vcl-dxreport.md
An AI-powered Report Generator component.
TdxReport = class(
TcxCustomComponent
)
TdxReport is a non-visual component designed to generate customizable reports based on templates populated with placeholder fields. The report generator implementation is based on the DevExpress Javascript Report Designer and Viewer adapted for use in native VCL apps (using modern web-based design capabilities based on WebView and ASP.NET Core).
All required .NET and JS dependencies are embedded into one self-contained EXE file transparently.
Note
Ensure that your development environment meets ExpressDashboards and ExpressReports prerequisites:
Tip
Refer to the following topic for detailed information: VCL Reports/Dashboards App Deployment.
TdxReport can populate placeholder fields in a template from different data sources stored in memory or a database. The TdxBackendDataConnectionManager component allows you to manage data connection components designed to work with different data sources.
Tip
You can create data connection components directly in code, without TdxBackendDataConnectionManager.
Refer to the data connection class descriptions for detailed information and code examples.
TdxBackendDataSetJSONConnection
A component designed to work with data in one or multiple VCL-compatible datasets (TDataSet descendants).
Use the TdxBackendDataSetJSONConnection component if you need to use TdxDashboardControl/TdxDashboard and TdxReport components together with VCL-compatible data sources.
Refer to the following help topic for step-by-step instructions on using the TdxBackendDataSetJSONConnection component in your project:
VCL Reports/Dashboards: How to Use Data Source and Data Set Components
TdxBackendInMemoryJSONConnection
A component designed for interaction with local (in-memory) or remote JSON data accessible through a Web API service endpoint.
Refer to the following help topic for step-by-step instructions on using the TdxBackendInMemoryJSONConnection component as a data source for TdxDashboard/TdxDashboardControl and TdxReport:
VCL Reports/Dashboards: How to Use Memory-Based or Remote API Data Sources
TdxBackendDatabaseSQLConnection
A DevExpress XPO-based component designed to fetch data from the following relational databases:
SQLite | Microsoft SQL Server/Azure SQL | PostgreSQL | Oracle Database | MySQL | Firebird
Tip
This component is based on the DevExpress XPO ORM engine (powered by ADO.NET).
TdxBackendDatabaseSQLConnection has built-in support for Microsoft SQL/Azure SQL and SQLite engines (you can use them without additional dependencies and extra configuration).
Refer to the following topic for a complete list of supported database engines and corresponding connection string examples:
VCL Reports/Dashboards: Supported Database Engines
The list below outlines key members of the TdxReport class. These members allow you to configure templates, generate reports, and export report content in different target formats.
ClearClears the current report name, layout, and parameters.EnableCustomSql
Specifies if custom SQL queries are enabled at the TdxReport component level.
Important
Enable custom SQL queries only if you ensure that you follow best practices and implement user read/write privileges at the database level using the tools available for your relational database management system.
FilterStringSpecifies filter criteria for report data.GroupNameAllows you to group multiple TdxReport components. All components within the same group use shared VCL backend resources.LanguageAllows you to switch between available UI and report template localizations. Refer to the following topic for information on localization techniques: VCL Reports Localization.LayoutProvides access to the report REPX template (as individual XML strings).OnLayoutChangedAllows you to respond to any report layout changes.Parameters
Provides access to the read-only collection of report parameters.
Note
The Parameters collection is automatically populated and updated from the current report template definition.
ReportNameSpecifies the report name.
ExportFormatsSpecifies export formats available to users in the Report Preview dialog.OnExportAllows you to execute custom code in response to preview file download operations or to prevent users from downloading previews.OnDesignerFormShow | OnViewerFormShowAllow you to customize Report Designer and Report Viewer dialog form settings (position, dimensions, caption, etc.).OnPrintPreviewAllows you to respond to print preview operations and obtain preview content as a PDF document.ShowDesigner | ShowViewer
Display Web-based Report Designer and Report Preview dialogs. Global skin and palette settings (defined using the Project Settings dialog or a TdxSkinController component) affect these dialogs.
Tip
You can click the Designer… or Viewer… item in the TdxReport component’s context menu to display the corresponding dialog at design time.
ExportToExports the current report to a stream in any supported format.ExportToCSV | ExportToDOCX | ExportToHTML | ExportToMHT | ExportToPDF | ExportToRTF | ExportToRTF | ExportToText | ExportToXLS | ExportToXLSXExport the current report to a stream in corresponding formats.ExportToImage
Exports the current report to a stream as an image (PNG is the default image export format).
Tip
The current image format is defined in Export Options available in the Web-based Report Preview dialog.
GetExportResultFileNameReturns the full report file name for export operations.
View Example: Store Report Layouts within Text FilesView Example: Store Report Layouts in a DatabaseView Example: Localize the DevExpress Report Viewer and Report Designer
The following code example uses the TdxBackendDatabaseSQLConnection component to connect to a demo database (devav.sqlite3), displays the Report Designer dialog, and saves all changes made to the UserReport.repx file:
uses
dxReport, // Declares the TdxReport component and related types
dxBackend.ConnectionString.SQL; // Declares the TdxBackendDatabaseSQLConnection component
// ...
procedure TMyForm.Button1Click(Sender: TObject);
var
ADataConnection: TdxBackendDatabaseSQLConnection;
AReport: TdxReport;
begin
ADataConnection := TdxBackendDatabaseSQLConnection.Create(Self); // Creates a database connection
try
ADataConnection.Name := 'SQLite Database Connection';
// Specify a connection string required to connect to a demo database (devav.sqlite3)
ADataConnection.ConnectionString := 'XpoProvider=SQLite;' + // Specifies the database engine type
'Data Source=C:\Users\Public\Documents\DevExpress VCL Demos\MegaDemos\' +
'Product Demos\ExpressReports\Data\devav.sqlite3';
AReport := TdxReport.Create(Self); // Creates a TdxReport component
try
AReport.ShowDesigner; // Displays the Report Designer dialog
AReport.Layout.SaveToFile('UserReport.repx'); // Saves the report template state to a file
finally
AReport.Free; // Releases the created TdxReport component
end;
finally
ADataConnection.Free; // Releases the database connection component
end;
end;
#include "dxReport.hpp" // Declares the TdxReport component and related types
#include "dxBackend.ConnectionString.SQL.hpp" // Declares the TdxBackendDatabaseSQLConnection component
// Add the following linker directives to the corresponding CPP source file:
#pragma link "dxReport" // Required to use dxReport.hpp declarations
#if defined(_WIN64) // Required to use dxBackend.ConnectionString.SQL.hpp declarations
#pragma link "dxBackend.ConnectionString.SQL.o"
#else
#pragma link "dxBackend.ConnectionString.SQL.obj"
// ...
void __fastcall TMyForm::Button1Click(TObject *Sender)
{
TdxBackendDatabaseSQLConnection *ADataConnection;
TdxReport *AReport;
ADataConnection = new TdxBackendDatabaseSQLConnection(this); // Creates a database connection
try
{
ADataConnection->Name = "SQLite Database Connection";
// Specify a connection string required to connect to a demo database (devav.sqlite3)
ADataConnection->ConnectionString = "XpoProvider=SQLite;" // Specifies the database engine type
"Data Source=C:\\Users\\Public\\Documents\\DevExpress VCL Demos\\MegaDemos\\"
"Product Demos\\ExpressReports\\Data\\devav.sqlite3";
AReport = new TdxReport(this); // Creates a TdxReport component
try
{
AReport->ShowDesigner(); // Displays the Report Designer dialog
AReport->Layout->SaveToFile("UserReport.repx"); // Saves the report template state to a file
}
__finally
{
delete AReport; // Releases the created TdxReport component
}
}
__finally
{
delete ADataConnection; // Releases the database connection component
}
}
To see the TdxReport component in action, run the Report Designer/Viewer demo in the VCL Demo Center installed with compiled DevExpress VCL demos. Click different items in the sidebar on the left to switch between demo features.
Tip
You can find full source code for the installed compiled Report demo in the following folder:
_%PUBLIC%\Documents\DevExpress VCL Demos\MegaDemos\Product Demos\ExpressReports_
TObject TPersistent TComponent TcxCustomComponent TdxReport
See Also