WPF MVVM创建动态控件

在WPF中使用MVVM模式创建动态控件，可以通过以下步骤实现：

1. 定义ViewModel

首先，你需要一个ViewModel来绑定数据和命令。例如，创建一个DynamicControlsViewModel类：

using System.Collections.ObjectModel;
using System.Windows.Input;

public class DynamicControlsViewModel : INotifyPropertyChanged
{
    private ObservableCollection<ControlData> _controlsData;

    public ObservableCollection<ControlData> ControlsData
    {
        get => _controlsData;
        set
        {
            _controlsData = value;
            OnPropertyChanged(nameof(ControlsData));
        }
    }

    public DynamicControlsViewModel()
    {
        ControlsData = new ObservableCollection<ControlData>
        {
            new ControlData { Label = "Name", Value = "", ControlType = "TextBox" },
            new ControlData { Label = "Age", Value = "", ControlType = "TextBox" },
            new ControlData { Label = "Submit", Value = "", ControlType = "Button" }
        };
    }

    public event PropertyChangedEventHandler PropertyChanged;

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

public class ControlData
{
    public string Label { get; set; }
    public string Value { get; set; }
    public string ControlType { get; set; }
}

2. 创建UserControl

创建一个UserControl来动态生成控件。例如，创建一个DynamicControlsUserControl.xaml：

<UserControl x:Class="YourNamespace.DynamicControlsUserControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2006" 
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>
        <ItemsControl ItemsSource="{Binding ControlsData}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Label Content="{Binding Label}" Width="100"/>
                        <ContentControl Content="{Binding}" />
                    </StackPanel>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </Grid>
</UserControl>

在DynamicControlsUserControl.xaml.cs中：

using System.Windows.Controls;

namespace YourNamespace
{
    public partial class DynamicControlsUserControl : UserControl
    {
        public DynamicControlsUserControl()
        {
            InitializeComponent();
            this.DataContext = new DynamicControlsViewModel();
        }
    }
}

3. 在主窗口中使用UserControl

在主窗口（例如MainWindow.xaml）中，将UserControl添加到布局中：

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:YourNamespace"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <local:DynamicControlsUserControl />
    </Grid>
</Window>

4. 处理动态控件的事件

在DynamicControlsViewModel中，你可以添加命令来处理动态控件的事件。例如，处理按钮点击事件：

public class ControlData
{
    public string Label { get; set; }
    public string Value { get; set; }
    public string ControlType { get; set; }
    public ICommand ClickCommand { get; set; }

    public ControlData()
    {
        ClickCommand = new RelayCommand(OnClick);
    }

    private void OnClick(object parameter)
    {
        // 处理按钮点击事件
        Console.WriteLine($"Button {Label} clicked");
    }
}

你需要实现RelayCommand类来支持命令绑定：

using System.Windows.Input;

public class RelayCommand : ICommand
{
    private readonly Action<object> _execute;
    private readonly Predicate<object> _canExecute;

    public RelayCommand(Action<object> execute, Predicate<object> canExecute = null)
    {
        _execute = execute ?? throw new ArgumentNullException(nameof(execute));
        _canExecute = canExecute;
    }

    public bool CanExecute(object parameter)
    {
        return _canExecute == null || _canExecute(parameter);
    }

    public void Execute(object parameter)
    {
        _execute(parameter);
    }

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }
}

通过这种方式，你可以动态创建控件并处理它们的事件。