vb.net 在树视图中显示所有驱动器、文件和子文件夹
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Display all drives, files, and subfolders in treeview
提问by user2658544
I'm looking for the simplest way to display all drives, files, and subfolders in a treeview. If someone's got a snippet of code to do this that they don't mind sharing I would really appreciate it.
我正在寻找在树视图中显示所有驱动器、文件和子文件夹的最简单方法。如果有人有一段代码可以做到这一点，并且他们不介意分享，我会非常感激。
The closest I've gotten was this code I tried using, but it gave me a "IOException was unhandled" error saying "The device is not ready." error at runtime (after about 5-10 sec) on the line below
我得到的最接近的是我尝试使用的这段代码，但它给了我一个“IOException 未处理”错误，说“设备未准备好”。运行时错误（大约 5-10 秒后）在下面的行
Dim folders() As String = IO.Directory.GetDirectories(dir)
underneath is the rest of the code
下面是其余的代码
Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim drives As System.Collections.ObjectModel.ReadOnlyCollection(Of IO.DriveInfo) = My.Computer.FileSystem.Drives
Dim rootDir As String = String.Empty
For i As Integer = 0 To drives.Count - 1
rootDir = drives(i).Name
TreeView1.Nodes.Add(rootDir)
PopulateTreeView(rootDir, TreeView1.Nodes(i))
Next
End Sub
Private Sub PopulateTreeView(ByVal dir As String, ByVal parentNode As TreeNode)
Dim folder As String = String.Empty
Try
Dim folders() As String = IO.Directory.GetDirectories(dir)
If folders.Length <> 0 Then
Dim childNode As TreeNode = Nothing
For Each folder In folders
childNode = New TreeNode(folder)
parentNode.Nodes.Add(childNode)
PopulateTreeView(folder, childNode)
Next
End If
Catch ex As UnauthorizedAccessException
parentNode.Nodes.Add(folder & ": Access Denied")
End Try
End Sub
回答by Steven Liekens
Seems like you're off to a good start. The IOExceptionyou receive is most likely caused by your procedure trying to list contents on an empty disc drive, which is obviously impossible.
看起来你有一个好的开始。在IOException您收到很可能是你的程序试图列表内容为空光盘驱动器，这显然是不可能造成。
The fix is simple:
修复很简单：
For i As Integer = 0 To drives.Count - 1
If Not drives(i).IsReady Then
Continue For
End If
rootDir = drives(i).Name
TreeView1.Nodes.Add(rootDir)
PopulateTreeView(rootDir, TreeView1.Nodes(i))
Next
Besides that, I recommend not loading folder contents until a node is clicked. Limit the recursive call to 1 level (current directory + content of all its subdirectories). That way, you get the best performance while still being able to determine whether a subdirectory should have the treeview expand button.
除此之外，我建议在单击节点之前不要加载文件夹内容。将递归调用限制为 1 级（当前目录 + 其所有子目录的内容）。这样，您可以获得最佳性能，同时仍然能够确定子目录是否应具有树视图展开按钮。
