CreateStreamCallback-Delegat
Stellt für das ReportViewer-Steuerelement einen Datenstrom zum Rendern bereit.
Namespace: Microsoft.Reporting.WebForms
Assembly: Microsoft.ReportViewer.WebForms (in Microsoft.ReportViewer.WebForms.dll)
Syntax
'Declaration
Public Delegate Function CreateStreamCallback ( _
name As String, _
extension As String, _
encoding As Encoding, _
mimeType As String, _
willSeek As Boolean _
) As Stream
'Usage
Dim instance As New CreateStreamCallback(AddressOf HandlerMethod)
public delegate Stream CreateStreamCallback(
string name,
string extension,
Encoding encoding,
string mimeType,
bool willSeek
)
public delegate Stream^ CreateStreamCallback(
String^ name,
String^ extension,
Encoding^ encoding,
String^ mimeType,
bool willSeek
)
type CreateStreamCallback =
delegate of
name:string *
extension:string *
encoding:Encoding *
mimeType:string *
willSeek:bool -> Stream
JScript unterstützt die Verwendung von Delegaten, jedoch nicht die Deklaration neuer Delegate.
Parameter
- name
Typ: System.String
Der Name des Datenstroms.
- extension
Typ: System.String
Die zu verwendende Dateinamenerweiterung, falls ein Dateidatenstrom erstellt wird.
- encoding
Typ: System.Text.Encoding
Ein Encoding-Enumeratorwert, der die Zeichencodierung des Datenstroms angibt. Dieser Wert kann nullein NULL-Verweis (Nothing in Visual Basic) sein, wenn der Datenstrom keine Zeichen enthält.
- mimeType
Typ: System.String
Ein string-Wert, der den MIME-Typ des Datenstroms enthält.
- willSeek
Typ: System.Boolean
Ein Boolean-Wert, der angibt, ob Suchvorgänge vom Datenstrom unterstützt werden müssen. Lautet der Wert false, wird der Datenstrom nur weitergeleitet und während der Erstellung segmentweise an den Client gesendet. Lautet der Wert true, kann der Datenstrom in beliebiger Reihenfolge geschrieben werden.
Rückgabewert
Typ: System.IO.Stream
Ein Stream-Objekt, in das das ReportViewer-Steuerelement Daten schreiben kann.
Hinweise
Diese Delegatfunktion kann zur Unterstützung der benutzerdefinierten Behandlung von sekundären Datenströmen an die Render(IRenderingExtension, String, String, CreateAndRegisterStream, array<Warning[]%)-Methode des LocalReport()-Objekts übergeben werden. Aus dem Hauptteil des Berichts wird der erste Datenstrom erstellt.
Beispiele
Im folgenden Codeausschnitt wird gezeigt, wie eine CreateStreamCallback-Rückruffunktion an die Render(IRenderingExtension, String, String, CreateAndRegisterStream, array<Warning[]%)-Methode übergeben wird.
Imports System.IO
Imports System.Data
Imports System.Text
Imports System.Drawing.Imaging
Imports System.Drawing.Printing
Imports System.Collections.Generic
Imports Microsoft.Reporting.WebForms
Public Class Demo
Implements IDisposable
private m_currentPageIndex As Integer
private m_streams As IList(Of Stream)
Private Function LoadSalesData() As DataTable
Dim dataSet As New DataSet()
dataSet.ReadXml("data.xml")
Return dataSet.Tables(0)
End Function
Private Function CreateStream(name As String, _
fileNameExtension As String, _
encoding As Encoding, mimeType As String, _
willSeek As Boolean) As Stream
Dim stream As Stream = New FileStream(name + "." + fileNameExtension, FileMode.Create)
m_streams.Add(stream)
Return stream
End Function
Private Sub Export(report As LocalReport)
Dim deviceInfo As string = _
"<DeviceInfo>" + _
" <OutputFormat>EMF</OutputFormat>" + _
" <PageWidth>8.5in</PageWidth>" + _
" <PageHeight>11in</PageHeight>" + _
" <MarginTop>0.25in</MarginTop>" + _
" <MarginLeft>0.25in</MarginLeft>" + _
" <MarginRight>0.25in</MarginRight>" + _
" <MarginBottom>0.25in</MarginBottom>" + _
"</DeviceInfo>"
Dim warnings() As Warning = Nothing
m_streams = New List(Of Stream)()
report.Render("Image", deviceInfo, _
AddressOf CreateStream, warnings)
Dim stream As Stream
For Each stream In m_streams
stream.Position = 0
Next
End Sub
Private Sub PrintPage(sender As Object, ev As PrintPageEventArgs)
Dim pageImage As New Metafile(m_streams(m_currentPageIndex))
ev.Graphics.DrawImage(pageImage, ev.PageBounds)
m_currentPageIndex += 1
ev.HasMorePages = (m_currentPageIndex < m_streams.Count)
End Sub
Private Sub Print()
Const printerName As String = "Microsoft Office Document Image Writer"
If m_streams Is Nothing Or m_streams.Count = 0 Then
Return
End If
Dim printDoc As New PrintDocument()
printDoc.PrinterSettings.PrinterName = printerName
If Not printDoc.PrinterSettings.IsValid Then
Dim msg As String = String.Format(_
"Can't find printer ""{0}"".", printerName)
Console.WriteLine(msg)
Return
End If
AddHandler printDoc.PrintPage, AddressOf PrintPage
printDoc.Print()
End Sub
Private Sub Run()
Dim report As LocalReport = new LocalReport()
report.ReportPath = "Report.rdlc"
report.DataSources.Add(new ReportDataSource("Sales", LoadSalesData()))
Export(report)
m_currentPageIndex = 0
Print()
End Sub
Public Overloads Sub Dispose() Implements IDisposable.Dispose
If Not (m_streams Is Nothing) Then
Dim stream As Stream
For Each stream In m_streams
stream.Close()
Next
m_streams = Nothing
End If
End Sub
Public Shared Sub Main(args as string())
Using demo As Demo = new Demo()
demo.Run()
End Using
End Sub
End Class
using System;
using System.IO;
using System.Data;
using System.Text;
using System.Drawing.Imaging;
using System.Drawing.Printing;
using System.Collections.Generic;
using Microsoft.Reporting.WebForms;
public class Demo : IDisposable
{
private int m_currentPageIndex;
private IList<Stream> m_streams;
private DataTable LoadSalesData()
{
DataSet dataSet = new DataSet();
dataSet.ReadXml("data.xml");
return dataSet.Tables[0];
}
private Stream CreateStream(string name, string fileNameExtension,
Encoding encoding,
string mimeType, bool willSeek)
{
Stream stream = new FileStream(name + "." + fileNameExtension,
FileMode.Create);
m_streams.Add(stream);
return stream;
}
private void Export(LocalReport report)
{
string deviceInfo =
"<DeviceInfo>" +
" <OutputFormat>EMF</OutputFormat>" +
" <PageWidth>8.5in</PageWidth>" +
" <PageHeight>11in</PageHeight>" +
" <MarginTop>0.25in</MarginTop>" +
" <MarginLeft>0.25in</MarginLeft>" +
" <MarginRight>0.25in</MarginRight>" +
" <MarginBottom>0.25in</MarginBottom>" +
"</DeviceInfo>";
Warning[] warnings;
m_streams = new List<Stream>();
report.Render("Image", deviceInfo, CreateStream, out warnings);
foreach (Stream stream in m_streams)
stream.Position = 0;
}
private void PrintPage(object sender, PrintPageEventArgs ev)
{
Metafile pageImage = new Metafile(m_streams[m_currentPageIndex]);
ev.Graphics.DrawImage(pageImage, 0, 0);
m_currentPageIndex++;
ev.HasMorePages = (m_currentPageIndex < m_streams.Count);
}
private void Print()
{
const string printerName = "Microsoft Office Document Image
Writer";
if (m_streams == null || m_streams.Count == 0)
return;
PrintDocument printDoc = new PrintDocument();
printDoc.PrinterSettings.PrinterName = printerName;
if (!printDoc.PrinterSettings.IsValid)
{
string msg = String.Format("Can't find printer \"{0}\".",
printerName);
Console.WriteLine(msg);
return;
}
printDoc.PrintPage += new PrintPageEventHandler(PrintPage);
printDoc.Print();
}
private void Run()
{
LocalReport report = new LocalReport();
report.ReportPath = "Report.rdlc";
report.DataSources.Add(new ReportDataSource("Sales",
LoadSalesData()));
Export(report);
m_currentPageIndex = 0;
Print();
}
public void Dispose()
{
if (m_streams != null)
{
foreach (Stream stream in m_streams)
stream.Close();
m_streams = null;
}
}
public static int Main(string[] args)
{
using (Demo demo = new Demo())
{
demo.Run();
}
return 0;
}
}