如何在C#中使用Regexp替换<；img>；带有它的HTML标记'；指定字符串中的s ALT参数

我有一个字符串，其中包含许多与此结构完全相同的HTML标记：

Hello <img src="./images/foo.gif" alt="bar"> World!
<img src="./images/foo2.gif" alt="bar2">

我使用C#和.NET Framework

使用，我设计了以下表达式：

<img src="[^"]*" alt="([^"]*)">

这显然需要生成的标记与您的示例非常精确地匹配，因此生成标记的内容中的任何更改都会导致此中断。出于这个原因，我建议你考虑使用一些代替ReGEX的方法来解决这个问题。 下面是Expresso通过大量使用示例生成的代码

//  using System.Text.RegularExpressions;

/// <summary>
///  Regular expression built for C# on: Mon, Nov 22, 2010, 03:51:18 PM
///  Using Expresso Version: 3.0.2766, http://www.ultrapico.com
///  
///  A description of the regular expression:
///  
///  <img src="
///      <img
///      Space
///      src="
///  Any character that is NOT in this class: ["], any number of repetitions
///  " alt="
///      "
///      Space
///      alt="
///  [1]: A numbered capture group. [[^"]*]
///      Any character that is NOT in this class: ["], any number of repetitions
///  ">
///      ">
///  
///
/// </summary>
public static Regex regex = new Regex(
      "<img src=\"[^\"]*\" alt=\"([^\"]*)\">",
      RegexOptions.Compiled
    );


// This is the replacement string
public static string regexReplace = "$1";


//// Replace the matched text in the InputText using the replacement pattern
// string result = regex.Replace(InputText,regexReplace);

//// Split the InputText wherever the regex matches
// string[] results = regex.Split(InputText);

//// Capture the first Match, if any, in the InputText
// Match m = regex.Match(InputText);

//// Capture all Matches in the InputText
// MatchCollection ms = regex.Matches(InputText);

//// Test to see if there is a match in the InputText
// bool IsMatch = regex.IsMatch(InputText);

//// Get the names of all the named and numbered capture groups
// string[] GroupNames = regex.GetGroupNames();

//// Get the numbers of all the named and numbered capture groups
// int[] GroupNumbers = regex.GetGroupNumbers();

//使用System.Text.RegularExpressions；
/// 
///为C#on构建的正则表达式：2010年11月22日星期一下午3:51:18
///使用Expresso版本：3.0.2766，http://www.ultrapico.com
///  
///正则表达式的说明：
///  
///  
///      ">
///  
///
/// 
公共静态正则表达式Regex=新正则表达式(
"",
RegexOptions.Compiled
);
//这是替换字符串
公共静态字符串regexReplace=“$1”；
////使用替换模式替换InputText中匹配的文本
//字符串结果=regex.Replace（InputText，regexReplace）；
////在正则表达式匹配的位置拆分InputText
//string[]results=regex.Split（InputText）；
////捕获InputText中的第一个匹配项（如果有）
//匹配m=正则表达式匹配（InputText）；
////捕获InputText中的所有匹配项
//MatchCollection ms=regex.Matches（InputText）；
////测试以查看InputText中是否存在匹配项
//bool IsMatch=regex.IsMatch（InputText）；
////获取所有命名和编号的捕获组的名称
//字符串[]GroupNames=regex.GetGroupNames（）；
////获取所有命名和编号的捕获组的编号
//int[]GroupNumbers=regex.GetGroupNumbers（）；

不仅感谢您提供的解决方案，还感谢您提供了一个可以在将来省去麻烦的好工具

//  using System.Text.RegularExpressions;

/// <summary>
///  Regular expression built for C# on: Mon, Nov 22, 2010, 03:51:18 PM
///  Using Expresso Version: 3.0.2766, http://www.ultrapico.com
///  
///  A description of the regular expression:
///  
///  <img src="
///      <img
///      Space
///      src="
///  Any character that is NOT in this class: ["], any number of repetitions
///  " alt="
///      "
///      Space
///      alt="
///  [1]: A numbered capture group. [[^"]*]
///      Any character that is NOT in this class: ["], any number of repetitions
///  ">
///      ">
///  
///
/// </summary>
public static Regex regex = new Regex(
      "<img src=\"[^\"]*\" alt=\"([^\"]*)\">",
      RegexOptions.Compiled
    );


// This is the replacement string
public static string regexReplace = "$1";


//// Replace the matched text in the InputText using the replacement pattern
// string result = regex.Replace(InputText,regexReplace);

//// Split the InputText wherever the regex matches
// string[] results = regex.Split(InputText);

//// Capture the first Match, if any, in the InputText
// Match m = regex.Match(InputText);

//// Capture all Matches in the InputText
// MatchCollection ms = regex.Matches(InputText);

//// Test to see if there is a match in the InputText
// bool IsMatch = regex.IsMatch(InputText);

//// Get the names of all the named and numbered capture groups
// string[] GroupNames = regex.GetGroupNames();

//// Get the numbers of all the named and numbered capture groups
// int[] GroupNumbers = regex.GetGroupNumbers();