c#如何在运行时动态添加树节点
我试图在运行时动态地将节点添加到现有的树视图模拟windows资源管理器中。我有可以工作的代码，但由于发生了大量的递归，它需要2-3分钟来检查c:驱动器上的所有文件并创建树。
我想要做的事情是这样的：
-NodeClickEvent-
if has children { do nothing }
else { add children and grandchildren to selected node }这是因为它不必加载整个树，而是每次单击一次加载几个层。
回答 3
Stack Overflow用户
发布于 2013-06-22 21:02:54
感谢所有的输入；我想我终于想出了如何在这里做我想要做的事情：An unhandled exception of type 'System.NullReferenceException' occurring when clicking TreeNode
我的代码是：
public Form1()
{
InitializeComponent();
this.treeView1.NodeMouseClick += new TreeNodeMouseClickEventHandler(this.treeView1_NodeMouseClick);
PopulateTreeView();
}
private void PopulateTreeView()
{
TreeNode rootNode;
DirectoryInfo info = new DirectoryInfo(@"c:\\");
if (info.Exists)
{
rootNode = new TreeNode(info.Name);
rootNode.Tag = info;
GetDirectories(info.GetDirectories(), rootNode);
treeView1.Nodes.Add(rootNode);
}
}
private void GetDirectories(DirectoryInfo[] subDirs, TreeNode nodeToAddTo)
{
TreeNode aNode;
//DirectoryInfo[] subSubDirs;
foreach (DirectoryInfo subDir in subDirs)
{
aNode = new TreeNode(subDir.Name, 0, 0);
aNode.Tag = subDir;
aNode.ImageKey = "folder";
/* try
{
subSubDirs = subDir.GetDirectories();
if (subSubDirs.Length != 0)
{
GetDirectories2(subSubDirs, aNode);
}
}
catch (System.UnauthorizedAccessException)
{
subSubDirs = new DirectoryInfo[0];
}*/
nodeToAddTo.Nodes.Add(aNode);
}
}
void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
try
{
DirectoryInfo d = new DirectoryInfo(@e.Node.FullPath);
if (e.Node.Nodes.Count > 0) { /*Do Nothing.*/ } else { GetDirectories(d.GetDirectories(), e.Node); e.Node.Expand(); }
TreeNode newSelected = e.Node;
listView1.Items.Clear();
DirectoryInfo nodeDirInfo = (DirectoryInfo)newSelected.Tag;
ListViewItem.ListViewSubItem[] subItems;
ListViewItem item = null;
foreach (DirectoryInfo dir in nodeDirInfo.GetDirectories())
{
item = new ListViewItem(dir.Name, 0);
subItems = new ListViewItem.ListViewSubItem[]
{new ListViewItem.ListViewSubItem(item, "Directory"),
new ListViewItem.ListViewSubItem(item,
dir.LastAccessTime.ToShortDateString())};
item.SubItems.AddRange(subItems);
listView1.Items.Add(item);
}
foreach (FileInfo file in nodeDirInfo.GetFiles())
{
item = new ListViewItem(file.Name, 1);
subItems = new ListViewItem.ListViewSubItem[]
{ new ListViewItem.ListViewSubItem(item, "File"),
new ListViewItem.ListViewSubItem(item,
file.LastAccessTime.ToShortDateString())};
item.SubItems.AddRange(subItems);
listView1.Items.Add(item);
}
listView1.AutoResizeColumns(ColumnHeaderAutoResizeStyle.HeaderSize);
}
catch (Exception ex)
{
if (ex is System.NullReferenceException || ex is System.UnauthorizedAccessException)
{
// Do Nothing.
}
}
}`Stack Overflow用户
发布于 2013-06-22 04:52:39
http://www.codeproject.com/Articles/26288/Simplifying-the-WPF-TreeView-by-Using-the-ViewMode
查看同一篇文章中的演示2
创建树视图项目时，在每个树视图项目展开时附加一个虚拟对象，如果虚拟子项在其中，则删除该虚拟子项，如果有，则添加实际的子项。
上面引用的文章很清楚地解释了这一点
Stack Overflow用户
发布于 2013-06-22 12:52:15
如果你对树形视图不是很熟悉，那么你可以先学习本教程http://www.dotnetperls.com/treeview，本教程将介绍如何使用树形列表。
下面的链接解释了你正在寻找的东西
http://msdn.microsoft.com/en-us/library/aa984278%28VS.71%29.aspx
http://msdn.microsoft.com/en-us/library/aa645739%28v=vs.71%29.aspx
https://stackoverflow.com/questions/17243843
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