Csharp/CSharp Tutorial/GUI Windows Forms/MessageBox

Call Show method to display a MessageBox

<source lang="csharp">class MessageBoxHelloWorld {

   public static void Main() {
       System.Windows.Forms.MessageBox.Show("Hello, world!");
   }

}</source>

Display MessageBox in Button event

<source lang="csharp">using System; using System.Windows.Forms; using System.Drawing;

class ButtonEventMessageBox : Form {

 Button StopButton; 

 public ButtonEventMessageBox() { 
   Text = "Adding a Stop Button"; 

   StopButton = new Button(); 
   StopButton.Text = "Stop"; 
   StopButton.Location = new Point(100, 100); 

   StopButton.Click += StopButtonClick; 
   Controls.Add(StopButton); 
 }   

 [STAThread] 
 public static void Main() { 
   ButtonEventMessageBox skel = new ButtonEventMessageBox(); 

   Application.Run(skel); 
 } 

 protected void StopButtonClick(object who, EventArgs e) { 
   DialogResult result = MessageBox.Show("Stop Program?", 
                           "Terminate", 
                           MessageBoxButtons.YesNo); 

   if(result == DialogResult.Yes) 
       Application.Exit(); 
 } 

}</source>

Get result from a MessageBox

<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; public class MainClass {

   public static void Main(){
       DialogResult result = MessageBox.Show("Close?", "Really quit?",
           MessageBoxButtons.YesNo, MessageBoxIcon.Question);
       if (result == DialogResult.No)
           Console.WriteLine("NO");
       else{
           Console.WriteLine("Yes");
       }    
   }

}</source>

Yes

Show method with button and icon settings

<source lang="csharp">using System; using System.Windows.Forms; public class MainClass {

   public static void Main() {
       DialogResult dr = MessageBox.Show("Do you want to create a new file?",
                                         "WonderWord",
                                         MessageBoxButtons.YesNoCancel,
                                         MessageBoxIcon.Question);
       if (dr == DialogResult.Yes) {
           // "Yes" processing
       } else if (dr == DialogResult.No) {
           // "No" processing
       } else {
           // "Cancel" processing
       }
   }

}</source>

Show method with message and window title

<source lang="csharp">using System; using System.Windows.Forms; class MainForm : Form {

   [STAThread]
   public static void Main() {
       MessageBox.Show("Welcome," , "Visual C#");
   }

}</source>

Simplest MessageBox

<source lang="csharp">using System; using System.Windows.Forms; class MainClass {

    public static void Main()
    {
       MessageBox.Show("Hello...");
    }

}</source>