CreateStreamCallback (Delegado)
Proporciona una secuencia al control ReportViewer para la presentación.
Espacio de nombres: Microsoft.Reporting.WinForms
Ensamblado: Microsoft.ReportViewer.WinForms (en Microsoft.ReportViewer.WinForms.dll)
Sintaxis
'Declaración
Public Delegate Function CreateStreamCallback ( _
name As String, _
extension As String, _
encoding As Encoding, _
mimeType As String, _
willSeek As Boolean _
) As Stream
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 no admite delegados.
Parámetros
- name
Tipo: String
El nombre de la secuencia.
- extension
Tipo: String
La extensión de nombre de archivo que se utiliza si se está creando una secuencia de archivos.
- encoding
Tipo: Encoding
Un valor de enumerador Encoding que especifica la codificación de caracteres de la secuencia.Puede ser una nullreferencia null (Nothing en Visual Basic) si la secuencia no contiene caracteres.
- mimeType
Tipo: String
Un valor string que contiene el tipo MIME de la secuencia.
- willSeek
Tipo: Boolean
Un valor Boolean que indica si la secuencia debe admitir búsquedas.Si el valor es false, la secuencia solo será de avance y se enviará al cliente en fragmentos a medida que se crea.Si el valor es true, la secuencia se puede escribir en cualquier orden.
Valor devuelto
Tipo: Stream
Un objeto Stream en el que el control ReportViewer puede escribir datos.
Comentarios
Esta función de delegado se puede pasar al método Render del objeto LocalReport para admitir el proceso personalizado de las secuencias secundarias.El cuerpo principal del informe es la primera secuencia que se crea.
Ejemplos
El siguiente fragmento de código muestra una función de devolución de llamada CreateStreamCallback que se pasa al método Render en una aplicación de consola.
Imports System.IO
Imports System.Data
Imports System.Text
Imports System.Drawing.Imaging
Imports System.Drawing.Printing
Imports System.Collections.Generic
Imports Microsoft.Reporting.WinForms
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.WinForms;
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_streans = null;
}
}
public static int Main(string[] args)
{
using (Demo demo = new Demo())
{
demo.Run();
}
return 0;
}
}