WPF实现数据读取与绑定的详细步骤

// ❌ 致命错误：未设置DataContext
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        // 错误：未设置DataContext
    }
}

// ✅ 正确写法：在构造函数中设置DataContext
public MainWindow()
{
    InitializeComponent();
    this.DataContext = new UserViewModel(); // 设置数据源
}

// ❌ 无通知的模型
public class Patient
{
    public string Name { get; set; } // 修改后UI不更新
}

// ✅ 实现INotifyPropertyChanged
public class Patient : INotifyPropertyChanged
{
    private string _name;
    public string Name
    {
        get { return _name; }
        set
        {
            if (_name != value)
            {
                _name = value;
                OnPropertyChanged(nameof(Name)); // 触发更新
            }
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class User
{
    public string Username { get; set; }
    public int Age { get; set; }
}

this.DataContext = new User { Username = "Alice", Age = 25 };

<TextBox Text="{Binding Username}" />
<Label Content="{Binding Age}" />

public class UserViewModel
{
    public ObservableCollection<User> Users { get; set; } = new ObservableCollection<User>();
}

// XAML
<ListBox ItemsSource="{Binding Users}" DisplayMemberPath="Username" />

<Window.Resources>
    <CollectionViewSource x:Key="FilteredUsers" Source="{Binding Users}" />
</Window.Resources>
<ListBox ItemsSource="{Binding Source={StaticResource FilteredUsers}}" />

<TextBox Text="{Binding Username, Mode=TwoWay}" />

<TextBox Text="{Binding Username, UpdateSourceTrigger=PropertyChanged}" />

public class MyBrush : SolidColorBrush, IFreezable
{
    public override void Freeze()
    {
        base.Freeze();
    }
}

BindingGroup bindingGroup = new BindingGroup();
bindingGroup.Add(new Binding("Username") { Source = user });
bindingGroup.Add(new Binding("Password") { Source = user });