How to compile and upload to an Arduino from C# application

As datafiddler points out in his answer, you'll need to call avr-gcc first (in order to compile your program).

As an alternative for the second step (the upload process) you could use ArduinoSketchUploader, a native C# library to upload the binary HEX file to the Arduino through it's bootloader. This way, you don't have to ship / wrap avrdude with your code.

Disclaimer: this is a library I have personally written.

Once the nuget package ArduinoUploader is referenced, the resulting code would look like this:

var uploader = new ArduinoSketchUploader(
    new ArduinoSketchUploaderOptions()
    {
        FileName = @"C:\MyHexFiles\UnoHexFile.ino.hex",
        PortName = "COM3",
        ArduinoModel = ArduinoModel.UnoR3
    });
uploader.UploadSketch();

You do not upload C code, but you use avr-gcc to compile it to machine code. Additionally, the Arduino IDE does some preparation to produce a .cpp file from the .ino file (generate function prototypes, add include files) Then the utility avrdude is used to upload the resulting .hex file

Look at extended output while compiling and uploading.

In general it is possible, but the way you ask I doubt you will be successful. As you are working with c#, look for a VisualStudio plugin to compile and upload to an Arduino from within VisualStudio ( search for VisualMicro ). Perhaps that's interesting for you...

Code used to compile and install arduino in c# :

DosyaYolu is a arduino .ino folder path
`myPath` is a file path where arduinon is installed.

string myPath = @"C:\Program Files (x86)\Arduino\arduino"; 
System.Diagnostics.Process p = new System.Diagnostics.Process(); 
p.StartInfo.FileName = myPath;
p.StartInfo.Arguments = @"--upload " + DosyaYolu; 
p.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; 
p.StartInfo.CreateNoWindow = true; 
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.UseShellExecute = false;
p.Start();

You can download the Arduino software for non admin install as a folder and use this a resource for your C# program. Then you can just invoke the compiler in the background with the CMD properties set to cmd.StartInfo.WindowStyle = ProcessWindowStyle.Hidden; cmd.StartInfo.CreateNoWindow = true;

Then do the same for the uploader.

This way everything is being done automatically in the background without the user of the program noticing.