Merge Large Reports

• Nov 21, 2018
• 3 minutes to read

Use the CachedReportSource/CachedReportSourceWeb component to merge reports that include a large amount of data. This component allows you to avoid memory consumption-related issues by storing pages in a file system or database during document generation.

Note

There are certain limitations when merging reports.

Create a report document using the CachedReportSource component’s CreateDocument()/CreateDocumentAsync() method. Access the generated document’s pages using the CachedReportSource component’s PrintingSystem. Put pages in a specific order using the CachedReportSource component’s ModifyDocument(Action<IDocumentModifier>) method. The following code demonstrates how to add a report’s title page to the beginning of another report.

C#

using DevExpress.XtraReports.UI;
using DevExpress.XtraPrinting.Caching;
// ... 
private void CombineTwoReports() {
    var mainReportStorage = new MemoryDocumentStorage();
    var mainReport = new XtraReport1();
    var cachedMainReportSource = new CachedReportSource(mainReport, mainReportStorage);
    cachedMainReportSource.CreateDocument();

    var titleReportStorage = new MemoryDocumentStorage();
    var titleReport= new XtraReport2();
    var cachedTitleReportSource = new CachedReportSource(titleReport, titleReportStorage);
    cachedTitleReportSource.CreateDocument();

    cachedMainReportSource.ModifyDocument(x => {
        x.InsertPage(0, cachedTitleReportSource.PrintingSystem.Pages[0]);
    }
} 

VB.NET

Imports DevExpress.XtraReports.UI
Imports DevExpress.XtraPrinting.Caching
' ... 
Private Sub CombineTwoReports()
    Dim mainReportStorage = New MemoryDocumentStorage()
    Dim mainReport = New MyReport1()
    Dim cachedMainReportSource = New CachedReportSource(mainReport, mainReportStorage)
    cachedMainReportSource.CreateDocument()

    Dim titleReportStorage = New MemoryDocumentStorage()
    Dim titleReport= New MyReport2()
    Dim cachedTitleReportSource = New CachedReportSource(titleReport, titleReportStorage)
    cachedTitleReportSource.CreateDocument()

    cachedMainReportSource.ModifyDocument(Function(x)
        x.InsertPage(0, cachedTitleReportSource.PrintingSystem.Pages(0))
    End Function }
End Sub

The following code demonstrates how to use the ModifyDocument(Action<IDocumentModifier>) method to add a report’s pages to the end of another report.

C#

using DevExpress.XtraReports.UI;
using DevExpress.XtraPrinting.Caching;
// ...
private void CombineTwoReports() {
    // Create the 1st report and generate its document.    
    var storage1 = new MemoryDocumentStorage();
    var report1 = new XtraReport1();
    var cachedReportSource1 = new CachedReportSource(report1, storage1);
    cachedReportSource1.CreateDocument();
    // Create the 2nd report and generate its document.
    var storage2 = new MemoryDocumentStorage();
    var report2 = new XtraReport2();
    var cachedReportSource2 = new CachedReportSource(report2, storage2);
    cachedReportSource2.CreateDocument();

    // Add all pages of the 2nd report to the end of the 1st report.
    cachedReportSource1.ModifyDocument(x => {
        x.AddPages(cachedReportSource2.PrintingSystem.Pages);
    };

    // Preview the 1st report using the cachedReportSource1 object
    // ...
} 

VB.NET

Imports DevExpress.XtraReports.UI
Imports DevExpress.XtraPrinting.Caching
' ...
Private Sub CombineTwoReports()
    ' Create the 1st report and generate its document.    
    Dim storage1 = New MemoryDocumentStorage()
    Dim report1 = New XtraReport1()
    Dim cachedReportSource1 = New CachedReportSource(report1, storage1)
    cachedReportSource1.CreateDocument()
    ' Create the 2nd report and generate its document.
    Dim storage2 = New MemoryDocumentStorage()
    Dim report2 = New XtraReport2()
    Dim cachedReportSource2 = New CachedReportSource(report2, storage2)
    cachedReportSource2.CreateDocument()

    ' Add all pages of the 2nd report to the end of the 1st report.
    cachedReportSource1.ModifyDocument(Function(x)
        x.AddPages(cachedReportSource2.PrintingSystem.Pages)
    End Function
    ' Preview the 1st report using the cachedReportSource1 object
    ' ...