Question

我需要有关如何将驱动器映射到树视图的帮助。我可以让我的驱动器显示，但我无法获得所有的子目录。我想把我的整个驱动器映射到树视图中。任何帮助，将不胜感激。这是我到目前为止所得到的。

        string[] drives = Environment.GetLogicalDrives();
        foreach (string dr in drives)
        {
            TreeNode node = new TreeNode(dr);
            node.Tag = dr;
            treeView1.Nodes.Add(node);
        }
        treeView1.CollapseAll();

Answer 1

递归地执行：

private void fillTree() { // you allready had most of this
  string[] drives = Environment.GetLogicalDrives();
  foreach(string dr in drives) {
    TreeNode node = RecursiveDirWalk(dr);
    node.ImageIndex = 0; // drive icon
    node.Tag = dr;
    treeView1.Nodes.Add(node);
  }
}

// now add this
private TreeNode RecursiveDirWalk(string path) {
  TreeNode node = new TreeNode(path.Substring(path.LastIndexOf('\\')));
  node.ImageIndex = 1; // dir icon
  node.Tag = path;
  string[] dirs = System.IO.Directory.GetDirectories(path);
  for(int t = 0; t < dirs.Length; t++) {
    node.Nodes.Add(RecursiveDirWalk(dirs[t]));
  }

  // Optional if you want files as well:
  string[] files = System.IO.Directory.GetFiles(path);
  for(int t = 0; t < files.Length; t++) {
    TreeNode tn = new TreeNode(System.IO.Path.GetFileName(files[t]));
    tn.Tag = files[t];
    tn.ImageIndex = 2; // file icon
    node.Nodes.Add(tn);
  } // end of optional file part

  return node;
}

Answer 2

这是一个延迟加载版本：

private void fillTree() { 
  string[] drives = Environment.GetLogicalDrives();
  foreach(string dr in drives) {
    TreeNode node = new TreeNode(dr);
    node.Tag = dr;
    node.ImageIndex = 0; // drive icon
    node.Tag = dr;
    treeView1.Nodes.Add(node);
    node.Nodes.Add(new TreeNode("?"));
  }
  treeView1.BeforeExpand += new TreeViewCancelEventHandler(treeView1_BeforeExpand);
}

void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e) {
  if((e.Node.Nodes.Count == 1) && (e.Node.Nodes[0].Text=="?")) {
    RecursiveDirWalk(e.Node);
  }
}

private TreeNode RecursiveDirWalk(TreeNode node) {
  string path = (string)node.Tag;
  node.Nodes.Clear();
  string[] dirs = System.IO.Directory.GetDirectories(path);
  for(int t = 0; t < dirs.Length; t++) {
    TreeNode n = new TreeNode(dirs[t].Substring(dirs[t].LastIndexOf('\\')+1));
    n.ImageIndex = 1; // dir icon
    n.Tag = dirs[t];
    node.Nodes.Add(n);
    n.Nodes.Add(new TreeNode("?"));
  }

  // Optional if you want files as well:
  string[] files = System.IO.Directory.GetFiles(path);
  for(int t = 0; t < files.Length; t++) {
    TreeNode tn = new TreeNode(System.IO.Path.GetFileName(files[t]));
    tn.Tag = files[t];
    tn.ImageIndex = 2; // file icon
    node.Nodes.Add(tn);
  } // end of optional file part

  return node;
}

Answer 3

以下是用于显示树的代码，该树仅包含首先显示的驱动器，当用户单击节点时添加到树中。此代码不会显示空驱动器。向每个节点添加图标留给学生练习：

select Month, Item,
       (events + party + spirit + faith) as counts
from t;

将整个驱动器映射到树视图

3 个答案: