如何通过C#修改txt文件的某些部分

string filePath = "path/to/your/file.txt";
string fileContent = File.ReadAllText(filePath);

string newText = "Your new text";
string oldText = "Text to be replaced";
fileContent = fileContent.Replace(oldText, newText);

string newText1 = "New text 1";
string oldText1 = "Text to be replaced 1";
string newText2 = "New text 2";
string oldText2 = "Text to be replaced 2";

fileContent = fileContent.Replace(oldText1, newText1).Replace(oldText2, newText2);

File.WriteAllText(filePath, fileContent);