您好，告诉我如何使用列表框中的实体框架 WPF MVVM 模式从数据库中实现数据 output

Question

能够通过 SelectItem 查看详细信息...我不明白如何正确绑定它们... 数据专用列表框 output... 而且我需要当您单击侧面的菜单项时，来自数据库的信息出现

列表框的 XAML

<ListBox Height="800" ItemsSource="{Binding ProfilesList}"></ListBox>

我的输出类

using ExperimentProjectt.DB_DIRECT;
using ExperimentProjectt.Entities;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ExperimentProjectt.Services
{
    public class ProfilesSystem
    {
        public DBContextClass _context = new();
        public List<User> GetAllUsers ()
        {
            List<User> allusers =  _context.Userss.ToList();
            return allusers;
        }
}
}

我的视图模型：

using ExperimentProjectt.DB_DIRECT;
using ExperimentProjectt.Entities;
using ExperimentProjectt.Services;
using ExperimentProjectt.ViewModels.Base;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ExperimentProjectt.ViewModels
{
    public class ProfilesViewModel:ViewModelBase
    {
        private readonly ProfilesSystem _profilesSystem;
        public ProfilesViewModel()
        {
            _profilesSystem = new ProfilesSystem();
        }

        private List<User> profileslist;

        public List<User> ProfilesList
        {
            get
            {
                return profileslist = _profilesSystem.GetAllUsers();
            }
            set
            {
                profileslist = value;
                OnPropertyChanged();
            }
        }

    }
}

Answer 1

ObservableCollection 已经有接口：INotifyCollectionChanged、INotifyPropertyChanged。

public ObservableCollection<User> ProfilesList;

ProfilesList = new ObservableCollection<User>(_profilesSystem.GetAllUsers());

private User selectedItem;
public User SelectedItem
{
    get { return selectedItem; }
    set 
    { 
        selectedItem = value;
        OnPropertyChanged();
    }
}

然后：

<ListBox SelectedItem="{Binding SelectedItem}" ItemsSource="{Binding ProfilesList}"></ListBox>

output 数据示例：

<StackPanel>
    <TextBlock Text="{Binding SelectedItem.Name}"/>
    <TextBlock Text="{Binding SelectedItem.Username}"/>
    <TextBlock Text="{Binding SelectedItem.Age}"/>
</StackPanel>