WPF-使用Int32.Parse后出错

在

ComboBoxNotEmptyValidationRule

class I中使用

Int32.Parse

后，出现错误：

Input string was not in a correct format.

当我添加到XAML时：

<local:ComboBoxNotEmptyValidationRule x:Name="Number" ValidatesOnTargetUpdated="True"/>

---

您可以使用

int32.TryParse

class ComboBoxNotEmptyValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        int str;
        if (Int32.TryParse(value as string, out str))
        {
            if (str > 0)
                return ValidationResult.ValidResult;
        }
        return new ValidationResult(false, "please fill required field");
    }
}

或者，您可以捕获

FormatException

，并返回错误的验证结果

class ComboBoxNotEmptyValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        int str = -1;
        try
        {
            str = Int32.Parse(value as string);
            if (str > 0)
            {
                if (str > 0)
                    return ValidationResult.ValidResult;
            }
            return new ValidationResult(false, "please fill required field");
        }
        catch (FormatException)
        {
            return new ValidationResult(false, "please fill required field");
        }
    }
}

---

你能展示更多的代码吗？我们不知道什么是

ComboBoxNotEmptyValidationRule

等等@Jeff Meadows我添加了这个类。你确定值的类型是string吗？价值的内容是什么？

class ComboBoxNotEmptyValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        int str = -1;
        try
        {
            str = Int32.Parse(value as string);
            if (str > 0)
            {
                if (str > 0)
                    return ValidationResult.ValidResult;
            }
            return new ValidationResult(false, "please fill required field");
        }
        catch (FormatException)
        {
            return new ValidationResult(false, "please fill required field");
        }
    }
}