Hiding/Closing form is not working in C#

Question

I have login form and agent form in my application. The first scenario of my application is when the user login successfully all the credentials(server , username, password, status) will be save in text file and I already finish it. My second scenario is when the user close the agent form and open the application again, the application will read all the credential in text file and will be login automatically and I already finish it but my problem is when I open the application both form show the login and agent form where the expected result is only the agent form will display.

Here is my code for login form:

private void login_Load_1(object sender, EventArgs e)
        {
            Class.loginFunction logs = new Class.loginFunction();

            string isLogged, user, pass, server;
            try
            {

                isLogged = logs.readConfigFile(4);
                user = logs.readConfigFile(2);
                pass = logs.readConfigFile(3);
                server = logs.readConfigFile(1);

                if (isLogged.Equals("1"))
                {
                    logs.loginAuthentication(user, pass);
                }
                else
                {
                    txtServer.Text = server;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Exception Thrown: " + ex.Message);
            }


        }

Here is the code for the method of login:

public void loginAuthentication(string agentId, string pass)
        {
            login idx = new login();
            WebServiceInfo webInfo = new WebServiceInfo();
            LoginInfo logInfo = new LoginInfo();
            eDataNewUi eNewUi = new eDataNewUi();
            try
            {
                logInfo.serverAddress = readConfigFile(1);
                webInfo.url = "http://" + logInfo.serverAddress + "/eDataTran/service/main/agentLogin"; // store Url Of service in string
                webInfo.jsonData = "{\"agentId\":\"" + agentId + "\" ,\"password\":\"" + pass + "\"}";

                // Convert our JSON in into bytes using ascii encoding
                ASCIIEncoding encoding = new ASCIIEncoding();
                byte[] data = encoding.GetBytes(webInfo.jsonData);

                //  HttpWebRequest 
                HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(webInfo.url);
                webrequest.Method = "POST";
                webrequest.ContentType = "application/json";
                webrequest.ContentLength = data.Length;

                //  Get stream data out of webrequest object
                Stream newStream = webrequest.GetRequestStream();
                newStream.Write(data, 0, data.Length);
                newStream.Close();

                //  Declare & read the response from service
                HttpWebResponse webresponse = (HttpWebResponse)webrequest.GetResponse();

                // Fetch the response from the POST web service
                Encoding enc = System.Text.Encoding.GetEncoding("utf-8");
                StreamReader loResponseStream = new StreamReader(webresponse.GetResponseStream(), enc);
                string result = loResponseStream.ReadToEnd();
                loResponseStream.Close();

                JObject o = JObject.Parse(result);
                string responseCode = o["Data"][0]["ResponseCode"].ToString(); 

                switch (responseCode)
                {
                    case "0":
                        MessageBox.Show("Username and Password is not valid");
                        break;
                    case "1":
                        idx.Hide(); // this part where the form is not hiding
                        eNewUi.Show();
                        eNewUi.tssUserId.Text = "User Id: " + agentId;
                        getAgentId(agentId);
                        break;
                }

                webresponse.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Exception Response: " + ex.Message);
            }


        }

Here is my program.cs

 static Mutex mutex = new Mutex(false, "oreilly.com OneAtATimeDemo");
        [STAThread]
        static void Main()
        {
            if (!mutex.WaitOne(TimeSpan.FromSeconds(5), false))
            {
                MessageBox.Show("Application is running already!");
                return;
            }

            try
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new login());
            }
            finally
            {
                mutex.ReleaseMutex();
            }  

        }

Answer 1

You have not mentioned anything about the Program.cs but I have seen some similar problems so I will just assume the contents is similar to the following

 private static void Main() {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Login());
    }

Application already creates a Login object for you and in method loginAuthentication

public void loginAuthentication(string agentId, string pass){
    login idx = new login();//Here you created another Login object
....
}

As far as I am concerned your program successfully comes to case "1":

switch (responseCode) {
    case "0":
        MessageBox.Show("Username and Password is not valid");
        break;
    case "1":
        //This is the part where you are trying to hide a form, which is not even shown         
        idx.Hide(); 

Suggested Main:

private static void Main() {
    Application.EnableVisualStyles();
    Application.SetCompatibleTextRenderingDefault(false);
    var hasCredentialFile = CheckCredentialFile();        
    Application.Run(hasCredentialFile ? new Agent():Login());
}

Answer 2

As per info of the scenarios, you would be needing to check if the Textfile is generated. You should add a checking method on your Program.cs if this TextFile was generated else your application would fire the LoginFrm

Sample Code:

static class Program
{
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        if(TextFileChecker())
        {
             Application.Run(new AgentFrm());
        }
        else
        {
             Application.Run(new LoginFrm());
        }
    }

        private bool TextFileChecker()
        {
             //run a checking method for the textfile
        }
}