How can I use VirtualTreeView in Delphi

VirtualTreeView is a component for Delphi that allows you to create highly customizable tree-like structures for displaying hierarchical data. It is optimized for large datasets and provides various features such as sorting, filtering, and searching.

To use VirtualTreeView in Delphi, you will need to install the component from the Embarcadero GetIt Package Manager or by downloading it from the developer’s website. Once the component is installed, you can add it to your Delphi form as you would any other component.

Here is an example of how you can use VirtualTreeView to create a simple tree structure and populate it with data:

uses
  VirtualTrees;

type
  // Declare a record type to hold the data for each tree node.
  TNodeData = record
    Text: string;
  end;
  PNodeData = ^TNodeData;

procedure TForm1.FormCreate(Sender: TObject);
var
  RootNode, ChildNode: PVirtualNode;
  RootData, ChildData: PNodeData;
begin
  // Create the root node.
  RootNode := VirtualTreeView1.AddChild(nil);
  // Allocate a new record for the root node data.
  New(RootData);
  RootData.Text := ‘Root’;
  // Set the data for the root node.
  VirtualTreeView1.NodeData[RootNode] := RootData;

  // Create a child node.
  ChildNode := VirtualTreeView1.AddChild(RootNode);
  // Allocate a new record for the child node data.
  New(ChildData);
  ChildData.Text := ‘Child’;
  // Set the data for the child node.
  VirtualTreeView1.NodeData[ChildNode] := ChildData;
end;

procedure TForm1.VirtualTreeView1GetText(Sender: TBaseVirtualTree;
  Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;
  var CellText: string);
var
  Data: PNodeData;
begin
  // Get the data for the current node.
  Data := Sender.GetNodeData(Node);
  // Set the cell text to the Text field of the node data.
  CellText := Data.Text;
end;

uses

VirtualTrees;

type

// Declare a record type to hold the data for each tree node.

TNodeData = record

Text: string;

end;

PNodeData = ^TNodeData;

procedure TForm1.FormCreate(Sender: TObject);

var

RootNode, ChildNode: PVirtualNode;

RootData, ChildData: PNodeData;

begin

// Create the root node.

RootNode := VirtualTreeView1.AddChild(nil);

// Allocate a new record for the root node data.

New(RootData);

RootData.Text := ‘Root’;

// Set the data for the root node.

VirtualTreeView1.NodeData[RootNode] := RootData;

// Create a child node.

ChildNode := VirtualTreeView1.AddChild(RootNode);

// Allocate a new record for the child node data.

New(ChildData);

ChildData.Text := ‘Child’;

// Set the data for the child node.

VirtualTreeView1.NodeData[ChildNode] := ChildData;

end;

procedure TForm1.VirtualTreeView1GetText(Sender: TBaseVirtualTree;

Node: PVirtualNode; Column: TColumnIndex; TextType: TVSTTextType;

var CellText: string);

var

Data: PNodeData;

begin

// Get the data for the current node.

Data := Sender.GetNodeData(Node);

// Set the cell text to the Text field of the node data.

CellText := Data.Text;

end;

This example creates a root node and a child node, and sets the Text field of the node data to be displayed in the tree. You can use the VirtualTreeView1GetText event handler to customize the way the data is displayed in the tree.

You can find more information about using VirtualTreeView in the documentation that is included with the component, or on the developer’s website:

https://www.soft-gems.net/VirtualTreeView/

How can I use VirtualTreeView in Delphi

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