Question

我是wpf的新手，我尝试了很多教程，使用ValidationRule轻松验证，但没有什么可以帮助我，我很困惑！我的问题是实现我自己的项目我点击按钮时有一个主窗口显示一个要求输入数字的对话框，我需要对这个号码进行验证

这是对话框的XAML：

<Window x:Name="kInputWindow1" x:Class="FinalProject.kInputWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:FinalProject"
     Title="Input" SizeToContent="WidthAndHeight" WindowStartupLocation="CenterScreen"
    ContentRendered="Window_ContentRendered">
<Grid Margin="15">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="*" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>

    <Image Source="question.jpg" Width="32" Height="32" Grid.RowSpan="2" Margin="20,0" />

    <Label Name="lblQuestion" Grid.Column="1">Question:</Label>
    <TextBox Name="txtAnswer" MinWidth="250" Grid.ColumnSpan="2" Margin="71,26,0.6,0" Grid.RowSpan="2" PreviewTextInput="NumberValidationTextBox" 
             ToolTip="{Binding RelativeSource={RelativeSource Self},  Path=(Validation.Errors)[0].ErrorContent}">
        <TextBox.Text>
            <Binding Path="txtAnswer" UpdateSourceTrigger="PropertyChanged" 
                 ValidatesOnDataErrors="True" ValidatesOnExceptions="True">
                <Binding.ValidationRules>
                    <DataErrorValidationRule />
                </Binding.ValidationRules>
            </Binding>
        </TextBox.Text>
    </TextBox>

    <WrapPanel Grid.Row="2" Grid.ColumnSpan="2" HorizontalAlignment="Right" Margin="0,15,0,0">
        <Button IsDefault="True" Name="btnDialogOk" Click="btnDialogOk_Click" MinWidth="60" Margin="0,0,10,0">_Ok</Button>
        <Button IsCancel="True" MinWidth="60">_Cancel</Button>
    </WrapPanel>
</Grid>

这是代码：

public partial class kInputWindow : Window
{

    public kInputWindow(string question)
    {
        InitializeComponent();
        lblQuestion.Content = question;
    }

    private void btnDialogOk_Click(object sender, RoutedEventArgs e)
    {
        this.DialogResult = true;
    }

    private void Window_ContentRendered(object sender, EventArgs e)
    {
        txtAnswer.SelectAll();
        txtAnswer.Focus();
    }

    public string Answer
    {
        get { return txtAnswer.Text; }
    }

    private void NumberValidationTextBox(object sender, TextCompositionEventArgs e)
    {
        Regex regex = new Regex("[^0-9]+");
        e.Handled = regex.IsMatch(e.Text);
    }

}

public class CustomValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
    {
        if (string.IsNullOrEmpty(value.ToString()))
            return new ValidationResult(false, "No number was entered!");
        if (value.ToString().Contains(' '))
            return new ValidationResult(false, "No spaces allowed!");

        return ValidationResult.ValidResult;
    }
}

我真的不知道为了让它的工作缺少什么

Answer 1

您的代码中有2个错误： 1.您使用DataErrorValidationRule而不是您自己的CustomValidationRule。所以应该是这样的：

<Binding.ValidationRules>
  <local:CustomValidationRule/>
</Binding.ValidationRules>

2。您需要在“文本绑定”属性上具有正确的路径。现在你绑定了属性“txtAnswer”但是你的TextBox.DataContext中没有这样的属性（实际上你根本就没有DataContext）。使其工作的最小示例是将示例属性添加到Window并将Window设置为自身的DataContext：

public partial class kInputWindow  : Window
{
  public string ResultText { get; set; }

  public MainWindow()
  {
    InitializeComponent();
    this.DataContext = this;
   }

然后将TextBox绑定到此属性：

<Binding Path="ResultText" UpdateSourceTrigger="PropertyChanged" 
             ValidatesOnDataErrors="True" ValidatesOnExceptions="True">

需要帮助才能进行简单的文本框验证

1 个答案: