[C#]Richiamare form su altro files

[Luc@s]

Ho sto cod:

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using SiteManagerUtil;

namespace Site_Manager
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Princ : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Button btInsert;
		private System.Windows.Forms.Button btCancella;
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Princ()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.btInsert = new System.Windows.Forms.Button();
			this.btCancella = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// btInsert
			// 
			this.btInsert.Location = new System.Drawing.Point(32, 8);
			this.btInsert.Name = "btInsert";
			this.btInsert.Size = new System.Drawing.Size(104, 24);
			this.btInsert.TabIndex = 5;
			this.btInsert.Text = "Inserisci";
			this.btInsert.Click += new System.EventHandler(this.btInsert_Click);
			// 
			// btCancella
			// 
			this.btCancella.Location = new System.Drawing.Point(32, 48);
			this.btCancella.Name = "btCancella";
			this.btCancella.Size = new System.Drawing.Size(104, 24);
			this.btCancella.TabIndex = 6;
			this.btCancella.Text = "Cancella";
			// 
			// Princ
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(160, 85);
			this.Controls.AddRange(new System.Windows.Forms.Control[] {
																		  this.btCancella,
																		  this.btInsert});
			this.Name = "Princ";
			this.Text = "SiteManager";
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Princ());
		}

		private void btInsert_Click(object sender, System.EventArgs e)
		{
			Site_Manager.Insert inserisci = new Site_Manager.Insert();//Richiamo il form esterno
		}
	}
}

il files esterno è:

 
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace Site_Manager
{
	/// <summary>
	/// Summary description for Insert.
	/// </summary>
	public class Insert : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Label blTitolo;
		private System.Windows.Forms.Label lbIndirizzo;
		private System.Windows.Forms.TextBox txtTitolo;
		private System.Windows.Forms.TextBox txtIndirizzo;
		private System.Windows.Forms.Button btInsert;
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Insert()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
			Application.Run();
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.blTitolo = new System.Windows.Forms.Label();
			this.lbIndirizzo = new System.Windows.Forms.Label();
			this.txtTitolo = new System.Windows.Forms.TextBox();
			this.txtIndirizzo = new System.Windows.Forms.TextBox();
			this.btInsert = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// blTitolo
			// 
			this.blTitolo.Location = new System.Drawing.Point(24, 16);
			this.blTitolo.Name = "blTitolo";
			this.blTitolo.Size = new System.Drawing.Size(56, 24);
			this.blTitolo.TabIndex = 0;
			this.blTitolo.Text = "Titolo";
			// 
			// lbIndirizzo
			// 
			this.lbIndirizzo.Location = new System.Drawing.Point(16, 48);
			this.lbIndirizzo.Name = "lbIndirizzo";
			this.lbIndirizzo.Size = new System.Drawing.Size(64, 24);
			this.lbIndirizzo.TabIndex = 1;
			this.lbIndirizzo.Text = "Indirizzo";
			// 
			// txtTitolo
			// 
			this.txtTitolo.Location = new System.Drawing.Point(72, 16);
			this.txtTitolo.Name = "txtTitolo";
			this.txtTitolo.Size = new System.Drawing.Size(120, 20);
			this.txtTitolo.TabIndex = 2;
			this.txtTitolo.Text = "";
			// 
			// txtIndirizzo
			// 
			this.txtIndirizzo.Location = new System.Drawing.Point(72, 48);
			this.txtIndirizzo.Name = "txtIndirizzo";
			this.txtIndirizzo.Size = new System.Drawing.Size(120, 20);
			this.txtIndirizzo.TabIndex = 3;
			this.txtIndirizzo.Text = "";
			// 
			// btInsert
			// 
			this.btInsert.Location = new System.Drawing.Point(72, 88);
			this.btInsert.Name = "btInsert";
			this.btInsert.TabIndex = 4;
			this.btInsert.Text = "Inserisci";
			// 
			// Insert
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(208, 125);
			this.Controls.AddRange(new System.Windows.Forms.Control[] {
																		  this.btInsert,
																		  this.txtIndirizzo,
																		  this.txtTitolo,
																		  this.lbIndirizzo,
																		  this.blTitolo});
			this.Name = "Insert";
			this.Text = "Inserisci Sito";
			this.ResumeLayout(false);

		}
		#endregion
	}
	
}

Come richiamo sto form?

[Luc@s]

libreria esterna:

using System;
using System.Collections;
using SiteManagerUtil;

namespace SiteManagerUtil
{
	/// <summary>
	/// La classe principale
	/// </summary>
	public class SitMan 
	{
		/// <summary>
		/// Le Variabili publiche
		/// </summary>
		public System.Collections.ArrayList nome;// il nome
		public System.Collections.ArrayList indirizzo;// l'indirizzo
		public const string fine = "http://";
		/// <summary>
		/// Valida l'url controllando se comincia per http:// altri menti lo appende
		/// </summary>
		/// <param name="url">L'url da validare</param>
		/// <returns>L'url appeso</returns>
		public string validaUrl(string url)
		{
			if(!url.StartsWith("http://"))
			{
				url = url + fine;
			}
			return url;
		}
		/// <summary>
		/// La funzione che aggiunge un sito
		/// </summary>
		/// <param name="nm">Il nome del sito</param>
		/// <param name="indir">L'indirizzo del sito</param>
		/// <returns></returns>
		public string aggiungi(string nm, string indir)
		{
			this.nome.Add(nm);
			this.indirizzo.Add(indir);
			return "";
		}
		/// <summary>
		/// La funzione che cancella un sito
		/// </summary>
		/// <param name="nm">Il nome del sito</param>
		/// <param name="indir">L'indirizzo del sito</param>
		/// <returns></returns>
		public string cancella(string nm, string indir)
		{
			this.nome.Remove(nm);
			this.indirizzo.Remove(indir);
			return "";
		}
	}//Fine SitMan

}//Fine Namespace

[Luc@s]

[Luc@s]

ho risolto con la proprietà .Visible settata a true