如何遍历物理文件夹并读取C＃中的叶文件

Question

I have a root node A which contains B which contains C which contains D which contains an XML file abc.xml So in D:\\ drive ,I have the following structure of directories A>>B>>C>>D. This path is dynamic. What is the best practice to read the file abc.xml in C# by iterating through the physical folders?

Answer 1

You could implement a recursive search algorithm that goes through all the folders and descends into the sub folders.

Pseudo Code:

public void GetXMLFilesRecursive(string currentFolder, List<string> results)
{
    // Enumerate all directories of currentFolder
    string[] folders = Directory.GetDirectories(currentFolder);
    foreach (string folder in folders)
        GetXMLFilesRecursive(folder, results));

    // Enumerate all XML files in this folder only if it has no other sub-folders (is a leaf)
    if (folders.Length == 0)
    {
        string[] xmlFiles = Directory.GetFiles(currentFolder, "*.xml");
        results.AddRange(xmlFiles);
    }
}

This method only returns XML files in the lowest folders of the hierarchy (ie folders that don't have sub folders). If you want all files you find along the way, comment out if (folders.Length == 0) . On the other hand, you could then also use Directory.GetFiles with SearchOption.AllDirectories .

---

Why I wrote a recursive algorithm: The OP asked how to find all XML files in the leaf directories. You can not do that using Directory.GetFiles with SearchOption.AllDirectories , but you then need to implement the above.

Answer 2

您可以使用Directory.GetFiles(d, "*.xml",SearchOption.AllDirectories)获取所有xml文件，以获取所需的内容。

Answer 3

You can search an entire tree for a file using Directory.GetFiles(path,searchPattern,SearchOption) or Directory.EnumerateFiles with SearchOption.AllDirectories , eg

var fullPaths=Directory.GetFiles(myPath,"abc.xml",SearchOption.AllDirectories)

You can also use the DirectoryInfo class to get full FileInfo instances instead of just the paths, with access to file properties and attributes:

var myDir=new DirectoryInfo(myPath);
var fileInfos=myDir.GetFiles("abc.xml",SearchOption.AllDirectories);

The difference between the GetFiles and EnumerateFiles methods is that the first returns an array with all the files found, blocking until it finds all of them. EnumerateFiles on the other hand returns results as it finds them, so you get to process the results much sooner.

What goes for GetFiles goes for the GetDirectories / EnumerateDirectories set of functions as well. The methods are available both from the Directory and DirectoryInfo class.

If you want to search for both directories and files, you can use GetFileSystemEntries / EnumerateFileSystemEntries to return both of them with a single call. The equivalent DirectoryInfo methods are GetFileSystemInfos / EnumerateFileSystemInfos

Answer 4

public List<string> getFiles(string path, string searchPattern, List<string> list)
{
    try
    {
        foreach (string folder in Directory.GetDirectories(path))
            getFiles(folder, searchPattern, list);
        list.AddRange(Directory.GetFiles(path, searchPattern));
    }
    catch (UnauthorizedAccessException)
    {
        //Do not have access to the file.
    }
    return list;
}

Call like this:

//Get all xml files in the D drive:
List<string> files = getFiles(@"d:\", "*.xml", new List<string>());