wpf listbox中添加checkbox实现多选，listbox绑定的数据源是list<string>，并将选中的值传入后台，使用mvvm模型，给出示例代码

可以使用以下代码实现：

在 XAML 中：

<ListBox ItemsSource="{Binding MyList}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}" />
<TextBlock Text="{Binding}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

在 ViewModel 中：

public class MyViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;

private List<MyItem> _myList;
public List<MyItem> MyList
{
get { return _myList; }
set
{
_myList = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(MyList)));
}
}

public ICommand SaveCommand { get; }

public MyViewModel()
{
MyList = new List<MyItem>
{
new MyItem { Text = "Item 1" },
new MyItem { Text = "Item 2" },
new MyItem { Text = "Item 3" }
};

SaveCommand = new RelayCommand(Save);
}

private void Save()
{
var selectedItems = MyList.Where(x => x.IsSelected).Select(x => x.Text);
// 将选中的值传入后台
}
}

public class MyItem : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;

private bool _isSelected;
public bool IsSelected
{
get { return _isSelected; }
set
{
_isSelected = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsSelected)));
}
}

public string Text { get; set; }
}

其中，RelayCommand 是一个实现了 ICommand 接口的类，用于绑定按钮的 Command 属性。