winrt如何使用C＃从设备获取文件列表

Question

I need get a list of all files in device (phone or PC) in my universal app. In wpf I did somesing like that:

class Collection {
    private StringCollection seachResults; 
    //find all mp3 files in local storage
    private void ScanDrives() {
        seachResults.Clear();
        string[] drives = Environment.GetLogicalDrives();
        foreach (string dr in drives) {
            DriveInfo di = new DriveInfo(dr);
            if (!di.IsReady) {
                //skip if drive not ready
                continue;
            }
            DirectoryInfo rootDir = di.RootDirectory;
            WalkDirectoryTree(rootDir);
        }
    }

    private void WalkDirectoryTree(DirectoryInfo root) {
        FileInfo[] files = null;
        DirectoryInfo[] subDirs = null;
        try {
            files = root.GetFiles("*.mp3");
        } catch (UnauthorizedAccessException e) {

        } catch (DirectoryNotFoundException e) {

        }

        if (files != null) {
            foreach (FileInfo fileInfo in files) {
                seachResults.Add(fileInfo.FullName);
            }
            subDirs = root.GetDirectories();
            foreach (DirectoryInfo dirInfo in subDirs) {
                WalkDirectoryTree(dirInfo);
            }
        }
    }
}

But when I try to migrate this into winRT app I get a few errors like unknown type Drive and unexisted method Environment.GetLogicalDrives() .

Can anyone say how do that in winRT?

Answer 1

You won't find a method for getting all logical drives in a WinRT app; WinRT apps exist in a sandboxed environment and will only have access to their own isolated storage or known folders (such as music) if declared as a capability in the application manifest.

For example, to get access to the user's music folder you can do this (don't forget to declare the capability in the app manifest):

StorageFolder folder = Windows.Storage.KnownFolders.MusicLibrary;

The only way to get access to any other part of the file system is if the user specifically grants access via a file picker:

var folderPicker = new FolderPicker();
var folder = await folderPicker.PickSingleFolderAsync();

Answer 2

Have you tried System.IO.Directory.GetLogicalDrives() ?

I believe that Environment.GetLogicalDrives() only works for Win32/Win64. If I am not mistaken System.IO.Directory exists in mscorlib, and is widely available across Phone, RT, or Regular versions.

The MSDN reference:

https://msdn.microsoft.com/en-us/library/system.io.directory.getlogicaldrives%28v=vs.110%29.aspx