C＃：与XML.load的close方法（文件） [英] C# : the close method of Xml.Load(file)

问题描述

我写了使用的XmlDocument 对象加载XML文档，这样才能算它的节点一些代码。这里是方法：

I have written some code that loads an XML document using an XmlDocument object so as to count it's nodes. Here is the method:

XmlDocument xml = new XmlDocument();
xml.Load(textBox1.Text);
XmlNodeList nodes = xml.SelectNodes("//File");
foreach (XmlNode node in nodes)
{
    number_of_childs++;
}

这是我现在面临的问题是，导入大量文件时，它需要像RAM 700MB。如果我再尝试做对文件中的一些操作，甚至可以从中读取在的ListView 来显示其数据，应用程序需要像2GB的RAM。所以，我想知道，有没有关闭的XmlDocument 并释放其内存，释放内存的方法。它就像它忘记从内存中删除的内容。

The problem that I am facing is, when importing a large file, it takes like 700MB of RAM. If I then try to do some operation on the file, or even read from it to display its data in a ListView, the application takes like 2GB of RAM. So, I was wondering, is there a method that closes the XmlDocument and frees its memory, releasing the RAM. It is like it's forgetting to remove its content from memory.

推荐答案

没有。在的XmlDocument 类未实现的IDisposable ，所以没有办法，迫使它随心所欲地释放它的资源。如果你真的需要立即释放由的XmlDocument 使用的内存，这样做，是做以下的唯一方法：

No. The XmlDocument class does not implement IDisposable, so there is no way to force it to release it's resources at will. If you really need to immediately free the memory used by XmlDocument, the only way to do that would be to do the following:

nodes = null;
xml = null;
GC.Collect();

垃圾收集器工作在一个单独的线程，因此它可能仍不会立即发生。要强制垃圾收集同步发生，你的代码继续执行之前，你还必须调用 WaitForPendingFinalizers ，因为这样的：

nodes = null;
xml = null;
GC.Collect();
GC.WaitForPendingFinalizers();

的XmlDocument 总是加载整个文档到内存立刻。如果你只是想通过节点的文档作为流中的迭代，每次只装了一下，那就是的XmlReader 类是什么。但是，你失去了很多功能的方式。举例来说，有没有办法通过XPath的选择节点，如你在哪里在你的例子做。随着的XmlReader ，你必须写你自己的逻辑来确定你在哪里，是否符合你在找什么在文档中。

XmlDocument always loads the entire document into memory at once. If you simply want to iterate through the nodes in the document as a stream, only loading a bit at a time, that is what the XmlReader class is for. However, you lose a lot of functionality that way. For instance, there is no way to select nodes via XPath, as you where doing in your example. With XmlReader, you have to write your own logic to determine where in the document you are and whether that matches what you are looking for.

这篇关于C＃：与XML.load的close方法（文件）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！