Workarounds for PasswordBox bindings under Mvvmlight

In the company's project, using the Mvvmlight framework, you need to do a login registration function module, but in WPF PasswordBox has no built-in binding functionality, because of security considerations. However, bloggers also very want to fit the MVVM idea, must passwordbox in the view binding to the ViewModel, after the online search, as well as many experiments, finally succeeds. Hereby record.

(Development environment: Vs2015+ef+mvvmlight+sql server2016)

First build a helper class:

    public class Passwordbindinghelper {public static readonly DependencyProperty Passwordproperty = Dep Endencyproperty.registerattached ("Password", typeof (String), typeof (Passwordbindinghelper), new Frameworkpro Pertymetadata (String.        Empty, onpasswordpropertychanged));            public static readonly DependencyProperty Attachproperty = dependencyproperty.registerattached ("Attach",        typeof (BOOL), typeof (Passwordbindinghelper), new PropertyMetadata (False, Attach)); private static readonly DependencyProperty Isupdatingproperty = dependencyproperty.registerattached ("isupdating"        , typeof (BOOL), typeof (Passwordbindinghelper)); public static void Setattach (DependencyObject DP, BOOL value) {DP.        SetValue (attachproperty, value); public static bool Getattach (DependencyObject DP) {return (BOOL) DP.        GetValue (Attachproperty); } public static string GETPAssWOrd (DependencyObject dp) {return (string) DP.        GetValue (Passwordproperty); public static void SetPassword (DependencyObject dp, String value) {DP.        SetValue (passwordproperty, value); } private static bool Getisupdating (DependencyObject DP) {return (BOOL) DP.        GetValue (Isupdatingproperty); } private static void Setisupdating (DependencyObject DP, BOOL value) {DP.        SetValue (isupdatingproperty, value); } private static void Onpasswordpropertychanged (DependencyObject sender, Dependencypropertychangedeventa            RGS e) {PasswordBox PasswordBox = sender as PasswordBox;            Passwordbox.passwordchanged-= passwordchanged; if (! (            BOOL) getisupdating (PasswordBox)) {Passwordbox.password = (string) e.newvalue;        } passwordbox.passwordchanged + = passwordchanged; } private Static void Attach (DependencyObject sender, DependencyPropertyChangedEventArgs e) {PasswordBox PA            Sswordbox = sender as PasswordBox;            if (PasswordBox = = null) return;            if (bool) e.oldvalue) {passwordbox.passwordchanged-= passwordchanged;            } if ((bool) e.newvalue) {passwordbox.passwordchanged + = passwordchanged; }} private static void PasswordChanged (object sender, RoutedEventArgs e) {PasswordBox P            Asswordbox = sender as PasswordBox;            Setisupdating (PasswordBox, true);            SetPassword (PasswordBox, Passwordbox.password);        Setisupdating (PasswordBox, false); }    }

View:

<Pagex:class= "Sggs." SmartGroundGuidence.Pages.LoginPage "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:sggs." Smartgroundguidence.pages "Xmlns:helper= "Clr-namespace:sggs.smartgroundguidence.commonhelper"mc:ignorable= "D"Title= "LoginPage">    <Page.datacontext>        <BindingPath= "LoginPage"Source="{StaticResource Locator}"></Binding>    </Page.datacontext>    <GridVerticalAlignment= "Top"Width= "+"Height= "417">        <Grid.background>            <ImageBrushImageSource= "Resources/bg_login_popup.png" />        </Grid.background>        <grid.rowdefinitions>            <RowDefinitionHeight= "$"></RowDefinition>            <RowDefinitionHeight= "+"></RowDefinition>            <RowDefinitionHeight= " the"></RowDefinition>            <RowDefinitionHeight= "+"></RowDefinition>            <RowDefinitionHeight= "+"></RowDefinition>            <RowDefinitionHeight= "$"></RowDefinition>            <RowDefinitionHeight= "$"></RowDefinition>            <RowDefinitionHeight= "The "></RowDefinition>            <RowDefinitionHeight= "The "></RowDefinition>        </grid.rowdefinitions>        <StackPanelGrid.Row= "1">            <GridHeight= "+"Width= "404">                <grid.columndefinitions>                    <ColumnDefinitionWidth= "115*"></ColumnDefinition>                    <ColumnDefinitionWidth= "289*"></ColumnDefinition>                </grid.columndefinitions>                <TextBoxGrid.column= "0"Grid.columnspan= "2"Style="{StaticResource Slttxtlogin}"Text="{Binding loginuser.username,updatesourcetrigger=propertychanged}"/>                <LabelGrid.column= "0"FontSize= "+"Foreground= "White"Content= "User name"VerticalAlignment= "Center"HorizontalAlignment= "Center"/>            </Grid>        </StackPanel>        <StackPanelGrid.Row= "3">            <GridHeight= "+"Width= "404">                <grid.columndefinitions>                    <ColumnDefinitionWidth= "115*"></ColumnDefinition>                    <ColumnDefinitionWidth= "289*"></ColumnDefinition>                </grid.columndefinitions>                <PasswordBoxGrid.column= "0"Grid.columnspan= "2"Style="{StaticResource Sltpwblogin}"MaxLength= " the"Helper:PasswordBindingHelper.Password="{Binding password,mode=twoway,updatesourcetrigger=propertychanged}"/>                <LabelGrid.column= "0"FontSize= "+"Foreground= "White"Content= "Password"VerticalAlignment= "Center"HorizontalAlignment= "Center"/>            </Grid>        </StackPanel>        <StackPanelGrid.Row= "5">            <GridWidth= "404">                <CheckBoxStyle="{StaticResource Mycheckboxstyle}"HorizontalAlignment= "Left"Margin= "15,0,0,0"IsChecked="{x:null}"></CheckBox>            </Grid>        </StackPanel>        <StackPanelGrid.Row= "7"Orientation= "Horizontal"HorizontalAlignment= "Center">            <ButtonStyle="{StaticResource Stlbtnlogin}" />            <ButtonStyle="{StaticResource Stlbtnregister}"Margin= "72,0,0,0"/>        </StackPanel>    </Grid></Page>

The rest of the model and ViewModel and Viewmodellocator are mvvmlight, not related to this article, and are recorded here.

Workarounds for PasswordBox bindings under Mvvmlight