c# - MVVM丢失，尝试将M连接到VM到V

Question

所以这就是我想要做的。我想将字符串techName从模型传递到 View ...，但我不了解如何执行此操作。我可以从ViewModel到 View 完成此操作，但我希望数据位于Model中并由ViewModel提取并传递给View。以便可以跨多个 View 使用数据。话是这么说
主窗口:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void DefaultViewClicked(object sender, RoutedEventArgs e)
    {
       DataContext = new DefaultViewModel();
    }

    private void NewCallClicked(object sender, RoutedEventArgs e)
    {
        DataContext = new NewCallViewModel();
    }
}

看法:

Text="{Binding model.TechName}

ViewModel:

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
using callFlow.Models;


namespace callFlow.ViewModels
{
    public class DefaultViewModel
    {
        private ObservableCollection<DataModel> model = new ObservableCollection<DataModel>();

        public DefaultViewModel() { }

        private DataModel _selectedModel;
        public DataModel SelectedModel
        {
            get { return _selectedModel ?? (_selectedModel = new SelectedModel()); }
            set { _selectedModel = value; }
        }

        public void changeSelectedModel(DataModel newSelectedModel)
        {
            SelectedModel.TechName = newSelectedModel.TechName;
        }
    }
}

模型:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Text;
using System.Drawing;

namespace callFlow.Models
{
    public class DataModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private string techName ="this is a test";

        public DataModel()
        {

        }

        public string TechName
        {
            get { return techName; }
            set { techName = value; OnPropertyChanged(); }
        }

        protected void OnPropertyChanged([CallerMemberName] string techName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(techName));
        }
    }
}

Answer 1

您的Datacontext类DefaultViewModel没有任何model属性。
因此，您必须用以下代码替换XAML:

Text="{Binding SelectedModel.TechName}