Question

您好我需要在我的应用程序中验证一些文本框。我决定使用验证规则 “DataErrorValidationRule”。这就是为什么在我的课上我实现了IDataErrorInfo接口并编写了aproperiate函数。在我的xaml代码中，我将绑定和验证规则添加到文本框

 <TextBox x:Name="txtName" Grid.Column="3" Grid.Row="1"  TextAlignment="Center" >
                        <TextBox.Text>
                            <Binding Path="Name" >
                                <Binding.ValidationRules>
                                    <DataErrorValidationRule></DataErrorValidationRule>
                                </Binding.ValidationRules>
                            </Binding>
                        </TextBox.Text>
                    </TextBox>

验证此文本框是否正常 - 我的意思是如果数据错误，则会在文本框中显示红框。然而，我需要做的是在该文本框上显示工具提示，但更重要的是，如果任何文本框有错误的数据，我必须禁用“运行”按钮。什么是最好的方法？

EDIT 第一个问题解决了，但我有另一个问题。我需要使用MultiBindings来验证我的Button。所以我做了那样的

 <Button x:Name="btnArrange"  Grid.Column="0"  Content="Rozmieść" Click="btnArrange_Click" >
                <Button.Style>
                    <Style TargetType="Button">
                        <Style.Triggers>
                            <DataTrigger Value="False">
                                <DataTrigger.Binding>
                                    <MultiBinding Converter="{StaticResource BindingConverter}">
                                        <Binding ElementName="txtName" Path="Validation.HasError" />
                                        <Binding ElementName="txtSurname" Path="Validation.HasError"/>
                                        <Binding ElementName="txtAddress" Path="Validation.HasError"/>

                                    </MultiBinding>
                                </DataTrigger.Binding>
                                <Setter Property="IsEnabled" Value="False"/>

                            </DataTrigger>
                        </Style.Triggers>
                    </Style>        
                </Button.Style>

        </Button>

我的转换器看起来像那样

 public  class Converters : IMultiValueConverter
{

    #region IMultiValueConverter Members

    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if(values !=null && values.Length > 0)
        {


            if (values.Cast<type>().Count(val => val) > 0)
                return false;
            return true;
        }
        return false;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        return null;
    }

    #endregion
}

但是我在这个转换器中遇到invalidCastException。在这种情况下，什么是适当的演员？我觉得好像HasError是一个bool类型所以我应该转向bool。

Answer 1

要在工具提示中显示错误消息，请将其放入Application.Resources：

<Style x:Key="textBoxInError" TargetType="{x:Type TextBox}">
  <Style.Triggers>
    <Trigger Property="Validation.HasError" Value="true">
      <Setter Property="ToolTip"
        Value="{Binding RelativeSource={x:Static RelativeSource.Self},
                        Path=(Validation.Errors)[0].ErrorContent}"/>
    </Trigger>
  </Style.Triggers>
</Style>

（来自http://msdn.microsoft.com/en-us/library/system.windows.controls.validation.errortemplate.aspx的例子）

要启用/禁用按钮，您可以使用

行

<Button x:Name="btnOK" Content="OK" IsDefault="True" Click="btnOK_Click">
  <Button.Style>
    <Style TargetType="{x:Type Button}">
      <Setter Property="IsEnabled" Value="false" />
      <Style.Triggers>
        <MultiDataTrigger>
          <MultiDataTrigger.Conditions>
            <Condition Binding="{Binding ElementName=txt1, Path=(Validation.HasError)}" Value="false" />
            <Condition Binding="{Binding ElementName=txt2, Path=(Validation.HasError)}" Value="false" />
          </MultiDataTrigger.Conditions>
          <Setter Property="IsEnabled" Value="true" />
        </MultiDataTrigger>
      </Style.Triggers>
    </Style>
  </Button.Style>
</Button>

或者您可以实现ICommand并使用命令绑定。

修改

这是一个完整的例子。它显示一个带有两个TextBox的窗口。当且仅当两个TextBox都非空时，才启用Button。创建一个名为ValidationDemo的项目，并将以下文件放入其中：

<强> MainWindow.xaml：

<Window x:Class="ValidationDemo.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="146" Width="223"> <Window.Resources> <Style TargetType="{x:Type TextBox}"> <Style.Triggers> <Trigger Property="Validation.HasError" Value="true"> <Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/> </Trigger> </Style.Triggers> </Style> </Window.Resources> <Grid> <Label Content="A" Height="28" HorizontalAlignment="Left" Margin="46,7,0,0" Name="label1" VerticalAlignment="Top" /> <TextBox Name="txtA" Text="{Binding Path=TextA, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" Height="23" HorizontalAlignment="Left" Margin="69,12,0,0" VerticalAlignment="Top" Width="120" /> <Label Content="B" Height="28" HorizontalAlignment="Left" Margin="46,39,0,0" Name="label2" VerticalAlignment="Top" /> <TextBox Name="txtB" Text="{Binding Path=TextB, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" Height="23" HorizontalAlignment="Left" Margin="69,41,0,0" VerticalAlignment="Top" Width="120" /> <Button Name="btnOk" Content="OK" Height="23" HorizontalAlignment="Left" Margin="114,70,0,0" VerticalAlignment="Top" Width="75" Click="btnOk_Click"> <Button.Style> <Style TargetType="{x:Type Button}"> <Setter Property="IsEnabled" Value="false" /> <Style.Triggers> <MultiDataTrigger> <MultiDataTrigger.Conditions> <Condition Binding="{Binding ElementName=txtA, Path=(Validation.HasError)}" Value="false" /> <Condition Binding="{Binding ElementName=txtB, Path=(Validation.HasError)}" Value="false" /> </MultiDataTrigger.Conditions> <Setter Property="IsEnabled" Value="true" /> </MultiDataTrigger> </Style.Triggers> </Style> </Button.Style> </Button> </Grid> </Window>

<强> MainWindow.xaml.cs：

using System.Windows; namespace ValidationDemo { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { private Model model = new Model(); public MainWindow() { InitializeComponent(); this.DataContext = this.model; } private void btnOk_Click(object sender, RoutedEventArgs e) { Application.Current.Shutdown(); } } }

<强> Model.cs：

using System; using System.ComponentModel; namespace ValidationDemo { public class Model : INotifyPropertyChanged, IDataErrorInfo { public event PropertyChangedEventHandler PropertyChanged; private string textA = string.Empty; public string TextA { get { return this.textA; } set { if (this.textA != value) { this.textA = value; this.OnPropertyChanged("TextA"); } } } private string textB = string.Empty; public string TextB { get { return this.textB; } set { if (this.textB != value) { this.textB = value; this.OnPropertyChanged("TextB"); } } } public string Error { get { throw new NotImplementedException(); } } public string this[string columnName] { get { string result = string.Empty; switch (columnName) { case "TextA": if (string.IsNullOrEmpty(this.textA)) { result = "'A' must not be empty"; } break; case "TextB": if (string.IsNullOrEmpty(this.textA)) { result = "'B' must not be empty"; } break; } return result; } } protected virtual void OnPropertyChanged(string propertyName) { if (this.PropertyChanged != null) { this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } }

Answer 2

<Window.Resources>
    <Style x:Key="ElementInError" TargetType="{x:Type FrameworkElement}">
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Setter Property="ToolTip"
                    Value="{Binding (Validation.Errors)[0].ErrorContent, RelativeSource={x:Static RelativeSource.Self}}"/>
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<!-- ... -->
<TextBox x:Name="txtName" Style="{StaticResource ElementInError}">
    <!-- ... -->        
</TextBox>
<!-- ... --> 
        <Button x:Name="OkButton" Content="Ok" Margin="5" Click="OkButton_Click">
            <Button.Style>
                <Style TargetType="Button">
                    <Style.Triggers>
                        <DataTrigger Binding="{Binding ElementName=txtName,Path=(Validation.HasError)}" Value="True">
                            <Setter Property="IsEnabled" Value="False" />
                        </DataTrigger>
                    </Style.Triggers>
                </Style>
            </Button.Style>
        </Button>

Answer 3

如果您创建验证摘要，则可以将“运行”按钮的IsEnabled属性绑定到其HasErrors属性。

当IsEnabled为假时，您需要使用中间属性或转换器，true为HasErrors。反之亦然。

wpf - 验证 - 如何显示工具提示并禁用“运行”按钮

3 个答案: