TcxCustomTreeList.StoreDataViewState(TcxTreeListStorageOptions) Method

Stores specified user interaction states in memory.

Declaration

procedure StoreDataViewState(AOptions: TcxTreeListStorageOptions);

Parameters

Name	Type	Description
AOptions	TcxTreeListStorageOptions	Specifies a set of individual user interaction states stored in memory.

Remarks

Call StoreDataViewState and RestoreDataViewState procedures to save and restore specified user interaction states (selection, focus, node expanded status, etc.) during the same session.

Note

A RestoreDataViewState call clears all user interaction states saved using the StoreDataViewState procedure.

If you need to store user interaction states in a stream, call StoreDataViewStateToStream and RestoreDataViewStateFromStream procedures.

Tree List User Interaction States

Pass a set of all required flags^[1] as the AOptions parameter to restore corresponding Tree List user interaction states:

tsoFocusedItem | tsoFocusedRecord

Store the focus position.

tsoSelected

Stores selection.

tsoTopRecord

Stores the Tree List scroll position (the record at the top control border).

tsoExpanded

Stores the expanded status for all nodes.

Note

The tsoUseDataViewState flag has no effect on StoreDataViewState/RestoreDataViewState and StoreDataViewStateToStream/RestoreDataViewStateFromStream calls.

Use tsoUseDataViewState in StoreToIniFile/RestoreFromIniFile, StoreToRegistry/RestoreFromRegistry, and StoreToStream/RestoreFromStream calls to save/restore user interaction states in addition to the data layout.

Code Example: Restore User Interaction States after Data Refresh

The following code example restores selection, focus and scroll positions, and node expanded states after a refresh operation in the bound dataset:

Delphi

uses
  FireDAC.Comp.Client,  // Declares the TFDQuery component
  cxDBTL;  // Declares the TcxDBTreeList class
// ...

  cxDBTreeList1.StoreDataViewState(cxTreeListStoreAllDataViewStates);
  FDQuery1.Refresh;
  cxDBTreeList1.RestoreDataViewState(cxTreeListStoreAllDataViewStates);

C++

#include "FireDAC.Comp.Client.hpp"  // Declares the TFDQuery component
#include "cxDBTL.hpp"  // Declares the TcxDBTreeList class

// Add the following linker directives to the corresponding CPP source file:
#pragma link "FireDAC.Comp.Client" // Required to use FireDAC.Comp.Client.hpp declarations
#pragma link "cxDBTL" // Required to use cxDBTL.hpp declarations

  cxDBTreeList1->StoreDataViewState(cxTreeListStoreAllDataViewStates);
  FDQuery1->Refresh();
  cxDBTreeList1->RestoreDataViewState(cxTreeListStoreAllDataViewStates);

Other Tree List Store/Restore Methods

Alternatively, you can store Tree List data layout and user interaction states in an INI file or the system registry. The TcxCustomTreeList class implements the following Store~/Restore~ method pairs in addition to StoreDataViewState and RestoreDataViewState:

StoreToIniFile | RestoreFromIniFile

Allow you to store the Tree List state (both data layout and user interaction states) in an INI file.

StoreToRegistry | RestoreFromRegistry

Allow you to store the Tree List state (both data layout and user interaction states) in the system registry.

StoreToStream | RestoreFromStream

Allow you to store the Tree List state (both data layout and user interaction states) in a stream.

StoreDataViewStateToStream | RestoreDataViewStateFromStream

Allow you to store user interaction states in a separate stream.

Footnotes

1. Alternatively, you can use only the cxTreeListStoreAllDataViewStates constant if you need to restore all user interaction states for the Tree List control as demonstrated in the code example in this topic.