C# 反向格式化字符串并确定正确的结果

我必须反转格式字符串以提取“电子邮件”，并确定正确的布尔结果

string input = "The Email field is required.";

string required = "The {0} field is required.";
string date = "The {0} field is not a valid date.";

bool isRequired = false;
bool isDate = false;

string extractedField;

我的期望是将“Email”值设置为“extractedField”，将“isRequired”值设置为true

更新：

---

对不起，我解释得太笼统了。为了更好地阐明我的意图，我创建了一个fiddle

我相信我理解了您的查询。您希望检查当前消息与哪个“表达式”匹配，并根据它将相应的标志设置为true。还要检索有问题的“字段”

实现这一目标的一个方法是

更新

根据您的评论，已更新代码以支持多个字段

string input = "Age should be between 1 and 99.";
string required = "The {0} field is required.";
string date = "The {0} field is not a valid date.";
string range = "{0} should be between {1} and {2}.";

bool isRequired = false;
bool isDate = false;
bool isRange = false;
string extractedField;


var possibilities = new []
                    {
                        new KeyValuePair<string,Action>(ToRegex(required), ()=>((Action)(() => { isRequired = true;}))()),
                        new KeyValuePair<string,Action>(ToRegex(date), ()=>((Action)(() => { isDate = true;}))()),
                        new KeyValuePair<string,Action>(ToRegex(range), ()=>((Action)(() => { isRange = true;}))())
                    };
var result = possibilities
             .Where(x=>Regex.Match(input,x.Key).Success)
             .Select(x=> new KeyValuePair<IEnumerable<string>,Action>( 
                                            Regex.Match(input,x.Key).Groups.Cast<Group>().Where(c=>c.Name.StartsWith("Field")).Select(c=>c.Value),
                                            x.Value)).First();


var fields = result.Key;
result.Value();
Console.WriteLine($"{nameof(extractedField)}={string.Join(",",fields)},{Environment.NewLine}{nameof(isRequired)}={isRequired},{Environment.NewLine}{nameof(isDate)}={isDate}");

更新 根据您的评论，要支持多个单词，您可以使用以下内容

public string ToRegex(string value)
{
    var result = new List<string>();
    foreach(var item in value.Split(' '))
    {
        if(Regex.Match(item,@"{(?<Value>\d*)}").Success)
        {
            var match = Regex.Match(item,@"{(?<Value>\d*)}");

            result.Add(Regex.Replace(item,@"{(?<Value>\d*)}",$"(?<Field{match.Groups["Value"].Value}>[\\S ]*)"));
            continue;
        }
        result.Add(item);
    };
    return string.Join(" ",result);
}

公共字符串ToRegex（字符串值）
{
var result=新列表（）；
foreach（价值中的var项目分割（“”））
{
if（Regex.Match（项，@“{（？\d*）}”）.Success）
{
var match=Regex.match（项，@“{（？\d*）}”）；
结果.Add（Regex.Replace（item，@“{（？\d*）}”，$”（？[\\S]*）”）；
继续；
}
结果.添加（项目）；
};
返回字符串。Join（“，result）；
}

尝试以下操作：

    class Program
    {
        static void Main(string[] args)
        {
            string[] inputs = {
                                  "The Email field is required.",
                                  "The Username field is required.",
                                  "The InsertDate field is not a valid date.",
                                  "Age should be between 1 and 99."
                              };
            Type type;
            foreach (string input in inputs)
            {
                string word = ExtractFieldAndDeterminateType(input, out type);
                Console.WriteLine(word);
            }
            Console.ReadLine();
        }
        public static string ExtractFieldAndDeterminateType(string input, out Type type)
        {
            string[] words = input.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

            int index = 0;
            if (words[0] == "The") index = 1;

            string word = words[index];

            switch (word)
            {
                case "Email" :
                    type = typeof(string);
                    break;

                case "Username":
                    type = typeof(string);
                    break;

                case "InsertDate":
                    type = typeof(DateTime);
                    break;

                case "Age":
                    type = typeof(int);
                    break;

                default:
                    type = (Type)Type.Missing;
                    break;
            }

            return word;
        }
    }

---

使用

Regex.Match

函数

extractField和determinateType

可以写成：

public static string ExtractFieldAndDeterminateType(string input, out Type type)
{
    var extractedField = "";
    string required = "The (.*) field is (.*).";
    //string date = "The (.*) field is not a (.*)."; => Not needed
    string range = "(.*)(?= should be between)";
    type = Type.Unknown;

    var match = Regex.Match(input, required);
    if (match.Success)
    {
        extractedField = match.Groups[1].Value;
        switch (match.Groups[2].Value)
        {
            case "required":
                type = Type.Error;
                break;
            case "not a valid date":
                type = Type.Date;
                break;
        }
    }
    else if ((match = Regex.Match(input, range)).Success)
    {
        extractedField = match.Groups[1].Value;
        type = Type.Range;
    }
    else
    {
        //Nothing 
    }
    return extractedField;
}

输出OP的测试数据：

Field is: Email and Type is: Error
Field is: Username and Type is: Error
Field is: InsertDate and Type is: Date
Field is: Age and Type is: Range

---

已编辑：添加了用于小提琴的示例代码

提供更好的输入字符串示例。你想得到字符串的第二个单词吗？在空格上使用字符串拆分并获取数组中的第二项。我用一个例子更新了帖子，以更好地解释我的意图。是的，这就是我要找的！非常感谢。您认为可以提取多个字段，比如这里的“范围”示例吗？我不想返回所有的结果（第一个就足够了），只想在extractedFields@Sauron请检查更新的代码。我还更新了代码以使用正则表达式而不是拆分字比较方法，并且它还支持多个字段。请检查点小提琴LIKI可以考虑这个答案是正确的，因为它是第一个有效的解决方案，描述得很好，适合于每一个使用。嗨，Anu Viswan，我注意到如果我用“新密码字段是必需的”来改变输入，它就不起作用了。看起来ToRegex方法只接受单个单词。非常感谢。@Sauron我已经更新了答案以支持该场景，请验证

public static string ExtractFieldAndDeterminateType(string input, out Type type)
{
    var extractedField = "";
    string required = "The (.*) field is (.*).";
    //string date = "The (.*) field is not a (.*)."; => Not needed
    string range = "(.*)(?= should be between)";
    type = Type.Unknown;

    var match = Regex.Match(input, required);
    if (match.Success)
    {
        extractedField = match.Groups[1].Value;
        switch (match.Groups[2].Value)
        {
            case "required":
                type = Type.Error;
                break;
            case "not a valid date":
                type = Type.Date;
                break;
        }
    }
    else if ((match = Regex.Match(input, range)).Success)
    {
        extractedField = match.Groups[1].Value;
        type = Type.Range;
    }
    else
    {
        //Nothing 
    }
    return extractedField;
}

Field is: Email and Type is: Error
Field is: Username and Type is: Error
Field is: InsertDate and Type is: Date
Field is: Age and Type is: Range