一、目的：本身自带的PassWord不支持绑定

二、Xaml部分

<UserControl x:Class="HeBianGu.General.WpfControlLib.BindPassWordBox"



             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/2008" 



             xmlns:local="clr-namespace:HeBianGu.General.WpfControlLib"




             mc:Ignorable="d" 



             d:DesignHeight="50" d:DesignWidth="300">



    <Grid>




        <PasswordBox x:Name="pb_center" PasswordChanged="pb_center_PasswordChanged" />




    </Grid>




</UserControl>

三、代码部分

/// <summary> 可以绑定的密码框 </summary>



    public partial class BindPassWordBox : UserControl




    {



        PasswordBox _password = null;







        private void pb_center_PasswordChanged(object sender, RoutedEventArgs e)




        {



            this.PassWord = this._password.Password;



        }











        public BindPassWordBox()




        {



            InitializeComponent();



        }







        public string PassWord



        {



            get { return (string)GetValue(PassWordProperty); }



            set { SetValue(PassWordProperty, value); }



        }







        // Using a DependencyProperty as the backing store for MyProperty.  This enables animation, styling, binding, etc...




        public static readonly DependencyProperty PassWordProperty =



            DependencyProperty.Register("PassWord", typeof(string), typeof(BindPassWordBox), new PropertyMetadata(default(string), (d, e) =>



             {



                 BindPassWordBox control = d as BindPassWordBox;







                 if (control == null) return;







                 string config = e.NewValue as string;







                 if (control._password == null) return;







                 control._password.Password = config;







                 SetPasswordBoxSelection(control._password, config.Length, 0);



             }));











        private static void SetPasswordBoxSelection(PasswordBox passwordBox, int start, int length)




        {



            var select = passwordBox.GetType().GetMethod("Select",



                            BindingFlags.Instance | BindingFlags.NonPublic);







            select.Invoke(passwordBox, new object[] { start, length });



        }



    }

四、原理

封装一层PassWordBox控件，自定义依赖属性，在PassWordBox的Changed事件中赋值依赖属性

SetPasswordBoxSelection(control._password, config.Length, 0);

此方法用来设置光标，否则输入后光标位置不正确

封装：WPF中可以绑定的BindPassWord控件