You can use c# to edit web pages in vs to solve problems or provide related books and e-books.

//This is Winform's. You can refer to it

Private? Invalid? BtAdd_Click (object? Sender? EventArgs？ e)

{

//? Add layer 0

TreeNode？ part 1？ =? this.treeView_Items。 nodes . Add(" C:")；

TreeNode？ Part two? =? this.treeView_Items。 nodes . Add(" D:")；

//? Add layer 1

TreeNode？ part3=part 1。 nodes . Add(" file 1 ")；

TreeNode？ part4=part 1。 nodes . Add(" file 2 ")；

TreeNode？ Part 5 = Part 2. nodes . Add(" file 3 ")；

TreeNode？ Part 6 = Part 2. nodes . Add(" file 4 ")；

//? Add layer 2

The third part. nodes . Add(" ab . txt ")；

The fourth part. nodes . Add(" 12 . MP3 ")；

The fifth part. nodes . Add(" ab . MP4 ")；

The sixth part. nodes . Add(" 1 . wav ")；

}

Private? Invalid? treeView _ Items _ after select(object？ Sender? TreeViewEventArgs？ e)

{

Process. start(e . node . full path)；

MessageBox。 show(e . node . full path)；

}

//This is C#? Web？ Please refer to the details for the corresponding part. You can find the data from the database first, and then add the child nodes in turn. //Instantiate the root node object.

TreeNode？ objTreeNode？ =? New? TreeNode()；

//The value of the root node

objTreeNode。 Value? =? drArray[i]["ATTRIBUTE_CODE"]。 ToString()

+? " & amp？ +? drArray[i]["VERSION"]。 ToString()；

//The displayed value of the root node

objTreeNode。 Words? =? DrArray[i][ "property name"]. ToString()；

//Show the root node on the mouse.

objTreeNode。 Tooltips? =? drArray[i]["ATTRIBUTE_CODE"]。 ToString()

+? "?" ? +? DrArray[i][ "property name"]. ToString()；

//Add root node

treeNode。 add(objTreeNode)；

//? Click the 4th level menu to play the file pointed by the menu on the right.

Protected? Invalid? treeview 1 _ TreeNodeCheckChanged(object？ Sender? TreeNodeEventArgs？ e)

{

String? s = e . Node.DataPath

}