WPF 多路绑定

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;


namespace XamlTest
{
    /// <summary>
    /// Interaction logic for Window17.xaml
    /// </summary>
    public partial class Window17 : Window
    {
        public Window17()
        {
            InitializeComponent();
            Binding b1 = new Binding("Text") { Source = txt1 };
            Binding b2 = new Binding("Text") { Source = txt2 };
            Binding b3 = new Binding("Text") { Source = txt3 };
            Binding b4 = new Binding("Text") { Source = txt4 };
            MultiBinding mb = new MultiBinding();
            mb.Bindings.Add(b1);
            mb.Bindings.Add(b2);
            mb.Bindings.Add(b3);
            mb.Bindings.Add(b4);
            mb.Converter = new MultiBindingConverter();
            btn.SetBinding(Button.IsEnabledProperty, mb);
            
        }
    }

}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;


namespace XamlTest
{
    public class MultiBindingConverter:IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (!values.Cast<string>().Any(s=>string.IsNullOrEmpty(s)) && values[0].ToString()==values[1].ToString() && values[2].ToString()==values[3].ToString())
            {
                return true;
            }
            return false;
        }


        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}