WPF字符串长度转换器

Question

我正在使用转换器检查字符串长度是否大于0.如果它更大我会返回true,否则为false.

一切都很好.但我想知道这是否是转换器的正确方法？

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool error = false;
        if (value != null)
        {
            if (value.ToString().Length > 0)
            {
                error = true;
            }
            else
            {
                error = false;
            }
        }
        return error;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new InvalidOperationException("IsNullConverter can only be used OneWay.");
    }

Answer 1

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
    string str = value as string;
    return !String.IsNullOrEmpty(str);
}