C# MessageBox in Windows Forms displays a message with the given text and action buttons. You can also use MessageBox control to add additional options such as a caption, an icon, or help buttons. In this article, you'll learn how to display and use a MessageBox in C# WinForms app. You will also learn how to use C# MessageBox class dynamically in code samples. 
C# MessageBox
MessageBox class has an overloaded static Show method that displays a message box with a message and action buttons. The action buttons can be OK and Cancel, Yes and No etc. Here are some of the options that can be used in C# message box.
Simple MessageBox
The simplest form of a MessageBox is a dialog with text and OK button. When you click OK button, the box disappears.
The following code snippet creates a simple Message Box.
string message = "Simple MessageBox";  
MessageBox.Show(message);
MessageBox with Title
The following code snippet creates a simple MessageBox with a title. 
string message = "Simple MessageBox";  
string title = "Title";  
MessageBox.Show(message, title); 
 ![MessageBox with Title]()
MessageBox with Buttons
A MessageBox can have different button combinations such as YesNo and OKCancel. The MessageBoxButtons enumeration represents the buttons to be displayed on a MessageBox and has following values.
	- OK
- OKCancel
- AbortRetryIgnore
- YesNoCancel
- YesNo
- RetryCancel
The following code snippet creates a MessageBox with a title and Yes and No buttons. This is a typical MessageBox you may call when you want to close an application. If the Yes button is clicked, the application will be closed. The Show method returns a DialogResult enumeration.
string message = "Do you want to close this window?";  
string title = "Close Window";  
MessageBoxButtons buttons = MessageBoxButtons.YesNo;  
DialogResult result = MessageBox.Show(message, title, buttons);  
if (result == DialogResult.Yes) {  
    this.Close();  
} else {  
    // Do something  
}
![MessageBox with Buttons]()
MessageBox with Icon
A MessageBox can display an icon on the dialog. A MessageBoxIcons enumeration represents an icon to be displayed on a MessageBox and has the following values.
	- None
- Hand
- Question
- Exclamation
- Asterisk
- Stop
- Error
- Warning
- Information
The following code snippet creates a MessageBox with a title, buttons, and an icon.
string message = "Do you want to abort this operation?";  
string title = "Close Window";  
MessageBoxButtons buttons = MessageBoxButtons.AbortRetryIgnore;  
DialogResult result = MessageBox.Show(message, title, buttons, MessageBoxIcon.Warning);  
if (result == DialogResult.Abort) {  
    this.Close();  
}  
elseif(result == DialogResult.Retry) {  
    // Do nothing  
}  
else {  
    // Do something  
}
![MessageBox with Icon]()
MessageBox with Default Button
We can also set the default button on a MessageBox. By default, the first button is the default button. The MessageBoxDefaultButton enumeration is used for this purpose and it has the following three values.
The following code snippet creates a MessageBox with a title, buttons, and an icon and sets the second button as a default button.
string message = "Do you want to abort this operation?";  
string title = "Close Window";  
MessageBoxButtons buttons = MessageBoxButtons.AbortRetryIgnore;  
DialogResult result = MessageBox.Show(message, title, buttons, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2);  
if (result == DialogResult.Abort) {  
    this.Close();  
}  
elseif(result == DialogResult.Retry) {  
    // Do nothing  
}  
else {  
    // Do something  
}
![MessageBox with Default Button]()
MessageBox with Message Options
MessageBoxOptions enumeration represents various options and has the following values.
	- ServiceNotification
- DefaultDesktopOnly
- RightAlign
- RtlReading
The following code snippet creates a MessageBox with various options.
DialogResult result = MessageBox.Show(message, title, buttons,  
MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2,  
MessageBoxOptions.RightAlign|MessageBoxOptions.RtlReading);  
![MessageBox with Message Options]() 
 
MessageBox with Help Button
A MessageBox can have an extra button called Help button. This is useful when we need to display a help file. The following code snippet creates a MessageBox with a Help button.
DialogResult result = MessageBox.Show(message, title, buttons,  
MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2,  
MessageBoxOptions.RightAlign, true );  
![MessageBox with Help Button]()
We can also specify a help file when the Help button is clicked. The following code snippet references a help file.
DialogResult result = MessageBox.Show(message, title,  
buttons, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1, 0, "helpfile.chm");  
Summary
In this article, we discussed how to create and use a MessageBox in a Windows Forms application.