Net users,
How can I persist an instance of the PartialLeastSquaresAnalysis class? Other classes (e.g. KernelSupportVectorMachine) have a Save method so that we can persist the object to the disk. Since PartialLeastSquaresAnalysis does not have a Save method, is there another way to persist this classs?
Thanks for your help.
Charles
The save and load methods found in the framework are just convenience methods for the standard .NET binary serialization. If those methods are not available for a particular class, you should still be able to save it using:
PartialLeastSquaresAnalysis analysis = ...
using (FileStream fs = new FileStream(path, FileMode.Create))
{
var fmt = new BinaryFormatter();
fmt.Serialize(fs, analysis);
}
and you should be able to load it back using
PartialLeastSquaresAnalysis analysis = null;
using (FileStream fs = new FileStream(path, FileMode.Open))
{
var fmt = new BinaryFormatter();
analysis = (PartialLeastSquaresAnalysis)fmt.Deserialize(fs);
}
Related
I have a .NET Core API that I'd like to extend to save uploaded images asynchronously.
Using ImageSharp I should be able to check uploads and resize if predefined size limits are exceeded. However I can't get a simple async save working.
A simple (non-async) save to file works without problem:
My Controller extracts IFormFile from the upload and calls the following method without any problem
public static void Save(IFormFile image, string imagesFolder)
{
var fileName = Path.Combine(imagesFolder, image.FileName);
using (var stream = image.OpenReadStream())
using (var imgIS = Image.Load(stream, out IImageFormat format))
{
imgIS.Save(fileName);
}
}
ImageSharp is currently lacking async methods so a workaround is necessary.
The updated code below saves the uploaded file but the format is incorrect - when viewing the file I get the message "It appears we don't support this file format".
The format is extracted from the ImageSharp Load method. and used when saving to MemoryStream.
MemoryStream CopyToAsync method is used to save to FileStream to make the upload asynchronous.
public static async void Save(IFormFile image, string imagesFolder)
{
var fileName = Path.Combine(imagesFolder, image.FileName);
using (var stream = image.OpenReadStream())
using (var imgIS = Image.Load(stream, out IImageFormat format))
using (var memoryStream = new MemoryStream())
using (var fileStream = new FileStream(fileName, FileMode.OpenOrCreate))
{
imgIS.Save(memoryStream, format);
await memoryStream.CopyToAsync(fileStream).ConfigureAwait(false);
fileStream.Flush();
memoryStream.Close();
fileStream.Close();
}
}
I can't work out whether the issue is with ImageSharp Save to MemoryStream, or the MemoryStream.CopyToAsync.
I'm currently getting 404 on SixLabors docs - hopefully not an indication that the project has folded.
How can I make the upload async and save to file in the correct format?
CopyToAsync copies a stream starting at its current position. You must change the current position of memoryStream back to start before copying:
// ...
memoryStream.Seek(0, SeekOrigin.Begin);
await memoryStream.CopyToAsync(fileStream).ConfigureAwait(false);
// ...
The ADLS .NET SDK has some good examples for reading and creating text files. This uses StreamReader and this shouldn't be used with binary files. I tried using BinaryReader but have been unsuccessful.
https://learn.microsoft.com/en-us/azure/data-lake-store/data-lake-store-data-operations-net-sdk
//Read file contents
using (var readStream = new StreamReader(client.GetReadStream(fileName)))
{
string line;
while ((line = readStream.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
Can the .NET SDK create/read binary? If so, are there any examples of doing this?
Can the .NET SDK create/read binary? If so, are there any examples of doing this?
Short answer is yes, please refer to the following demo code.
Create binary File
AdlsClient adlsClient = AdlsClient.CreateClient($"{datalakeAccount}.azuredatalakestore.net", clientCreds);
using (var stream = adlsClient.CreateFile("file name", IfExists.Overwrite))
{
byte[] textByteArray = File.ReadAllBytes(#"local file path");
stream.Write(textByteArray, 0, textByteArray.Length);
}
read binary file and write to local file
using (var filesream = adlsClient.GetReadStream("1.png"))
{
MemoryStream memorystream = new MemoryStream();
filesream.CopyTo(memorystream);
memorystream.Position = 0;
File.WriteAllBytes(#"filename", memorystream.ToArray());
}
I got an assignment to see if I can make power app that will generate some PDF file for end user to see.
After through research on this topic I found out that this is not an easy to achieve :)
In order to make power app generate and download/show generated pdf I made these steps:
Created power app with just one button :) to call Azure function from step 2
Created Azure function that will generate and return pdf as StreamContent
Due to power app limitations (or I just could not find the way) there was no way for me to get pdf from response inside power app.
After this, I changed my Azure function to create new blob entry but know I have problem to get URL for that new entry inside Azure function in order to return this to power app and then use inside power app Download function
My Azure function code is below
using System;
using System.Net;
using System.Net.Http.Headers;
using System.Runtime.InteropServices;
using Aspose.Words;
public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log, Stream outputBlob)
{
log.Info($"C# HTTP trigger function processed a request. RequestUri={req.RequestUri}");
var dataDir = #"D:/home";
var docFile = $"{dataDir}/word-templates/WordAutomationTest.docx";
var uid = Guid.NewGuid().ToString().Replace("-", "");
var pdfFile = $"{dataDir}/pdf-export/WordAutomationTest_{uid}.pdf";
var doc = new Document(docFile);
doc.Save(pdfFile);
var result = new HttpResponseMessage(HttpStatusCode.OK);
var stream = new FileStream(pdfFile, FileMode.Open);
stream.CopyTo(outputBlob);
// result.Content = new StreamContent(stream);
// result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
// result.Content.Headers.ContentDisposition.FileName = Path.GetFileName(pdfFile);
// result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
// result.Content.Headers.ContentLength = stream.Length;
return result;
}
I left old code (the one that streams pdf back under comments just as reference of what I tried)
Is there any way to get download URL for newly generated blob entry inside Azure function?
Is there any better way to make power app generate and download/show generated PDF?
P.S. I tried to use PDFViewer control inside power app, but this control is completely useless cause U can not set Document value via function
EDIT: Response from #mathewc helped me a lot to finally wrap this up. All details are below.
New Azure function that works as expected
#r "Microsoft.WindowsAzure.Storage"
using System;
using System.Net;
using System.Net.Http.Headers;
using System.Runtime.InteropServices;
using Aspose.Words;
using Microsoft.WindowsAzure.Storage.Blob;
public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log, CloudBlockBlob outputBlob)
{
log.Info($"C# HTTP trigger function processed a request. RequestUri={req.RequestUri}");
var dataDir = #"D:/home";
var docFile = $"{dataDir}/word-templates/WordAutomationTest.docx";
var uid = Guid.NewGuid().ToString().Replace("-", "");
var pdfFile = $"{dataDir}/pdf-export/WordAutomationTest_{uid}.pdf";
var doc = new Document(docFile);
doc.Save(pdfFile);
var result = new HttpResponseMessage(HttpStatusCode.OK);
var stream = new FileStream(pdfFile, FileMode.Open);
outputBlob.UploadFromStream(stream);
return req.CreateResponse(HttpStatusCode.OK, outputBlob.Uri);
}
REMARKS:
Wee need to add "WindowsAzure.Storage" : "7.2.1" inside project.json. This package MUST be the same version as one with same name that is in %USERPROFILE%\AppData\Local\Azure.Functions.Cli
If you change your blob output binding type from Stream to CloudBlockBlob you will have access to CloudBlockBlob.Uri which is the blob path you require (documentation here). You can then return that Uri back to your Power App. You can use CloudBlockBlob.UploadFromStreamAsync to upload your PDF Stream to the blob.
Quick search here yielded nothing. So, I have started using some rather roundabout ways to use StreamWriter in my WinRT Application. Reading works well, writing works differently. What' I'm seeing is that when I select my file to write, if I choose a new file then no problem. The file is created as I expect. If I choose to overwrite a file, then the file is overwritten to a point, but the point where the stream stops writing, if the original file was large, then the old contents exist past where my new stream writes.
The code is as such:
public async void WriteFile(StorageFile selectedFileToSave)
{
// At this point, selectedFileToSave is from the Save File picker so can be a enw or existing file
StreamWriter writeStream;
Encoding enc = new UTF8Encoding();
Stream dotNetStream;
dotNetStream = await selectedFileToSave.OpenStreamForWriteAsync();
StreamWriter writeStream = new StreamWriter(dotNetStream, enc);
// Do writing here
// Close
writeStream.Write(Environment.NewLine);
await writeStream.FlushAsync();
await dotNetStream.FlushAsync();
}
Can anyone offer clues on what I could be missing? There are lots of functions missing in WinRT, so not really following ways to get around this
Alternatively you can set length of the stream to 0 with SetLength method before using StreamWriter:
var stream = await file.OpenStreamForWriteAsync();
stream.SetLength(0);
using (var writer = new StreamWriter(stream))
{
writer.Write(text);
}
Why not just use the helper methods in FileIO class? You could call:
FileIO.WriteTextAsync(selectedFileToSave, newTextContents);
If you really need a StreamWriter, first truncate the file by calling
FileIO.WriteBytesAsync(selectedFileToSave, new byte[0]);
And then continue with your existing code.
I am using the Kinect Toolbox, so I have a list of ReplaySkeletonFrames in my hand.
I am iterating over this list, getting the first tracked skeleton and modifying some properties.
As we know, when we change an object we also change the original object.
I need to make a copy of an skeleton.
Note: I can't use CopySkeletonDataTo() because my frame is a ReplaySkeletonFrame and not the ReplayFrame of the "normal" Kinect.
I tried to make my own method that copies property by property, but some properties could not be copied. look...
public static Skeleton Clone(this Skeleton actualSkeleton)
{
if (actualSkeleton != null)
{
Skeleton newOne = new Skeleton();
// doesn't work - The property or indexer 'Microsoft.Kinect.SkeletonJoints'
// cannot be used in this context because the set accessor is inaccessible
newOne.Joints = actualSkeleton.Joints;
// doesn't work - The property or indexer 'Microsoft.Kinect.SkeletonJoints'
// cannot be used in this context because the set accessor is inaccessible
JointCollection jc = new JointCollection();
jc = actualSkeleton.Joints;
newOne.Joints = jc;
//...
}
return newOne;
}
How to solve it?
with more search i ended up whit the following solution: Serialize the skeleton to the memory, deserialize to a new object
Here is the code
public static Skeleton Clone(this Skeleton skOrigin)
{
// isso serializa o skeleton para a memoria e recupera novamente, fazendo uma cópia do objeto
MemoryStream ms = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ms, skOrigin);
ms.Position = 0;
object obj = bf.Deserialize(ms);
ms.Close();
return obj as Skeleton;
}