我最近发现您应该在 WPF 中绑定(bind)密码。我在登录窗口找到了问题的答案,但我很难使用我的助手类来解决绑定(bind)问题:PasswordHelper
。此类位于我的项目文件夹之一,名为 Utils
。
这是我的 XAML 代码的一部分:
<Window x:Class="IPdevices.LoginWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:IPdevices"
xmlns:utils="clr-namespace:IPdevices.Utils;assembly=Utils"
mc:Ignorable="d"
Title="IPDevices" Height="451" Width="397.5" Icon="logo3_q2J_icon.ico">
注意 xmlns:utils="clr-namespace:IPdevices.Utils;assembly=Utils"
我的密码箱现在是
<PasswordBox utils:PasswordHelper.BindPassword="true" utils:PasswordHelper.BoundPassword="{Binding Path=NetworkPassword, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
但是,这不会编译,因为它在尖叫:
“在类型‘PasswordHelper’中找不到可附加属性‘BindPassword’。”
它也在尖叫:
“命名空间‘clr-namespace;IPdevices.Uitls;assembly=Utils’中不存在名称‘PasswordHelper’”
这是这个 PasswordHelper
类:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
namespace IPdevices.Utils
{
public static class PasswordHelper
{
public static readonly DependencyProperty BoundPassword =
DependencyProperty.RegisterAttached("BoundPassword", typeof(string), typeof(PasswordHelper), new PropertyMetadata(string.Empty, OnBoundPasswordChanged));
public static readonly DependencyProperty BindPassword = DependencyProperty.RegisterAttached(
"BindPassword", typeof(bool), typeof(PasswordHelper), new PropertyMetadata(false, OnBindPasswordChanged));
private static readonly DependencyProperty UpdatingPassword =
DependencyProperty.RegisterAttached("UpdatingPassword", typeof(bool), typeof(PasswordHelper), new PropertyMetadata(false));
private static void OnBoundPasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PasswordBox box = d as PasswordBox;
// only handle this event when the property is attached to a PasswordBox
// and when the BindPassword attached property has been set to true
if (d == null || !GetBindPassword(d))
{
return;
}
// avoid recursive updating by ignoring the box's changed event
box.PasswordChanged -= HandlePasswordChanged;
string newPassword = (string)e.NewValue;
if (!GetUpdatingPassword(box))
{
box.Password = newPassword;
}
box.PasswordChanged += HandlePasswordChanged;
}
private static void OnBindPasswordChanged(DependencyObject dp, DependencyPropertyChangedEventArgs e)
{
// when the BindPassword attached property is set on a PasswordBox,
// start listening to its PasswordChanged event
PasswordBox box = dp as PasswordBox;
if (box == null)
{
return;
}
bool wasBound = (bool)(e.OldValue);
bool needToBind = (bool)(e.NewValue);
if (wasBound)
{
box.PasswordChanged -= HandlePasswordChanged;
}
if (needToBind)
{
box.PasswordChanged += HandlePasswordChanged;
}
}
private static void HandlePasswordChanged(object sender, RoutedEventArgs e)
{
PasswordBox box = sender as PasswordBox;
// set a flag to indicate that we're updating the password
SetUpdatingPassword(box, true);
// push the new password into the BoundPassword property
SetBoundPassword(box, box.Password);
SetUpdatingPassword(box, false);
}
public static void SetBindPassword(DependencyObject dp, bool value)
{
dp.SetValue(BindPassword, value);
}
public static bool GetBindPassword(DependencyObject dp)
{
return (bool)dp.GetValue(BindPassword);
}
public static string GetBoundPassword(DependencyObject dp)
{
return (string)dp.GetValue(BoundPassword);
}
public static void SetBoundPassword(DependencyObject dp, string value)
{
dp.SetValue(BoundPassword, value);
}
private static bool GetUpdatingPassword(DependencyObject dp)
{
return (bool)dp.GetValue(UpdatingPassword);
}
private static void SetUpdatingPassword(DependencyObject dp, bool value)
{
dp.SetValue(UpdatingPassword, value);
}
}
}
我尝试过清理、重建、仔细检查所有内容,但就是无法编译。有什么见解吗?
最佳答案
This class is in one of my project's folder called Utils.
如果这意味着该类与包含 XAML 的 WPF 应用程序位于同一个项目中,那么这意味着您的 xmlns
可能是错误的。
对于当前的项目应该是:
xmlns:utils="clr-namespace:IPdevices.Utils;assembly="
或
xmlns:utils="clr-namespace:IPdevices.Utils"
关于c# - 使用 WPF 密码绑定(bind)在类型中找不到可附加属性,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39025841/