反转格式字符串并确定正确结果

Question

我必须反转格式字符串以提取 "Email" 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;

我的期望是让值 "Email" 变为 "extractedField" 并且 "isRequired" 变为 true

更新：对不起，如果我在解释自己时过于笼统。为了更好地阐明我的意图，我创建了一个 fiddle https://dotnetfiddle.net/cjPAo1

Answer 1

我相信我理解您的 query.You 想要检查当前消息与哪个 "expression" 匹配，并根据它，将适当的标志设置为 true。同时检索有问题的 'field'。

实现它的一种方法是

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}");

其中 ToRegex 定义为

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);
}

Demo Code

以上代码使用 Regex 找到合适的匹配项。

示例输出

extractedField=Age,1,99,
isRequired=False,
isDate=False

更新

根据您的评论，要支持多个词，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);
}

Answer 2

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;
        }
    }

Answer 3

使用Regex.Match函数ExtractFieldAndDeterminateType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;
}

OP测试数据输出：

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： 已将示例代码添加到 fiddle Link to fiddle

反转格式字符串并确定正确结果

Reverse format string and determinate correct result

c#

formatting

reverse

format-string

更新