How to transfer the file from Windows Form Application to Xamarin Forms using USB cable C#.net

Question

I am now developing Android Application and the Windows Form.

In the previous, the users need to plug in with USB, copy the file and paste into android folder but it would be troublesome and takes time to do.

How can I transfer the file directly from the PC to android Folder (Internal Storage/ downloads) ?

I tried with FolderBrowserDialog to browse and copy into android but "OK" button is disabled when I point the location. enter image description here

Should I write it in Windows Form backend or Xamarin Forms backend side in order to direct transfer into the Android App?

I cannot use Web API as cannot use the internet connection.

FolderBrowserDialog dialog = new FolderBrowserDialog();
                
if (dialog.ShowDialog() == DialogResult.OK)
   {
         txtCopy.Text = dialog.SelectedPath;
   }
         string copyFileName = Path.Combine(txtCopy.Text, originalFile); //originalFile->FileName (testing.jpg)

         File.Copy(txtFile1.Text, copyFileName, true);

Direct file transfer from Windows Form and Xamarin Forms by clicking button

Answer 1

Based on your code, I made a Windows Form project to complete the copy.

You could refer to the following code:

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();
        }

        private void folderBrowserDialog1_HelpRequest(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog dialog = new FolderBrowserDialog();
            if (dialog.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = dialog.SelectedPath;
            }
            
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog dialog = new FolderBrowserDialog();
            dialog.ShowDialog();
            textBox2.Text = dialog.SelectedPath;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            DirectoryInfo thefolder = new DirectoryInfo(textBox1.Text);
            foreach (FileInfo nextfile in thefolder.GetFiles()) 
            {
                try
                {
                    string filename = nextfile.Name;
                    string filefullname = nextfile.FullName;
                    string mudi = textBox2.Text + "\" + filename;
                    if (File.Exists(mudi))
                    {
                        //File.Delete(mudi);
                    }
                    else
                    {
                        File.Copy(filefullname, mudi);
                        MessageBox.Show("Successful");
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
        }
    }
}

Answer 2

Now I got it. I have to download MediaDevices framework in NuGet Package Manager to download/ transfer the file from Android device to PC.

I can transfer the file from Android to PC.

But the thing is I cannot transfer/ Upload the file from PC to Android (when using PCToPDA()). When I run the program, the error Director "DT50Internal shared storageDownload" not found appear even though the directory path is correct.

Any idea why is that happening?

    string originalFile;

    private void BtnBrowse_Click(object sender, EventArgs e)
    {
        Browse();     //Get the files from Android Folder
    }

    private void Browse()
    {
        try
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                txtFile1.Text = openFileDialog1.FileName;

                string fileName = Path.GetDirectoryName(openFileDialog1.FileName);
                originalFile = Path.GetFileName(openFileDialog1.FileName);
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Browse-ERR", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

    private void BtnCopy_Click(object sender, EventArgs e)
    {
        PDAToPC();       //Android to PC
        //PCToPDA();       //PC to Android 
    }

    private void PDAToPC()
    {
        try
        {
            string DeviceNameAsSeenInMyComputer = "DT50";

            var devices = MediaDevice.GetDevices();

            using (var device = devices.Where(d => d.FriendlyName == DeviceNameAsSeenInMyComputer || d.Description == DeviceNameAsSeenInMyComputer).First())
            {
                device.Connect();
                var photoDir = device.GetDirectoryInfo(@"Internal shared storageDownload");
                var files = photoDir.EnumerateFiles("*.*", SearchOption.TopDirectoryOnly);

                
                foreach (var file in files)
                {
                    string destinationFileName = $@"D:KhineTheinTestingTransferTestingphoto{file.Name}";
                    if (!File.Exists(destinationFileName))
                    {
                        using (FileStream fs = new FileStream(destinationFileName, FileMode.Create, System.IO.FileAccess.Write))
                        {
                            device.DownloadFile(file.FullName, fs);
                            
                        }
                    }


                }
                device.Disconnect();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "PDAToPC-ERR", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

    private void PCToPDA()
    {
        try
        {
            string DeviceNameAsSeenInMyComputer = "DT50";
            string tempFileName = "CaptureImport.txt";
            var devices = MediaDevice.GetDevices();

            using (var device = devices.Where(d => d.FriendlyName == DeviceNameAsSeenInMyComputer || d.Description == DeviceNameAsSeenInMyComputer).First())
            {
                device.Connect();
                var photoDir = device.GetDirectoryInfo(@"Internal shared storageDownload");
                var files = photoDir.EnumerateFiles("*.*", SearchOption.TopDirectoryOnly);

                foreach (var file in files)
                {
                    string originalFileName = $@"D:KhineTheinTestingTransferTestingphoto{tempFileName}";

                    string transferToFileName = $@"{DeviceNameAsSeenInMyComputer}Internal shared storageDownload{tempFileName}";

                    using (FileStream fs = new FileStream(originalFileName, FileMode.Open, System.IO.FileAccess.Read))
                    {
                        //device.DownloadFile(file.FullName, fs);                       //Path, Stream
                        device.UploadFile(fs, transferToFileName);                      //Stream, Path
                    }


                }
                device.Disconnect();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "PCToPDA-ERR", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }