Delphi TreeView Usage Guide

The Delphi TreeView is a control used to display hierarchical data on a form. You can utilize the following steps to use the Delphi TreeView control:

1. Place a TreeView control on the form. You can drag and drop a TreeView control from the control panel onto the form.
2. Set some basic properties of the TreeView, such as Name, Align, Width, and Height.
3. Initialize the TreeView control in the code. You can add code to initialize the TreeView control in the OnCreate event of the form. For example:

procedure TForm1.FormCreate(Sender: TObject);
begin
  TreeView1.Items.Clear; // 清空TreeView

  // 添加根节点
  TreeView1.Items.Add(nil, 'Root');

  // 添加子节点
  TreeView1.Items.AddChild(TreeView1.Items[0], 'Child 1');
  TreeView1.Items.AddChild(TreeView1.Items[0], 'Child 2');

  // 展开根节点
  TreeView1.Items[0].Expand(True);
end;

1. You can use the Items property of TreeView to add, remove, and modify tree nodes. For example:

// 添加树节点
TreeView1.Items.AddChild(TreeView1.Selected, 'New Node');

// 删除树节点
TreeView1.Items.Delete(TreeView1.Selected);

// 修改树节点的文本
TreeView1.Selected.Text := 'Modified Node';

1. One way to handle user operations is by using events in TreeView. For example, you can use the OnDblClick event in TreeView to respond to double-clicking on a tree node.

procedure TForm1.TreeView1DblClick(Sender: TObject);
begin
  // 获取双击的树节点
  if Assigned(TreeView1.Selected) then
  begin
    ShowMessage('Double clicked on ' + TreeView1.Selected.Text);
  end;
end;

By following the above steps, you can use the TreeView control in Delphi to build and manage hierarchical data structures.