Develop Reference

Loading Tensorflow model in c#

I am really struggling with the fact that i don't know how can I load and use a TensorFlow image classifier model in c#.
To be more precise I want to use a model trained in Teachable Machine that can be exported in multiple TensorFlow formats.
And if possible an example code will be really helpful.
I have tried to ask the same question but it got closed, I really need to find out how can I load and use the model so please let the question open. Thanks a lot for the support.

If you need only to evaluate model in C# code, then you need some lightweight library that can be used as loader and evaluator for your network.
There are many good libraries to work with tensorflow models in C#, like:
TensorFlowSharp
TensorFlow.NET
Unfortunately, all existing libraries has pre-defined logic for training model too, so that is a little ballast for your task.
To accomplish your purposes, please see this detailed article about how to load TF model into your C# application using TensorFlowSharp.

I used TensorFlowSharpin the past, but that library is still stuck with TensorFlow 1.x, and development seems quite dead. Because of that, I moved on to ML.NET.
Please see this article about how to use ML.NET with C# (disclaimer: I was the author of that article). Below is the gist of it.
Convert saved_model to onnx
Install tf2onnx.
pip install tf2onnx
Use it to convert saved_model to onnx.
python -m tf2onnx.convert --saved-model <path to saved_model folder> --output "model.onnx"
Use ML.NET to make prediction
Install the necessary packages.
dotnet add package Microsoft.ML
dotnet add package Microsoft.ML.OnnxRuntime
dotnet add package Microsoft.ML.OnnxTransformer
Define the input and output model classes.
public class Input
{
[VectorType(<input size>)]
[ColumnName("<input node name>")]
public float[] Data { get; set; } // Remember to change the type if your model does not use float
}
public class Output
{
[VectorType(<output size>)]
[ColumnName("<output node name>")]
public float[] Data { get; set; } // Remember to change the type if your model does not use float
}
Load the model in onnx format.
using Microsoft.ML;
var modelPath = "<path to onnx model>";
var outputColumnNames = new[] { "<output name>" };
var inputColumnNames = new[] { "<input name>" };
var mlContext = new MLContext();
var pipeline = _mlContext.Transforms.ApplyOnnxModel(outputColumnNames, inputColumnNames, modelPath);
Make prediction
var input_data= ... // code to load input into an array
var input = new Input { Data = data };
var dataView = mlContext.Data.LoadFromEnumerable(new[] { input });
var transformedValues = pipeline.Fit(dataView).Transform(dataView);
var output = mlContext.Data.CreateEnumerable<Output>(transformedValues, reuseRowObject: false);
// code to use the result in output

C# code completion with NRefactory 5

I just found out about NRefactory 5 and I would guess, that it is the most suitable solution for my current problem. At the moment I'm developing a little C# scripting application for which I would like to provide code completion. Until recently I've done this using the "Roslyn" project from Microsoft. But as the latest update of this project requires .Net Framework 4.5 I can't use this any more as I would like the app to run under Win XP as well. So I have to switch to another technology here.
My problem is not the compilation stuff. This can be done, with some more effort, by .Net CodeDomProvider as well. The problem ist the code completion stuff. As far as I know, NRefactory 5 provides everything that is required to provide code completion (parser, type system etc.) but I just can't figure out how to use it. I took a look at SharpDevelop source code but they don't use NRefactory 5 for code completion there, they only use it as decompiler. As I couldn't find an example on how to use it for code completion in the net as well I thought that I might find some help here.
The situation is as follows. I have one single file containing the script code. Actually it is not even a file but a string which I get from the editor control (by the way: I'm using AvalonEdit for this. Great editor!) and some assemblies that needs to get referenced. So, no solution files, no project files etc. just one string of source code and the assemblies.
I've taken a look at the Demo that comes with NRefactory 5 and the article on code project and got up with something like this:
var unresolvedTypeSystem = syntaxTree.ToTypeSystem();
IProjectContent pc = new CSharpProjectContent();
// Add parsed files to the type system
pc = pc.AddOrUpdateFiles(unresolvedTypeSystem);
// Add referenced assemblies:
pc = pc.AddAssemblyReferences(new CecilLoader().LoadAssemblyFile(
System.Reflection.Assembly.GetAssembly(typeof(Object)).Location));
My problem is that I have no clue on how to go on. I'm not even sure if it is the right approach to accomplish my goal. How to use the CSharpCompletionEngine? What else is required? etc. You see there are many things that are very unclear at the moment and I hope you can bring some light into this.
Thank you all very much in advance!

I've just compiled and example project that does C# code completion with AvalonEdit and NRefactory.
It can be found on Github here.

Take a look at method ICSharpCode.NRefactory.CSharp.CodeCompletion.CreateEngine. You need to create an instance of CSharpCompletionEngine and pass in the correct document and the resolvers. I managed to get it working for CTRL+Space compltition scenario. However I am having troubles with references to types that are in other namespaces. It looks like CSharpTypeResolveContext does not take into account the using namespace statements - If I resolve the references with CSharpAstResolver, they are resolved OK, but I am unable to correctly use this resolver in code completition scenario...
UPDATE #1:
I've just managed to get the working by obtaining resolver from unresolved fail.
Here is the snippet:
var mb = new DefaultCompletionContextProvider(doc, unresolvedFile);
var resolver3 = unresolvedFile.GetResolver(cmp, loc); // get the resolver from unresolvedFile
var engine = new CSharpCompletionEngine(doc, mb, new CodeCompletionBugTests.TestFactory(resolver3), pctx, resolver3.CurrentTypeResolveContext );
Update #2:
Here is the complete method. It references classes from unit test projects, sou you would need to reference/copy them into your project:
public static IEnumerable<ICompletionData> DoCodeComplete(string editorText, int offset) // not the best way to put in the whole string every time
{
var doc = new ReadOnlyDocument(editorText);
var location = doc.GetLocation(offset);
string parsedText = editorText; // TODO: Why there are different values in test cases?
var syntaxTree = new CSharpParser().Parse(parsedText, "program.cs");
syntaxTree.Freeze();
var unresolvedFile = syntaxTree.ToTypeSystem();
var mb = new DefaultCompletionContextProvider(doc, unresolvedFile);
IProjectContent pctx = new CSharpProjectContent();
var refs = new List<IUnresolvedAssembly> { mscorlib.Value, systemCore.Value, systemAssembly.Value};
pctx = pctx.AddAssemblyReferences(refs);
pctx = pctx.AddOrUpdateFiles(unresolvedFile);
var cmp = pctx.CreateCompilation();
var resolver3 = unresolvedFile.GetResolver(cmp, location);
var engine = new CSharpCompletionEngine(doc, mb, new CodeCompletionBugTests.TestFactory(resolver3), pctx, resolver3.CurrentTypeResolveContext );
engine.EolMarker = Environment.NewLine;
engine.FormattingPolicy = FormattingOptionsFactory.CreateMono();
var data = engine.GetCompletionData(offset, controlSpace: false);
return data;
}
}
Hope it helps,
Matra

NRefactory 5 is being used in SharpDevelop 5. The source code for SharpDevelop 5 is currently available in the newNR branch on github. I would take a look at the CSharpCompletionBinding class which has code to display a completion list window using information from NRefactory's CSharpCompletionEngine.

EzAPI OLE DB Destination

I've searched all over and I now have to ask SO. I'm trying to construct a simple dataflow using EzAPI. It's been anything but easy, but I'm committed to figuring this out. What I can't figure out is how to get the EzOleDBDestination working. Here's my complete code
var a = new Application();
// using a template since it's impossible to set up an ADO.NET connection to MySQL
// using EzAPI and potentially even with the raw SSIS API...
var pkg = new EzPackage(a.LoadPackage(#"C:\...\Package.dtsx", null));
pkg.Name = "Star";
var df = new EzDataFlow(pkg);
df.Name = "My DataFlow";
var src = new EzAdoNetSource(df);
src.Name = "Source Database";
src.SqlCommand = "SELECT * FROM enum_institution";
src.AccessMode = AccessMode.AM_SQLCOMMAND;
src.Connection = new EzConnectionManager(pkg, pkg.Connections["SourceDB"]);
src.ReinitializeMetaData();
var derived = new EzDerivedColumn(df);
derived.AttachTo(src);
derived.Name = "Prepare Dimension Attributes";
derived.LinkAllInputsToOutputs();
derived.Expression["SourceNumber"] = "id";
derived.Expression["Name"] = "(DT_STR,255,1252)description";
// EDIT: reordered the operation here and I no longer get an error, but
// I'm not getting any mappings or any input columns when I open the package in the designer
var dest = new EzOleDbDestination(df);
dest.AttachTo(derived, 0, 0);
dest.Name = "Target Database";
dest.AccessMode = 0;
dest.Table = "[dbo].[DimInstitution]";
dest.Connection = new EzConnectionManager(pkg, pkg.Connections["TargetDB"]);
// this comes from Yahia's link
var destInput = dest.Meta.InputCollection[0];
var destVirInput = destInput.GetVirtualInput();
var destInputCols = destInput.InputColumnCollection;
var destExtCols = destInput.ExternalMetadataColumnCollection;
var sourceColumns = derived.Meta.OutputCollection[0].OutputColumnCollection;
foreach(IDTSOutputColumn100 outputCol in sourceColumns) {
// Now getting COM Exception here...
var extCol = destExtCols[outputCol.Name];
if(extCol != null) {
// Create an input column from an output col of previous component.
destVirInput.SetUsageType(outputCol.ID, DTSUsageType.UT_READONLY);
var inputCol = destInputCols.GetInputColumnByLineageID(outputCol.ID);
if(inputCol != null) {
// map the input column with an external metadata column
dest.Comp.MapInputColumn(destInput.ID, inputCol.ID, extCol.ID);
}
}
}
Basically, anything that involves calls to ReinitializeMetadata() results in 0xC0090001, because that method is where the error happens. There's no real documentation to help me, so I have to rely on any gurus here.
I should mention that the source DB is MySQL and the target DB is SQL Server. Building packages like this using the SSIS designer works fine, so I know it's possible.
Feel free to tell me if I'm doing anything else wrong.
EDIT: here's a link to the base package I'm using as a template: http://www.filedropper.com/package_1 . I've redacted the connection details, but any MySQL and SQL Server database will do. The package will read from MySQL (using the MySQL ADO.NET Connector) and write to SQL Server.
The database schema is mostly irrelevant. For testing, just make a table in MySQL that has two columns: id (int) and description (varchar), with id being the primary key. Make equivalent columns in SQL Server. The goal here is simply to copy from one to the other. It may end up being more complex at some point, but I have to get past this hurdle first.

I can't test this now BUT I am rather sure that the following will help you get it working:
Calling ReinitializeMetadata() causes the component to fetch the table metadata. This should only be called after setting the AccessMode and related property. You are calling it before setting AccessMode...
Various samples including advice on debugging problems
define the derived column(s) directly in the SQL command instead of using a EzDerivedColumn
try to get it working with 2 SQL Server DBs first, some of the available MySQL ADO.NET provider have some shortcomings under some circumstances
UPDATE - as per comments some more information on debugging this and a link to a complete end-to-end sample with source:
http://blogs.msdn.com/b/mattm/archive/2009/08/03/looking-up-ssis-hresult-comexception-errorcode.aspx
http://blogs.msdn.com/b/mattm/archive/2009/08/03/debugging-a-comexception-during-package-generation.aspx
Complete working sample with source

I've had this exact same issue and been able to resolve it with a lot of experimentation. In short you must set the connection for both the source and destination, and then call the attachTo after both connections are set. You must call attachTo for every component.
I've written a blog about starting with an SSIS package as a template, and then manipulating it programmatically to produce a set of new packages.
The article explains the issue more.

Retrieve data from browser local storage using c#

Is it possible to retrieve data from chrome/firefox local storage using C#?

Disclaimer: I have tested this on my Windows 7 x64 running Google Chrome 13.0.782.220 at the moment. The information provided here is a result of my own research and is not any official way or API to retrieve this information. Use at your own risk. Also the technique presented here might break with any future release if Chrome changes the way to store this information.
So, Google Chrome uses SQLite to persist local storage data. You could use the System.Data.SQLite managed driver to read it from your .NET application. If you are running on Windows 7 (don't know for others as that's the one I have and can test), you will have the following folder:
c:\Users\SOMEUSERNAME\AppData\Local\Google\Chrome\User Data\Default\Local Storage\
This folder will contain multiple files with the .localstorage extension. Each file is for different site. For example for StackOverflow I have http_stackoverflow.com_0.localstorage but of course this naming is totally arbitrary and you cannot rely upon it. Each file represents a SQLite database.
I have noticed that this database contains a table called ItemTable with 2 string columns called key and value.
So to read the values it's a simple matter of sending a SQL query:
class Program
{
static void Main()
{
using (var conn = new SQLiteConnection("Data Source=http_stackoverflow.com_0.localstorage;Version=3;"))
using (var cmd = conn.CreateCommand())
{
conn.Open();
cmd.CommandText = "SELECT key, value FROM ItemTable";
using (var reader = cmd.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(
"key: {0}, value: {1}",
reader.GetString(reader.GetOrdinal("key")),
reader.GetString(reader.GetOrdinal("value"))
);
}
}
}
}
}

When using Chromium Embedded Framework I found that the above solution has many limitations. It seems like Chromium have moved to using leveldb instead.
I ended up with a solution where I inject JS code that modify local storage in FrameLoadStart. (it should be easy to read values as well - JavascriptResponse.Result can be casted to a IDictionary when using this script: "window.localStorage;" instead)
// writing local storage in FrameLoadStart
foreach (var entry in LocalStorage)
{
script += $"window.localStorage.{entry.Key} = '{entry.Value}';";
}
IFrame frame = chromeBrowser.GetMainFrame();
var result = await frame.EvaluateScriptAsync(script , frame.Url, 0);
if(!result.Success)
{
throw new Exception(result.Message);
}

Display a ConnectionString dialog

I'm trying to create a program in C# that should be able to create, backup and restore a SQL Server database.
For this, the user needs to be able to setup a connection string to the desired SQL Server (and database).
I would like to use the same dialog as for example Visual Studio for creating the connection string.
Is this possible?

The data connection dialog component linked to in this answer is no longer available for download.
However, a (apparently somewhat altered) DataConnectionDialog component has since become available on NuGet.
Installation:
Add the component to your Visual Studio project via the NuGet package manager console:
Install-Package DataConnectionDialog
Usage example:
// using Microsoft.Data.ConnectionUI;
// using System.Windows.Forms;
bool TryGetDataConnectionStringFromUser(out string outConnectionString)
{
using (var dialog = new DataConnectionDialog())
{
// If you want the user to select from any of the available data sources, do this:
DataSource.AddStandardDataSources(dialog);
// OR, if you want only certain data sources to be available
// (e.g. only SQL Server), do something like this instead:
dialog.DataSources.Add(DataSource.SqlDataSource);
dialog.DataSources.Add(DataSource.SqlFileDataSource);
…
// The way how you show the dialog is somewhat unorthodox; `dialog.ShowDialog()`
// would throw a `NotSupportedException`. Do it this way instead:
DialogResult userChoice = DataConnectionDialog.Show(dialog);
// Return the resulting connection string if a connection was selected:
if (userChoice == DialogResult.OK)
{
outConnectionString = dialog.ConnectionString;
return true;
}
else
{
outConnectionString = null;
return false;
}
}
}

Note: The dialog component referred to below is no longer available for download. Unless you have retrieved it in the past, you will probably not get this answer's sample code to work.
Alternative: There is now a different DataConnectionDialog available on
NuGet. See this answer for details.
"Data Connection Dialog" on MSDN Archive Gallery (broken as of 1 Sept. 2015)
The data connection dialog is a database tool component released with Visual Studio. It allows users to build connection strings and to connect to specific data sources. try this..
C# Sample:
static void Main(string[] args)
{
DataConnectionDialog dcd = new DataConnectionDialog();
DataConnectionConfiguration dcs = new DataConnectionConfiguration(null);
dcs.LoadConfiguration(dcd);
if (DataConnectionDialog.Show(dcd) == DialogResult.OK)
{
// load tables
using (SqlConnection connection = new SqlConnection(dcd.ConnectionString))
{
connection.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM sys.Tables", connection);
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(reader.HasRows);
}
}
}
}
dcs.SaveConfiguration(dcd);
}
Here source code also available. we can integrate and redistribute the source code with our application according to license.

Yes and no.
Yes, it is technically possible, but I urge you not to; that dialog is part of Visual Studio and is lot listed in "redist". My interpretation is that you are not free to redistribute this dll.

I think all the other answers here are out-of-date, but I found a current solution at code.msdn.microsoft.com:
Using Microsoft Visual Studio Connection Dialog at runtime
In Visual Studio when a developer wants to create strong typed classes for database tables either for the conventional TableAdapter or Entity Framework there is a place in the process where a dialog is displayed as shown below. I will show you how to do this at runtime and a bit more.
The download is a solution that builds the following dlls:
Microsoft.Data.ConnectionUI.Dialog.dll
Microsoft.Data.ConnectionUI.dll
Microsoft.Data.DataConnectionConfiguration.dll
The solution also contains a sample application showing how to use them.
Worked a treat for me and it is super easy.

You can use UDL file.
Configuring Data Controls to Use Universal Data Link (.udl) Files

You can use SQLConnectionStringUI Nuget package.

I created some code that will do this. The code is in GitHub and you can learn about it here: https://csharpdeveloper.wordpress.com/2020/05/07/a-c-net-dialog-for-connecting-to-sql-server/
Lin

Create your own form similar to Server Explorer Connection Setting window, and implement it. You cannot use that form meant for VS