IFileData.LoadFromStream(String, Stream) Method

Loads the file data from a stream.

Namespace: DevExpress.Persistent.Base

Assembly: DevExpress.Persistent.Base.v20.2.dll

Declaration

C#

void LoadFromStream(
    string fileName,
    Stream stream
)

VB.NET

Sub LoadFromStream(
    fileName As String,
    stream As Stream
)

Parameters

Name	Type	Description
fileName	String	A string that is the file name.
stream	Stream	A Stream that is the file content.

Remarks

The example below demonstrates how to use the LoadFromStream method to upload a Contact’s file into a portfolio.

C#

using System.IO;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl;
using MainDemo.Module.BusinessObjects;
// ...
public class UpdatePortfolioController : ObjectViewController<DetailView, Resume> {
    public UpdatePortfolioController() {
        SimpleAction updatePortfolioAction = new SimpleAction(this, "UpdatePortfolio", PredefinedCategory.Edit);
        updatePortfolioAction.SelectionDependencyType = SelectionDependencyType.RequireSingleObject;
        updatePortfolioAction.Execute += updatePortfolioAction_Execute;
    }
    private void updatePortfolioAction_Execute(object sender, SimpleActionExecuteEventArgs e) {
        FileData currentFile = ViewCurrentObject.File;
        if(currentFile != null && !currentFile.IsEmpty) {
            FileData fileCopy = ObjectSpace.CreateObject<FileData>();
            using(var stream = new MemoryStream()) {
                currentFile.SaveToStream(stream);
                stream.Position = 0;
                fileCopy.LoadFromStream(currentFile.FileName, stream);
            }
            PortfolioFileData portfolio = ObjectSpace.CreateObject<PortfolioFileData>();
            portfolio.File = fileCopy;
            ViewCurrentObject.Portfolio.Add(portfolio);
            ObjectSpace.CommitChanges();
        }
    }
}

VB.NET

Imports System.IO
Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.Actions
Imports DevExpress.Persistent.Base
Imports DevExpress.Persistent.BaseImpl
Imports MainDemo.Module.BusinessObjects

Public Class UpdatePortfolioController
    Inherits ObjectViewController(Of DetailView, [Resume])

    Public Sub New()
        Dim updatePortfolioAction As New SimpleAction(Me, "UpdatePortfolio", PredefinedCategory.Edit)
        updatePortfolioAction.SelectionDependencyType = SelectionDependencyType.RequireSingleObject
        AddHandler updatePortfolioAction.Execute, AddressOf updatePortfolioAction_Execute
    End Sub
    Private Sub updatePortfolioAction_Execute(ByVal sender As Object, ByVal e As SimpleActionExecuteEventArgs)
        Dim currentFile As FileData = ViewCurrentObject.File
        If currentFile IsNot Nothing AndAlso Not currentFile.IsEmpty Then
            Dim fileCopy As FileData = ObjectSpace.CreateObject(Of FileData)()
            Using stream As MemoryStream = New MemoryStream()
                currentFile.SaveToStream(stream)
                stream.Position = 0
                fileCopy.LoadFromStream(currentFile.FileName, stream)
            End Using
            Dim portfolio As PortfolioFileData = ObjectSpace.CreateObject(Of PortfolioFileData)()
            portfolio.File = fileCopy
            ViewCurrentObject.Portfolio.Add(portfolio)
            ObjectSpace.CommitChanges()
        End If
    End Sub
End Class

Here, FileData is a built-in class that implements the IFileData interface.

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the LoadFromStream(String, Stream) method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

VB.NET

XAF_how-to-use-the-file-attachment-module-with-a-legacy-database-t237508/VB/CustomFileDataSolution.Module/BusinessObjects/InplaceFileData.vb#L40

End Property
Public Sub LoadFromStream(ByVal fileName As String, ByVal stream As Stream) Implements IFileData.LoadFromStream
    Guard.ArgumentNotNull(stream, "stream")