c# - 如何强制验证在 UserControl 上显示

Question

我希望带有工具提示的库存/标准红色边框验证显示在我的 UserControl 周围。请参阅下面的代码。我有主页和用户控件。

UserControl 有文本框和按钮。UserControls 绑定到 Id 属性并在 TextBox 中显示此 Id。

主页有 UserControl 和 TextBox。它们绑定到 FirstValue 和 SecondValue。这两个属性都会引发错误。当我在文本框中输入/更改某些内容时 - 我看到了边框和摘要。当我在 UserControl 中更改文本时 - 我在摘要中看到错误但没有边框，当我点击错误时 - 它聚焦按钮，不会转到 TextBox。我该如何解决？我希望整个 UserControl 都在红色边框内。

主页 XAML：

<UserControl x:Class="SilverlightApplication1.MainPage"
    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"
    mc:Ignorable="d"
    d:DesignHeight="275" d:DesignWidth="402" xmlns:my="clr-namespace:SilverlightApplication1" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">

    <Grid x:Name="LayoutRoot" Background="White" Width="300" HorizontalAlignment="Left">
        <Grid.RowDefinitions>
            <RowDefinition Height="30" />
            <RowDefinition Height="40" />
            <RowDefinition Height="30" />
            <RowDefinition Height="30" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <TextBox Grid.Row="2" Margin="3" Text="{Binding SecondValue, Mode=TwoWay, NotifyOnValidationError=True}"/>
        <my:TestUserControl Margin="3" Id="{Binding FirstValue, Mode=TwoWay, NotifyOnValidationError=True}"/>
        <sdk:ValidationSummary Grid.Row="4" Name="validationSummary1" />
    </Grid>
</UserControl>

主页 CS

using System.Windows.Controls;


namespace SilverlightApplication1
{
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Linq;

    public partial class MainPage : UserControl, INotifyDataErrorInfo, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
        readonly Dictionary<string, List<string>> _currentErrors;

        private string _firstValue;
        private string _secondValue;

        public MainPage()
        {
            InitializeComponent();
            _currentErrors = new Dictionary<string, List<string>>();
            _firstValue = "test1";
            _secondValue = "test2";
            LayoutRoot.DataContext = this;
        }


        public string FirstValue
        {
            get { return _firstValue; }

            set
            {
                _firstValue = value;
                CheckIfValueIsValid("FirstValue", value);
                this.OnPropertyChanged("FirstValue");
            }
        }

        public string SecondValue
        {
            get { return _secondValue; }
            set
            {
                _secondValue = value;
                CheckIfValueIsValid("SecondValue", value);
                this.OnPropertyChanged("SecondValue");
            }
        }

        public void CheckIfValueIsValid(string propertyName, string value)
        {
            ClearErrorFromProperty(propertyName);

            AddErrorForProperty(propertyName, "Bad value");
        }

        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public IEnumerable GetErrors(string propertyName)
        {
            if (string.IsNullOrEmpty(propertyName))
            {
                return (_currentErrors.Values);
            }
            MakeOrCreatePropertyErrorList(propertyName);

            return _currentErrors[propertyName];
        }

        public bool HasErrors
        {
            get
            {
                return (_currentErrors.Where(c => c.Value.Count > 0).Count() > 0);
            }
        }

        void FireErrorsChanged(string property)
        {
            if (ErrorsChanged != null)
            {
                ErrorsChanged(this, new DataErrorsChangedEventArgs(property));
            }
        }

        public void ClearErrorFromProperty(string property)
        {
            MakeOrCreatePropertyErrorList(property);

            _currentErrors[property].Clear();
            FireErrorsChanged(property);
        }

        public void AddErrorForProperty(string property, string error)
        {
            MakeOrCreatePropertyErrorList(property);
            _currentErrors[property].Add(error);
            FireErrorsChanged(property);
        }

        void MakeOrCreatePropertyErrorList(string propertyName)
        {
            if (!_currentErrors.ContainsKey(propertyName))
            {
                _currentErrors[propertyName] = new List<string>();
            }
        }


    }
}

用户控件 XAML：

<UserControl x:Class="SilverlightApplication1.TestUserControl"
    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"
    mc:Ignorable="d"
    d:DesignHeight="30" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <Button Content="..." Grid.Column="1" Padding="10,0" />
        <TextBox Text="{Binding Id, Mode=TwoWay}" />
    </Grid>
</UserControl>

用户控制 CS：

using System.Windows.Controls;

namespace SilverlightApplication1
{
    using System.ComponentModel;
    using System.Windows;

    public partial class TestUserControl : UserControl, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        public TestUserControl()
        {
            InitializeComponent();
            LayoutRoot.DataContext = this;
        }


        public string Id
        {
            get { return (string)base.GetValue(IdProperty); }
            set
            {
                base.SetValue(IdProperty, value);
                this.OnPropertyChanged("Id");
            }
        }

        public static DependencyProperty IdProperty =
            DependencyProperty.Register(
            "Id",
            typeof(string),
            typeof(TestUserControl),
            new PropertyMetadata(OnIdChanged));

        private static void OnIdChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (DesignerProperties.IsInDesignTool) return;

            var lookup = d as TestUserControl;
            lookup.OnPropertyChanged("Id");
        }

        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

    }
}

score 3 · Accepted Answer

为了使您的示例工作，您应该从文件中删除所有代码TestUserControl.xaml.cs并修复绑定。像这样：

<Button Content="..." Grid.Column="1" Padding="10,0" />
<TextBox Text="{Binding FirstValue, Mode=TwoWay, NotifyOnValidationError=True, ValidatesOnNotifyDataErrors=True}" />

后面是空代码：

public partial class TestUserControl : UserControl
{
    public TestUserControl()
    {
        InitializeComponent();
    }
}

接下来，你的另一个问题

在所有 3 个框（一个矩形）周围显示红色边框

它可以通过绑定到HasError属性来实现。根据您的代码，它看起来像这样：

<Grid x:Name="LayoutRoot" Background="White">
   <!-- ... -->
   <Border BorderBrush="Red" BorderThickness="1" 
            Grid.ColumnSpan="2" IsHitTestVisible="False"
            Visibility="{Binding HasErrors, Converter={StaticResource BooleanToVisibilityConverter}}" />

我添加了当属性设置为 trueBorder时可见的红色元素。HasError但是你应该OnPropertyChanged("HasError")在你的代码中调用某个地方。

另一种方式：创建自定义控件而不是UserControl。我已经发布了过多的描述如何在自定义控件中实现验证作为这个关于验证的问题的答案。

我可以给出更具体的答案，但是您应该通过将视图模型与视图分开来修复帖子中的代码，因为现在很难根据当前代码实现某些东西。查看我关于使用 INotifyDataErrorInfo 实现验证的帖子：WPF 和 Silverlight Validation。

或者你可以直接下载我的验证类。

之后代码会简单得多，我将能够帮助您解决更复杂的问题。

score 0 · Accepted Answer

改变

<TextBox Text="{Binding Id, Mode=TwoWay}" />

至

<TextBox Text="{Binding Id, Mode=TwoWay, NotifyOnValidationError=True, ValidatesOnDataErrors=True}" />

c# - 如何强制验证在 UserControl 上显示

2 回答 2

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