WPF issues with PasswordBox binding password (MVVM framework)

当尝试数据绑定一个PasswordBox的密码属性，你会认识到，你不能做数据就可以了绑定。 这样做的原因是，该密码属性不是由DependencyProperty支持。

原因是数据绑定密码是不是一个好的设计，出于安全考虑，应该避免。 但有时这种安全是没有必要的，那么它不但麻烦，你不能绑定到Password属性。 在这种特殊情况下，你可以利用以下PasswordBoxBindingHelper的。

<passwordbox name="pwdboxpwd"tools:PasswordBoxBindingHelper.IsPasswordBindingEnabled="True"Tools:PasswordBoxBindingHelper.BindedPassword="{Binding Path=password, Mode=twoway, updatesourcetrigger=propertychanged}"HorizontalAlignment=" Left"Height=" -"margin="167,170,0,0"Passwordchar="*"Verticalalignment="Top"Width="258"Fontsize=" -"Verticalcontentalignment="Center"Maxlength=" -"/>

Passwordboxbindinghelper is attached to PasswordBox by calling Passwordboxbindinghelper.bindedpasswordproperty. The attached property Passwordboxbindinghelper.password provides a copy of the PasswordBox control's original password property password for binding.

1   Public Static classPasswordboxbindinghelper2     {3         //Bindedpassword4          Public Static ReadOnlyDependencyProperty Bindedpasswordproperty =5Dependencyproperty.registerattached ("Bindedpassword",6             typeof(string),typeof(passwordboxbindinghelper),7             NewFrameworkpropertymetadata (string. Empty, onbindedpasswordchanged));8 9          Public Static stringGetbindedpassword (DependencyObject dp)Ten         { One             return(string) DP. GetValue (bindedpasswordproperty); A         } -          Public Static voidSetbindedpassword (DependencyObject DP,stringvalue) -         { the DP. SetValue (bindedpasswordproperty, value); -         } -  -         Private Static voidonbindedpasswordchanged (DependencyObject sender, + DependencyPropertyChangedEventArgs e) -         { +PasswordBox PasswordBox = Sender asPasswordBox; A             if(PasswordBox = =NULL) at             { -                 return; -             } -Passwordbox.passwordchanged-=passwordchanged; -  -             if(! (BOOL) getisupdating (PasswordBox)) in             { -Passwordbox.password = (string) E.newvalue; to             } +Passwordbox.passwordchanged + =passwordchanged; -         } the  *  $         //ispasswordbindingenabledPanax Notoginseng          Public Static ReadOnlyDependencyProperty Ispasswordbindingenabledproperty = -Dependencyproperty.registerattached ("ispasswordbindingenabled", the             typeof(BOOL),typeof(Passwordboxbindinghelper),NewPropertyMetadata (false, ispasswordbindingenabled)); +          Public Static voidSetispasswordbindingenabled (DependencyObject DP,BOOLvalue) A         { the DP. SetValue (ispasswordbindingenabledproperty, value); +         } -  $          Public Static BOOLgetispasswordbindingenabled (DependencyObject dp) $         { -             return(BOOL) DP. GetValue (ispasswordbindingenabledproperty); -         } the         Private Static voidispasswordbindingenabled (DependencyObject sender, - DependencyPropertyChangedEventArgs e)Wuyi         { thePasswordBox PasswordBox = Sender asPasswordBox; -  Wu             if(PasswordBox = =NULL) -                 return; About  $             if((BOOL) e.oldvalue) -             { -Passwordbox.passwordchanged-=passwordchanged; -             } A  +             if((BOOL) e.newvalue) the             { -Passwordbox.passwordchanged + =passwordchanged; $             } the         } the  the         //isupdating the         Private Static ReadOnlyDependencyProperty Isupdatingproperty = -Dependencyproperty.registerattached ("isupdating",typeof(BOOL), in            typeof(Passwordboxbindinghelper)); the  the         Private Static BOOLgetisupdating (DependencyObject dp) About         { the             return(BOOL) DP. GetValue (isupdatingproperty); the         } the  +         Private Static voidSetisupdating (DependencyObject DP,BOOLvalue) -         { the DP. SetValue (isupdatingproperty, value);Bayi         } the  the         Private Static voidPasswordChanged (Objectsender, RoutedEventArgs e) -         { -PasswordBox PasswordBox = Sender asPasswordBox; theSetisupdating (PasswordBox,true); the Setbindedpassword (PasswordBox, Passwordbox.password); theSetisupdating (PasswordBox,false); the         } -     } the}

WPF issues with PasswordBox binding password (MVVM framework)