c＃替换文件中的字符串
[英]c# replace string within file
问题描述
String.Replace doesn't seem to work properly when replacing a portion of an HTML file's content. 
替换HTML文件内容的一部分时，String.Replace似乎无法正常工作。 For example, String.Replace replaces </body></html> with blah blah blah </body></html> html> - notice the second HTML closing tag is not properly closed and therefore shows up when the page is rendered in the browser by the user. 例如，String.Replace用blah blah blah </body></html> html>替换</body></html> blah blah blah </body></html> html> - 注意第二个HTML结束标记未正确关闭，因此在页面呈现时显示用户的浏览器。
Anyone know why it's not working as intended? 任何人都知道它为什么不按预期工作？
StreamReader sr = fi.OpenText;
String fileContents = sr.ReadToEnd();
sr.close();
fileContents = fileContents.Replace("<body>", "<body onload='jsFx();' />");
fileContents = fileContents.Replace("</body>","blah blah blah </body>");
StreamWriter sw = new StreamWriter(fi.OpenWrite());
sw.WriteLine(contents);
sw.close();
2 个解决方案
解决方案1
56 2010-12-02 21:06:15
I might rewrite your bit of code like this: 我可能会像这样重写你的代码：
var fileContents = System.IO.File.ReadAllText(@"C:\File.html");
fileContents = fileContents.Replace("<body>", "<body onload='jsFx();' />");
fileContents = fileContents.Replace("</body>","blah blah blah </body>");
System.IO.File.WriteAllText(@"C:\File.html", fileContents);
I should note that this solution is fine for files of reasonable size. 我应该注意，这个解决方案适用于合理大小的文件。 Depending on hardware, any thing under a few tens of MB. 取决于硬件，任何低于几十MB的东西。 It loads the entire contents into memory. 它将整个内容加载到内存中。 If you have a really large file you may need to stream it through a few hundred KB at a time to prevent an OutOfMemoryException. 如果你有一个非常大的文件，你可能需要一次流几百KB来防止OutOfMemoryException。 That makes things a bit more complicated, since you'd need to also check the break between each chunk to see if split your search string. 这使得事情变得更复杂，因为您还需要检查每个块之间的中断以查看是否拆分了搜索字符串。
解决方案2
14 2010-12-02 21:04:04
There's nothing wrong with string.Replace here. string.Replace在这里没什么问题。
What is wrong is that you're overwriting the file but not truncating it... so if you changed your writing code to just 什么是错的，你覆盖文件，但不截断它......所以如果你改变了你写代码，只是
sw.WriteLine("Start");
you'd see "Start" and then the rest of the file. 你会看到“开始”，然后是文件的其余部分。
I would recommend that you use File.ReadAllText and File.WriteAllText instead (take the path from the FileInfo ). 我建议您使用File.ReadAllText和File.WriteAllText （从FileInfo获取路径）。 That way: 那样：
- It will completely replace the file, instead of just overwriting 它将完全替换文件，而不是仅覆盖
- You don't need to worry about closing the reader/writer/stream properly (which you're not doing now - if an exception occurs, you're leaving the reader or writer open) 您无需担心正确关闭读取器/写入器/流（您现在没有这样做 - 如果发生异常，您将使读取器或写入器保持打开状态）
If you really want to use the FileInfo methods, use FileInfo.Open(FileMode.Create) which will truncate the file. 如果您确实想使用FileInfo方法，请使用FileInfo.Open(FileMode.Create)来截断该文件。
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