`MessageBox.Show`

This VB.NET function displays a dialog box. It interrupts the user, and immediately blocks further interaction. Only one function call is needed.

This tutorial begins with many different calls to MessageBox.Show. You can find the one that matches what you need, and use the syntax.

Some examples

This event handler will show the message boxes. The MessageBox.Show function is a Public Shared Function type. It can be called without an instance reference.

Tip You can directly invoke MessageBox.Show. The method receives different numbers of parameters.

Here We placed the MessageBox.Show calls into the Form1 constructor. In your programs, place MessageBox.Show where a dialog is needed.

Public Class Form1
    Public Sub New()
        ' Use 1 argument.
        MessageBox.Show("Dot Net Perls is awesome.")

        ' Use 2 arguments.
        MessageBox.Show("Dot Net Perls is awesome.",
                        "Important Message")

        ' Use 3 arguments.
        Dim result1 As DialogResult = MessageBox.Show("Is Dot Net Perls awesome?",
                                                      "Important Question",
                                                      MessageBoxButtons.YesNo)

        ' Use 4 arguments.
        Dim result2 As DialogResult = MessageBox.Show("Is Dot Net Perls awesome?",
                                                      "Important Query",
                                                      MessageBoxButtons.YesNoCancel,
                                                      MessageBoxIcon.Question)

        ' Use 5 arguments.
        Dim result3 As DialogResult = MessageBox.Show("Is this website awesome?",
            "The Question",
            MessageBoxButtons.YesNoCancel,
            MessageBoxIcon.Question,
            MessageBoxDefaultButton.Button2)

        ' Test DialogResult.
        If result1 = DialogResult.Yes And
            result2 = DialogResult.Yes And
            result3 = DialogResult.No Then
            MessageBox.Show("You answered yes, yes and no.")
        End If

        ' Use 7 arguments.
        MessageBox.Show("Dot Net Perls is the best.",
            "Critical Warning",
            MessageBoxButtons.OKCancel,
            MessageBoxIcon.Warning,
            MessageBoxDefaultButton.Button1,
            MessageBoxOptions.RightAlign,
            True)
    End Sub
End Class

Visual Studio

The IntelliSense feature is useful for scrolling through all the possible function calls. The enumerated constants dictate the appearance and behavior of the message boxes.

Note The overloads with one and two parameters are simplistic and have only one button (OK).

Note 2 The longer overloads have multiple buttons, captions, default buttons, and icons, and this only samples the features.

Public Class Form1
    Public Sub New()
        ' Use 1 argument.
        MessageBox.Show() ' ...
    End Sub
End Class

Notes, continued

Add the statements in the example to show dialog boxes when the program is executed. The methods might cause horizontal scrolling in the Visual Studio editor window.

Tip To fix this, you can use the underscore preceded by a space character at the end of each line.

And This allows you to use a multiple-line function call syntax. Newer versions of VB.NET are more relaxed in newline handling.

`DialogResult`

Let us consider the Dialog Results in the program. You can use a Dim variable As DialogResult and then assign this to the result of MessageBox.Show.

We explored the MessageBox.Show function. We called into the MessageBox.Show overloads, and noted the usage of the DialogResult type.