使用 .NET Regex.Replace() 多次替换表达式 [重复]

Question

我似乎找不到这个问题的匹配项，所以如果它是重复的，我提前道歉。

给定模板：<<FirstName>> << FirstName >>

我想使用应该匹配两者的单个正则表达式替换'<<>>' 之间的两个字符串。

以下代码似乎没有按我预期的方式工作：

[Test]
public void ShouldReplaceMultiple()
{
  var pattern = "<<.*FirstName.*>>";
  var template = "<<FirstName>> <<FirstName>>";
  var replaceWith = "FOO";

  var regex = new Regex(pattern); 

  Assert.AreEqual("FOO FOO", regex.Replace(template, replaceWith));
}

测试的输出如下：

Expected string length 7 but was 3. Strings differ at index 3.
  Expected: "FOO FOO"
  But was:  "FOO"
  --------------^

我不明白为什么两个字符串都不会被替换？

Answer 1

使用.*?使其不贪婪

var pattern = "<<.*?FirstName.*?>>";
var template = "<<FirstName>> <<FirstName>>";
var replaceWith = "FOO";

var regex = new Regex(pattern); 

Console.WriteLine(regex.Replace(template, replaceWith));

Ideone Demo

如果你只想处理<<>>之间的spaces，那么这就足够了

<<\s*?FirstName\s*?>>

Answer 2

string pattern = @"<<(?<=<<)\s*FirstName\s*(?=>>)>>";
var template = "<<FirstName>> <<FirstName>>";
var replaceWith = "FOO";

var regex = new Regex(pattern); 

Assert.AreEqual("FOO FOO", regex.Replace(template, replaceWith));