大家好,我在使用MVVM模式,我有一个名为UserViewModel的ViewModel,其中有一个名为Password的属性。在View中有一个PasswordBox控件。
<PasswordBox x:Name="txtPassword" Password="{Binding Password}" />
但是这个XAML不起作用。你如何进行绑定??请帮帮我!!
大家好,我在使用MVVM模式,我有一个名为UserViewModel的ViewModel,其中有一个名为Password的属性。在View中有一个PasswordBox控件。
<PasswordBox x:Name="txtPassword" Password="{Binding Password}" />
但是这个XAML不起作用。你如何进行绑定??请帮帮我!!
出于安全原因,Password属性不是一个依赖属性,因此您无法将其绑定。不幸的是,您需要以旧式方式在代码后台执行绑定(注册OnPropertyChanged事件并通过代码更新值...)
您可以编写一个控件来包装密码,并添加一个依赖属性以获取密码属性。
我会直接使用代码,但如果必须的话,您可以这样做:
public class BindablePasswordBox : Decorator
{
public static readonly DependencyProperty PasswordProperty =
DependencyProperty.Register("Password", typeof(string), typeof(BindablePasswordBox));
public string Password
{
get { return (string)GetValue(PasswordProperty); }
set { SetValue(PasswordProperty, value); }
}
public BindablePasswordBox()
{
Child = new PasswordBox();
((PasswordBox)Child).PasswordChanged += BindablePasswordBox_PasswordChanged;
}
void BindablePasswordBox_PasswordChanged(object sender, RoutedEventArgs e)
{
Password = ((PasswordBox)Child).Password;
}
}
BindablePasswordBox存在一个问题。它只能在一方向上工作,从PasswordBox到PasswordProperty。下面是一个修改过的版本,可以双向工作。它注册了PropertyChangedCallback并在调用时更新PasswordBox的密码。 希望有人会觉得这很有用。
public class BindablePasswordBox : Decorator
{
public static readonly DependencyProperty PasswordProperty = DependencyProperty.Register("Password", typeof(string), typeof(BindablePasswordBox), new PropertyMetadata(string.Empty, OnDependencyPropertyChanged));
public string Password
{
get { return (string)GetValue(PasswordProperty); }
set { SetValue(PasswordProperty, value); }
}
private static void OnDependencyPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
{
BindablePasswordBox p = source as BindablePasswordBox;
if (p != null)
{
if (e.Property == PasswordProperty)
{
var pb = p.Child as PasswordBox;
if (pb != null)
{
if (pb.Password != p.Password)
pb.Password = p.Password;
}
}
}
}
public BindablePasswordBox()
{
Child = new PasswordBox();
((PasswordBox)Child).PasswordChanged += BindablePasswordBox_PasswordChanged;
}
void BindablePasswordBox_PasswordChanged(object sender, RoutedEventArgs e)
{
Password = ((PasswordBox)Child).Password;
}
}
<Label>User Name</Label>
<TextBox Text="{Binding UserName}" />
<Label>Password</Label>
<PasswordBox Name="PasswordBox" />
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0 16 0 0">
<Button Margin="0 0 8 0" MinWidth="65"
Command="{Binding LoginAccept}"
CommandParameter="{Binding ElementName=PasswordBox}">
Login
</Button>
<Button MinWidth="65" Command="{Binding LoginCancel}">Cancel</Button>
</StackPanel>
public DelegateCommand<object> LoginAccept { get; private set; }
public DelegateCommand<object> LoginCancel { get; private set; }
public LoginViewModel {
LoginAccept = new DelegateCommand<object>(o => OnLogin(o), (o) => IsLoginVisible);
LoginCancel = new DelegateCommand<object>(o => OnLoginCancel(), (o) => IsLoginVisible);
}
private void OnLogin(object o)
{
var passwordBox = (o as System.Windows.Controls.PasswordBox);
var password = passwordBox.SecurePassword.Copy();
passwordBox.Clear();
ShowLogin = false;
var credential = new System.Net.NetworkCredential(UserName, password);
}
private void OnLoginCancel()
{
ShowLogin = false;
}
<Button Margin="0 0 8 0" MinWidth="65"
Command="{Binding LoginAccept}"
CommandParameter="{Binding ElementName=PasswordBox, Path=SecurePassword}">