如何在单个 foreach 中匹配两个字符串？

Question

我正在使用正则表达式来匹配文件中的字符，但我想匹配该文件中的 2 个不同的字符串，但它们不止一次出现，这就是我使用循环的原因。 我可以匹配单个字符串，但不能匹配 2 个字符串。

Regex celcius = new Regex(@"""temp"":\d*\.?\d{1,3}"); 
foreach (Match match in celcius.Matches(htmlcode))
{ 
    Regex date = new Regex(@"\d{4}-\d{2}-\d{2}");
    foreach (Match match1 in date.Matches(htmlcode))
    {
        string date1 = Convert.ToString(match1.Value);
        string temperature = Convert.ToString(match.Value);
        Console.Write(temperature + "\t" + date1);
    }
}

html代码：

{"temp":287.05,"temp_min":286.932,"temp_max":287.05,"pressure":1019.04,"sea_level":1019.04,"grnd_level":1001.11,"humidity":89,"temp_kf":0.12},"weather":[{"id":804,"main":"Clouds","description":"overcast
clouds","icon":"04n"}],"clouds":{"all":100},"wind":{"speed":0.71,"deg":205.913},"sys":{"pod":"n"},"dt_txt":"2019-09-22
21:00:00"},{"dt":1569196800,"main":{"temp":286.22,"temp_min":286.14,"temp_max":286.22,"pressure":1019.27,"sea_level":1019.27,"grnd_level":1001.49,"humidity":90,"temp_kf":0.08},"weather":[{"id":804,"main":"Clouds","description":"overcast
clouds","icon":"04n"}],"clouds":{"all":99},"wind":{"speed":0.19,"deg":31.065},"sys":{"pod":"n"},"dt_txt":"2019-09-23
00:00:00"},{"dt":1569207600,"main":{"temp":286.04,"temp_min":286,"temp_max":286.04,"pressure":1019.38,"sea_level":1019.38,"grnd_level":1001.03,"humidity":89,"temp_kf":0.04},"weather":

Answer 1

您可以使用具有两个捕获组的单个正则表达式模式来获取温度和日期。 该模式可能如下所示：

("temp":\d*\.?\d{1,3}).*?(\d{4}-\d{2}-\d{2})

正则表达式演示。

C# 示例：

string htmlcode = // ...
var matches = Regex.Matches(htmlcode, @"(""temp"":\d*\.?\d{1,3}).*?(\d{4}-\d{2}-\d{2})");
foreach (Match m in matches)
{
    Console.WriteLine(m.Groups[1].Value + "\t" + m.Groups[2].Value);
}

Output：

"temp":287.05   2019-09-22
"temp":286.22   2019-09-23

在线尝试。

Answer 2

我认为您没有 HTML。 我认为您有一个名为 JSON（JavaScript Object 通知）的东西的集合，这是一种有效传递数据的方法。

所以，这是您的“HTML”对象之一。

{
    "temp":287.05,
    "temp_min":286.932,
    "temp_max":287.05,
    "pressure":1019.04,
    "sea_level":1019.04,
    "grnd_level":1001.11,
    "humidity":89,
    "temp_kf":0.12},
    "weather":[{
        "id":804,
        "main":"Clouds",
        "description":"overcast clouds",
        "icon":"04n"
    }],
    "clouds":{
        "all":100
    },
    "wind":{
        "speed":0.71,"deg":205.913
    },
    "sys":{
        "pod":"n"
    },
    "dt_txt":"2019-09-22 21:00:00"
}

因此，我建议使用 C# web 助手转换行并直接解析对象。

//include this library
using System.Web.Helpers;

//parse your htmlcode using this loop
foreach(var line in htmlcode)
{
    dynamic data = JSON.decode(line);
    string temperature = (string)data["temp"];
    string date = Convert.ToDateTime(data["dt_txt"]).ToString("yyyy-MM-dd");
    Console.WriteLine($"temperature: {temperature} date: {date}"");
}