private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
    // Displays a message box prompting the user to confirm whether they wish to exit the application.
    if(XtraMessageBox.Show("Do you want to quit the application?", "Confirmation", MessageBoxButtons.YesNo) == DialogResult.No) {
        e.Cancel = true;
    }
}

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs)
    ' Displays a message box prompting the user to confirm whether they wish to exit the application.
    If XtraMessageBox.Show("Do you want to quit the application?", "Confirmation", MessageBoxButtons.YesNo) = DialogResult.No Then
        e.Cancel = True
    End If
End Sub

private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
    // Creates and initializes an object with message box settings.
    XtraMessageBoxArgs args = new XtraMessageBoxArgs() {
        // Sets the caption of the message box.
        Caption = "Confirmation",
        // Sets the message of the message box.
        Text = "Do you want to close the application?",
        // Sets the buttons of the message box.
        Buttons = new DialogResult[] { DialogResult.Yes, DialogResult.No },
        // Sets the auto-close options of the message box.
        AutoCloseOptions = new AutoCloseOptions() {
            // Sets the delay before the message box automatically closes.
            Delay = 5000,
            // Displays the timer on the default button.
            ShowTimerOnDefaultButton = true
        }
    };
    // Displays the message box and checks if a user clicked "No".
    if(XtraMessageBox.Show(args) == DialogResult.No)
        e.Cancel = true;
}

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs)
    ' Creates and initializes an object with message box settings.
    Dim args As XtraMessageBoxArgs = New XtraMessageBoxArgs() With {
        ' Sets the caption of the message box.
        .Caption = "Confirmation",
        ' Sets the message of the message box.
        .Text = "Do you want to close the application?",
        ' Sets the buttons of the message box.
        .Buttons = New DialogResult() {DialogResult.Yes, DialogResult.No},
        ' Sets the auto-close options of the message box.
        .AutoCloseOptions = New AutoCloseOptions() With {
            ' Sets the delay before the message box automatically closes.
            .Delay = 5000,
            ' Displays the timer on the default button.
            .ShowTimerOnDefaultButton = True
        }
    }
    ' Displays the message box and checks if a user clicked "No".
    If XtraMessageBox.Show(args) Is DialogResult.No Then e.Cancel = True
End Sub

private void Form1_Load(object sender, EventArgs e) {
    // Creates a new XtraMessageBoxArgs instance.
    XtraMessageBoxArgs args = new XtraMessageBoxArgs() {
        // Sets the caption of the message box.
        Caption = "This is a trial version",
        // Sets the message text to display in the message box.
        Text = "You are using a trial version. The trial period expires in 30 days.",
        // Sets buttons to display in the message box.
        Buttons = new DialogResult[] { DialogResult.OK },
        // Enables the "Do not show this message again" check box in the message box.
        DoNotShowAgainCheckBoxVisible = true,
        // Aligns the button(s) to the far right of the message box.
        ButtonAlignment = DevExpress.Utils.HorzAlignment.Far,
    };
    // Attaches event handlers for when the message box is loaded and closed.
    args.Load += Args_Load;
    args.Closed += Args_Closed;
    XtraMessageBox.Show(args);
}

// This method is called when the message box is closed.
private void Args_Closed(object sender, XtraMessageBoxClosedArgs e) {
    // Saves the message box settings to the registry.
    e.SaveToRegistry();
}

// This method is called when the message box is loaded.
private void Args_Load(object sender, XtraMessageBoxLoadArgs e) {
    // Restores the message box settings from the registry.
    e.RestoreFromRegistry();
}

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    ' Creates a new XtraMessageBoxArgs instance.
    Dim args As New XtraMessageBoxArgs() With {
        ' Sets the caption of the message box.
        .Caption = "This is a trial version",
        ' Sets the message text to display in the message box.
        .Text = "You are using a trial version. The trial period expires in 30 days.",
        ' Sets the button(s) to display in the message box.
        .Buttons = {DialogResult.OK},
        ' Enables the "Do not show this message again" check box in the message box.
        .DoNotShowAgainCheckBoxVisible = True,
        ' Aligns the button(s) to the far right of the message box.
        .ButtonAlignment = DevExpress.Utils.HorzAlignment.Far
    }
    ' Attaches event handlers for when the message box is loaded and closed.
    AddHandler args.Load, AddressOf Args_Load
    AddHandler args.Closed, AddressOf Args_Closed
    XtraMessageBox.Show(args)
End Sub

' This method is called when the message box is closed.
Private Sub Args_Closed(sender As Object, e As XtraMessageBoxClosedArgs)
    ' Saves the message box settings to the registry.
    e.SaveToRegistry()
End Sub

' This method is called when the message box is loaded.
Private Sub Args_Load(sender As Object, e As XtraMessageBoxLoadArgs)
    ' Restores the message box settings from the registry.
    e.RestoreFromRegistry()
End Sub

private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
  // Create and initialize an object with message box settings.
  XtraMessageBoxArgs args = new XtraMessageBoxArgs() {
    Caption = "Warning",
    Text = "Do you want to quit?",
    Buttons = new DialogResult[] { DialogResult.Yes, DialogResult.No }
    };
  // Assign a message box icon.
  args.ImageOptions.SvgImage = svgImageCollection1[0];
  args.ImageOptions.SvgImageSize = new Size(24, 24);
  // Display the message box and close the application if the user clicks "Yes".
  if (XtraMessageBox.Show(args) == DialogResult.No)
    e.Cancel = true;
}

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
  ' Create and initialize an object with message box settings.
  Dim args As New XtraMessageBoxArgs() With {
    .Caption = "Warning",
    .Text = "Do you want to quit?",
    .Buttons = New DialogResult() { DialogResult.Yes, DialogResult.No }
  }
  ' Assign a message box icon.
  args.ImageOptions.SvgImage = svgImageCollection1(0)
  args.ImageOptions.SvgImageSize = New Size(24, 24)
  ' Display the message box and close the application if the user clicks "Yes".
  If XtraMessageBox.Show(args) = DialogResult.No Then
    e.Cancel = True
  End If
End Sub

// Initializes an XtraMessageBoxArgs object to hold message box arguments.
XtraMessageBoxArgs args = new XtraMessageBoxArgs();
// Sets the message box caption.
args.Caption = "Message";
// Sets the message box text.
args.Text = "Buttons in this message box show custom images.";
// Sets message box buttons.
args.Buttons = new DialogResult[] { DialogResult.OK, DialogResult.Cancel, DialogResult.Retry};
// Attaches an event handler to the message box Showing event.
args.Showing += Args_Showing;
// Shows the message box with the specified arguments.
XtraMessageBox.Show(args);

// The event handler for the message box Showing event.
private void Args_Showing(object sender, XtraMessageShowingArgs e) {
    // Loops through all controls in the message box.
    foreach (var control in e.MessageBoxForm.Controls) {
        // Checks if a control is a SimpleButton.
        SimpleButton button = control as SimpleButton;
        if (button != null) {
            // Sets the size of the button image to 16x16.
            button.ImageOptions.SvgImageSize = new Size(16, 16);
            // Sets a custom image for each button.
            switch (button.DialogResult.ToString()) {
                case ("OK"): 
                    button.ImageOptions.SvgImage = svgImageCollection1[0];
                    break;
                case ("Cancel"):
                    button.ImageOptions.SvgImage = svgImageCollection1[1];
                    break;
                case ("Retry"):
                    button.ImageOptions.SvgImage = svgImageCollection1[2];
                    break;
            }
        }
    }
}

' Initializes an XtraMessageBoxArgs object to hold message box arguments.
Dim args As XtraMessageBoxArgs = New XtraMessageBoxArgs
' Sets the message box caption.
args.Caption = "Message"
' Sets the message box text.
args.Text = "Buttons in this message box show custom images."
' Sets message box buttons.
args.Buttons = New DialogResult() {DialogResult.OK, DialogResult.Cancel, DialogResult.Retry}
' Attaches an event handler to the message box Showing event.
args.Showing = (args.Showing + Args_Showing)
' Shows the message box with the specified arguments.
XtraMessageBox.Show(args)

' The event handler for the message box Showing event.
Private Sub Args_Showing(ByVal sender As Object, ByVal e As XtraMessageShowingArgs)
    ' Loops through all controls in the message box.
    For Each control In e.MessageBoxForm.Controls
        ' Checks if a control is a SimpleButton.
        Dim button As SimpleButton = CType(control,SimpleButton)
        If (Not (button) Is Nothing) Then
            ' Sets the size of the button image to 16x16.
            button.ImageOptions.SvgImageSize = New Size(16, 16)
            ' Sets a custom image for each button.
            Select Case (button.DialogResult.ToString)
                Case "OK"
                    button.ImageOptions.SvgImage = svgImageCollection1(0)
                Case "Cancel"
                    button.ImageOptions.SvgImage = svgImageCollection1(1)
                Case "Retry"
                    button.ImageOptions.SvgImage = svgImageCollection1(2)
            End Select                
        End If            
    Next
End Sub

// Creates a new instance of XtraMessageBoxArgs.
XtraMessageBoxArgs args = new XtraMessageBoxArgs();
// Sets the caption for the message box.
args.Caption = "Message";
// Sets the text for the message box.
args.Text = "This message has custom font settings.";
// Sets the buttons for the message box.
args.Buttons = new DialogResult[] { DialogResult.OK};
// Subscribes to the Showing event of the message box.
args.Showing += Args_Showing;

// Shows the message box and converts the result to a string.
XtraMessageBox.Show(args).ToString();

// The event handler for the Showing event of the message box.
private void Args_Showing(object sender, XtraMessageShowingArgs e) {
    // Makes the message box caption bold.
    e.Form.Appearance.FontStyleDelta = FontStyle.Bold;    
    // Increases the font size and height of the OK button.
    MessageButtonCollection buttons = e.Buttons as MessageButtonCollection;
    SimpleButton btn = buttons[System.Windows.Forms.DialogResult.OK] as SimpleButton;
    if (btn != null) {
        btn.Appearance.FontSizeDelta = 15;
        btn.Height += 10;
    }
}

' Creates a new instance of XtraMessageBoxArgs.
Dim args As New XtraMessageBoxArgs()
' Sets the caption for the message box.
args.Caption = "Message"
' Sets the text for the message box.
args.Text = "This message has custom font settings."
' Sets the buttons for the message box.
args.Buttons = New DialogResult() {DialogResult.OK}
' Subscribes to the Showing event of the message box.
AddHandler args.Showing, AddressOf Args_Showing

' Shows the message box and converts the result to a string.
XtraMessageBox.Show(args).ToString()

' The event handler for the message box Showing event.
Private Sub Args_Showing(ByVal sender As Object, ByVal e As XtraMessageShowingArgs)
    ' Makes the message box caption bold.
    e.Form.Appearance.FontStyleDelta = FontStyle.Bold    
    ' Increases the font size and height of the OK button.
    Dim buttons As MessageButtonCollection = TryCast(e.Buttons, MessageButtonCollection)
    Dim btn As SimpleButton = TryCast(buttons(System.Windows.Forms.DialogResult.OK), SimpleButton)
    If btn IsNot Nothing Then
        btn.Appearance.FontSizeDelta = 15
        btn.Height += 10
    End If
End Sub

private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
    // Creates a new instance of the XtraMessageBoxArgs class.
    XtraMessageBoxArgs args = new XtraMessageBoxArgs();

    // Sets AllowHtmlText to true to allow HTML formatting in the message box text.
    args.AllowHtmlText = DefaultBoolean.True;

    // Sets the size of the image displayed in the message box.
    svgImageCollection1.ImageSize = new Size(24, 24);

    // Sets the SVG images to be displayed in the message box.
    args.HtmlImages = svgImageCollection1;

    // Sets the caption of the message box.
    args.Caption = "Error";

    // Sets the message to be displayed in the message box.
    args.Text = "<p align = center><image=actions_deletecircled>

" +
                "<b>Error</b>
" +
                "Oops, something went wrong.
" +
                "Please try again later.</p>";

    // Sets the buttons to be displayed in the message box.
    args.Buttons = new DialogResult[] { DialogResult.Retry, DialogResult.Cancel };

    // Displays the message box with the specified arguments.
    XtraMessageBox.Show(args);
}

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs)
    ' Creates a new instance of the XtraMessageBoxArgs class.
    Dim args As New XtraMessageBoxArgs()

    ' Sets AllowHtmlText to true to allow HTML formatting in the message box text.
    args.AllowHtmlText = DefaultBoolean.True

    ' Sets the size of the image displayed in the message box.
    svgImageCollection1.ImageSize = New Size(24, 24)

    ' Sets the SVG images to be displayed in the message box.
    args.HtmlImages = svgImageCollection1

    ' Sets the caption of the message box.
    args.Caption = "Error"

    ' Sets the message to be displayed in the message box.
    args.Text = "<p align = center><image=actions_deletecircled>

" & _
                "<b>Error</b>
" & _
                "Oops, something went wrong.
" & _
                "Please try again later.</p>"

    ' Sets the buttons to be displayed in the message box.
    args.Buttons = New DialogResult() {DialogResult.Retry, DialogResult.Cancel}

    ' Displays the message box with the specified arguments.
    XtraMessageBox.Show(args)
End Sub

XtraMessageBox.ButtonsAlignment = HorizontalAlignment.Right;

XtraMessageBox.ButtonsAlignment = HorizontalAlignment.Right

void messageButton_Click(object sender, EventArgs e) {
    XtraMessageBoxArgs args = new XtraMessageBoxArgs() {
        Caption = "Tip",
        Text = "Hello DevExpress!",
        Buttons = new DialogResult[] { DialogResult.OK },
    };
    args.ImageOptions.SvgImage = svgImageCollection1["info"];
    args.ImageOptions.SvgImageSize = new Size(32, 32);
    args.Showing += Args_Showing;
    XtraMessageBox.Show(args);
}
void Args_Showing(object sender, XtraMessageShowingArgs e) {
    // Get the screen working area.
    Rectangle workingArea = Screen.PrimaryScreen.WorkingArea;

    // Calculate bottom-right position.
    int x = workingArea.Right - e.MessageBoxForm.Width;
    int y = workingArea.Bottom - e.MessageBoxForm.Height;

    // Define message box start position.
    e.MessageBoxForm.StartPosition = FormStartPosition.Manual;
    e.MessageBoxForm.Location = new Point(x, y);

    // Display the message box in the Windows taskbar.
    e.MessageBoxForm.ShowInTaskbar = true;
}