Csharp/C Sharp by API/System.Windows.Forms/MessageBox

MessageBox.Show

 

using System.Windows.Forms;
   
class TwoForms
{
     public static void Main()
     {
          Form form1 = new Form();
          Form form2 = new Form();
   
          form1.Text = "Form passed to Run()";
          form2.Text = "Second form";
          form2.Show();
   
          Application.Run(form1);
   
          MessageBox.Show("Application.Run() has returned control back to Main.","TwoForms");
     }
}

MessageBox.Show(String, String);

 
using System;
using System.Windows.Forms;
class MainForm : Form
{
    private Label label1;
    private TextBox textBox1;
    private Button button1;
    public MainForm()
    {
         this.label1 = new Label();
         this.textBox1 = new TextBox();
         this.button1 = new Button();
         this.SuspendLayout();
         this.label1.Location = new System.Drawing.Point(16, 36);
         this.label1.Name = "label1";
         this.label1.Size = new System.Drawing.Size(128, 16);
         this.label1.TabIndex = 0;
         this.label1.Text = "Please enter your name:"; 
         this.textBox1.Location = new System.Drawing.Point(152, 32);
         this.textBox1.Name = "textBox1";
         this.textBox1.TabIndex = 1;
         this.textBox1.Text = "";
         this.button1.Location = new System.Drawing.Point(109, 80);
         this.button1.Name = "button1";
         this.button1.TabIndex = 2;
         this.button1.Text = "Enter";
         this.button1.Click += new System.EventHandler(this.button1_Click);
         this.ClientSize = new System.Drawing.Size(292, 126);
         this.Controls.Add(this.button1);
         this.Controls.Add(this.textBox1);
         this.Controls.Add(this.label1);
         this.Name = "form1";
         this.Text = "Visual C#";
         this.ResumeLayout(false);
     }
     private void button1_Click(object sender, System.EventArgs e)
     {
        System.Console.WriteLine("User entered: " + textBox1.Text);
        MessageBox.Show("Welcome, " + textBox1.Text, "Visual C#");
     }
     [STAThread]
     public static void Main()
     {
        Application.EnableVisualStyles();
        Application.Run(new MainForm());
     }
}

MessageBox.Show(String value)

 
using System;
using System.Drawing;
using System.ruponentModel;
using System.Windows.Forms;
public class frmLogin : System.Windows.Forms.Form {
    System.Windows.Forms.TextBox txtUser;
    System.Windows.Forms.Button btnOK;
    System.Windows.Forms.Button btnCancel;
    public frmLogin() {
        txtUser = new System.Windows.Forms.TextBox();
        txtUser.Location = new Point(30, 15);
        txtUser.Size = new Size(250, 20);
        txtUser.Text = "";
        txtUser.Name = "txtUser";
        this.Controls.Add(txtUser);
        btnOK = new System.Windows.Forms.Button();
        btnOK.Location = new Point(40,(txtUser.Location.Y + txtUser.Size.Height + btnOK.Size.Height));
        btnOK.Text = "OK";
        btnOK.Name = "btnOK";
        this.Controls.Add(btnOK);
        btnCancel = new System.Windows.Forms.Button();
        btnCancel.Location = new Point((this.Size.Width -
                                        btnCancel.Size.Width) - 40,
           (txtUser.Location.Y + txtUser.Size.Height + btnOK.Size.Height));
        btnCancel.Text = "Cancel";
        btnCancel.Name = "btnCancel";
        this.Controls.Add(btnCancel);
        this.Size = new Size(this.Size.Width, btnCancel.Location.Y +
                             btnCancel.Size.Height + 60);
        btnCancel.Click += new System.EventHandler(btnCancelHandler);
        btnOK.Click += new System.EventHandler(btnEventHandler);
    }
    private void btnEventHandler(object sender, System.EventArgs e) {
        MessageBox.Show(((Button)sender).Name);
    }
    private void btnCancelHandler(object sender, System.EventArgs e) {
        MessageBox.Show("The second handler");
    }
    [STAThread]
    static void Main() {
        Application.Run(new frmLogin());
    }
}