.NET C# 在 WinForms 中使用 TreeView，如选项卡控件

Question

I want to use TreeView in my software so when user clicks a node, the content of the Form will be changed. Example in this picture, but also I want to grab user input from all forms.

WinForms TreeView example

https://youtu.be/9BdYzMDxl9M?t=46

TreeView -> Node -> User Click -> Display Form_X in the GroupBox

I tried but I could not find related resources on this topic so I posted this question. Thank you for your help

Answer 1

Don't use forms as child controls. User controls exist specifically for that so use them. You add a user control to a project in the same way as you do a form, simply selecting a different menu option. You then design it and add code to it just as you would a form. Once you build your project, the user control will appear in the Toolbox and you can use it just like you would any other control. You then have a couple of options for how to handle switching controls via the TreeView .

If the number of controls is fairly small, you can add one of each to the GroupBox in the designer, so they all exist all the time. You would probably want to set the Dock property of each to Fill , so they all fill the parent GroupBox . In the Load event handler of the form, you can assign each user control instance to the Tag property of the corresponding TreeNode . When the user selects a node, you get the user control from its Tag property and call BringToFront on it, so the user will see it and it will hide all the other user controls, eg

private void Form1_Load(object sender, EventArgs e)
{
    var nodes = treeView1.Nodes;

    nodes[0].Tag = userControl1;
    nodes[1].Tag = userControl2;
    nodes[2].Tag = userControl3;
}

private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
{
    var userControl = treeView1.SelectedNode.Tag as Control;

    userControl?.BringToFront();
}

Because all the controls exist all the time, you can load all the data at the start and save all the changes at the end and not have to transfer any data when the selection changes.

If the number of controls is larger, you might want to show just one at a time. That becomes more complex because, when the selection changes, you have to make sure that any changes in the current user control are remembered, remove the existing control and then create and load the new control. Because the process is more complex, there are more options about exactly how to implement it. For that reason, I won't go into specifics here. If you want to go that way, you need to consider those options and how they relate to the specifics of your application and then decide how you want to implement the process. If you do that and encounter an issue along the way, that would be another question.

Answer 2

What have you tried? I am confident there are many ways to achieve what you describe. Since you mentioned a TabControl have you considered using a TabControl without the Tabs and manually switch to the proper tab page whenever the tree view node is clicked.

Something like…

private void Form1_Load(object sender, EventArgs e) {
  tabControl1.Appearance = TabAppearance.FlatButtons;
  tabControl1.ItemSize = new Size(0, 1);
  tabControl1.SizeMode = TabSizeMode.Fixed;
}

private void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e) {
  if (e.Node.Name == "TabPage1") {
    tabControl1.SelectTab("TabPage1");
  }
  else {
    tabControl1.SelectTab("TabPage2");
  }
}