C# Assign a Form to a variable

Question

I’m having a hard time solving this problem.

I created a project in Windows Form to open the other forms inside a panel, being that I would like to associate the Forms to be opened in the variavies at the beginning of the code, maybe I have to refer to this Forms several times during the code, I would like to declare them only once in a variable to use the variable instead of the Forms in the Click of the Buttons but I could not.

    Form Formulario1;// Gostaria de colocar o Form a ser aberto aqui e utilizar aenas a variavel
    Form Formulario2;// Gostaria de colocar o Form a ser aberto aqui e utilizar aenas a variavel
    Form Formulario3;// Gostaria de colocar o Form a ser aberto aqui e utilizar aenas a variavel
    Form Formulario4;// Gostaria de colocar o Form a ser aberto aqui e utilizar aenas a variavel

    private void Abrir_Formulario<MiForm>() where MiForm : Form, new()
    {
        Form formulario;
        formulario = panel_Formularios.Controls.OfType<MiForm>().FirstOrDefault();
        if (formulario == null)
        {
            formulario = new MiForm();
            formulario.SuspendLayout();
            formulario.TopLevel = false;
            formulario.FormBorderStyle = FormBorderStyle.None;
            formulario.Dock = DockStyle.Fill;
            panel_Formularios.Controls.Add(formulario);
            panel_Formularios.Tag = formulario;
            formulario.Show();
            formulario.BringToFront();
            formulario.FormClosed += new FormClosedEventHandler(Fechar_Formulario);
            formulario.ResumeLayout();
        }
        else
        {
            formulario.BringToFront();
        }
    }

     // BOTÃO FORMULARIO 1
    private void button1_Click(object sender, EventArgs e)
    {
        Abrir_Formulario<Form1>();// Ideal esse Form vir da variavel no inicio 
    }

    // BOTÃO FORMULARIO 2
    private void button2_Click(object sender, EventArgs e)
    {
        Abrir_Formulario<Form2>(); // Ideal esse Form vir da variavel no inicio 
    }

    // BOTÃO FORMULARIO 3
    private void button3_Click(object sender, EventArgs e)
    {
        Abrir_Formulario<Form3>();// Ideal esse Form vir da variavel no inicio 
    }

    // BOTÃO FORMULARIO 4
    private void button4_Click(object sender, EventArgs e)
    {
        Abrir_Formulario<Form4>();// Ideal esse Form vir da variavel no inicio 
    }

Answer 1

Good morning, if I understand correctly try as follows first state this variable of the form example frmBuscareClients.

    private frmBuscarClientes BuscarClientes = null;
//aqui voce verifica se ja esta aberto, para nao fica abrindo varios formularios
    if (Application.OpenForms.OfType<frmBuscarClientes>().Count() > 0)
                    {
                        this.BuscarClientes.WindowState = FormWindowState.Normal;
                        //Aqui e caso esteja minimzado o formulario abra o mesmo ao invés de um novo
    
                    }
                    else
                    {
    
                        this.BuscarClientes = new frmBuscarClientes();
                        this.BuscarClientes.Text = "Buscar Clientes";//titulo do formulario
                        this.BuscarClientes.TopLevel = false;
                        
                        this.BuscarClientes.Visible = true;
                        this.BuscarClientes.FormBorderStyle = FormBorderStyle.Sizable;//borda
                        gbPrincipal.Controls.Add(BuscarClientes);//BuscarCliente é a variavel do fomulário
                        //gbPrincipal é o nome do painel
                    }

// try from there and I guarantee you’ll come up with something good. // only repeat the code for other forms.

can put in a function.