabled = true;
        
        else
        
            AssociatedObject.Visibility = Visibility.Hidden;
            AssociatedObject.IsEnabled = false;
        
    

XAML

<Window x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:my="clr-namespace:WpfApplication2"
    Title="MainWindow" Height="350" Width="525">
    <Grid>
        <StackPanel Orientation="Horizontal" VerticalAlignment="Top">
            <Button Content="Requires Admin" Margin="6" my:PermissionBehavior.Permission="Binding UserPermission, Mode=TwoWay" my:PermissionBehavior.Role="Admin"/>
            <Button Content="Requires User" Margin="6" my:PermissionBehavior.Permission="Binding UserPermission, Mode=TwoWay" my:PermissionBehavior.Role="User"/>
        </StackPanel>
        <Button Content="Change user" HorizontalAlignment="Left" Margin="10,88,0,0" VerticalAlignment="Top" Width="75" Click="ButtonBase_OnClick"/>

    </Grid>
</Window>

代码

public partial class MainWindow : Window, INotifyPropertyChanged


    private Permission userPermission;

    public Permission UserPermission
    
        get  return userPermission; 
        set
        
            userPermission = value;
            OnPropertyChanged("UserPermission");
        
    

    public MainWindow()
    
        InitializeComponent();
        DataContext = this;
        UserPermission = new Permission Roles = new List<string>"Admin","DumbUser";
    

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    
        var handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    

    private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
    
        var p = new Permission();
        p.Roles = new List<string> "User", "Supervisor";
        UserPermission = p;
    

我认为，用你使用的东西来改变我的 Permission 对象和逻辑是微不足道的。

【讨论】：

您好 Akselk，感谢您的回复。让你的代码运行起来，会派上用场。但我认为我的问题不够清楚。我希望避免在 xaml 中设置权限，而是将其放在后面的代码中。我想得越多，我认为这不是一个好主意。你怎么看？

谢谢！这将是有史以来最好的解决方案。