Introduction
A message box is a
dialog box that is used to display an alert or a message or also let the user
have some options to choose from. A simple message box has an OK button and looks
like Figure 1.
Figure 1
A message box can have a
title and multiple options such as Yes, No, and Cancel. A message box can also
have some input control to take input from a user.
MessageBox Class
The MessageBox class in
WPF represents a modal message box dialog, which is defined in the
System.Windows namespace. The Show static method of the MessageBox is the only
method that is used to display a message box. The Show method returns a
MessageBoxResult enumeration that has values - None, OK, Cancel, Yes, and No.
We can use MessageBoxResult to find out what button was clicked on a MessageBox
and take an appropriate action.
Show method has 13
overloaded methods. Here are the code samples and their results of these 13
overloaded methods.
Simple MessageBox
A simple MessageBox
shows a message and have only OK button. Clicking on OK button closes the
MessageBox. The following line of code uses Show method to display a message
box with a simple message.
MessageBoxResult
result = MessageBox.Show("Hello MessageBox");
The MessageBox generated
by the above line of code is a modal dialog with an OK button on it and looks
like Figure 2.
Figure 2
MessageBox with Title
A MessageBox can have a
title. The first parameter of the Show method is a message string and second
parameter is title string of the dialog. The following code snippet creates a
MessageBox with a message and a title.
MessageBoxResult
result = MessageBox.Show("Hello MessageBox", "Confirmation");
The output looks like
Figure 3.
Figure 3
MessageBox with Owner
A MessageBox does not
have an owner by default but you can specify an owner by setting the following
code. In this code, the first parameter is the current Window.
MessageBoxResult
result = MessageBox.Show(this, "Hello MessageBox");
MessageBoxButton Enumeration
The MessageBoxButton
enumeration is responsible for showing various buttons on the dialog. It has
following values:
- OK - OK button is displayed
- OKCancel - OK and Cancel buttons are displayed
- YesNo - Yes and No buttons are displayed
- YesNoCancel - Yes, No, and Cancel buttons are
displayed
MessageBox with Title, Yes and No
Buttons
A MessageBox can be used
to ask user a question and have Yes and No buttons. Based on the user selection (Yes or No), you
can execute the appropriate code. The third parameter of the Show method is a
MessageBoxButton enumeration.
The following code
snippet creates a MessageBox with a message, a title, and two Yes and No
buttons.
if (MessageBox.Show("Do
you want to close this window?",
"Confirmation",
MessageBoxButton.YesNo) == MessageBoxResult.Yes)
{
// Close the
window
}
else
{
// Do not close
the window
}
The output looks like
Figure 4.
Figure 4
MessageBox with Title, Yes, No and Cancel
Buttons
The following code
snippet creates a MessageBox with a message, a title, and two Yes, No, and
Cancel buttons.
MessageBoxResult
result = MessageBox.Show("Do you want to close this window?",
"Confirmation",
MessageBoxButton.YesNoCancel);
if
(result == MessageBoxResult.Yes)
{
// Yes code here
}
else if (result == MessageBoxResult.No)
{
// No code here
}
else
{
// Cancel code
here
}
The output looks like
Figure 5.
Figure 5
MessageBox with Title, Icon, Yes and No
Buttons
A MessageBox also allows
you to place an icon that represents the message and comes with some built in
icons. The MessageBoxImage enumeration represents an icon. Here is a list of
MessageBoxImage enumeration values that represent the relative icons.
- None
-
Hand
- Question
- Exclamation
- Asterisk
- Stop
- Error
- Warning
- Information
The following code
snippet creates a MessageBox with a message, a title, and two Yes and No
buttons and an icon.
string
message = "Are you sure?";
string
caption = "Confirmation";
MessageBoxButton
buttons = MessageBoxButton.YesNo;
MessageBoxImage
icon = MessageBoxImage.Question;
if (MessageBox.Show(message, caption, buttons, icon)
== MessageBoxResult.OK)
{
// OK code here
}
else
{
// Cancel code
here
}
The output looks like
Figure 6.
Figure 6
MessageBox with Title, OK, and Cancel
Buttons
By simply using MessageBoxButton.YesNo
in the Show method creates a MessageBox with OK and Cancel buttons. The
following code snippet creates a MessageBox with a message, a title, and two OK
and Cancel buttons.
if (MessageBox.Show("Do
you want to close this window?",
"Confirmation",
MessageBoxButton.YesNo) == MessageBoxResult.Yes)
{
// Close the
window
}
else
{
// Do not close
the window
}
The output looks like
Figure 7.
Figure 7
MessageBox with Title, Icon, OK, and Cancel
Buttons
The following code
snippet creates a MessageBox with a message, a title, icon, and two OK and Cancel
buttons.
MessageBoxResult
result = MessageBox.Show(this, "If you close
this window, all data will be lost.",
"Confirmation",
MessageBoxButton.OKCancel, MessageBoxImage.Warning);
if
(result == MessageBoxResult.OK)
{
// Yes code here
}
else
{
// No code here
}
The output looks like
Figure 8.
Figure 8
Mixing it
These are not only options.
You can mix any of these options to show whatever kind of MessageBox you want to
display.
Customizing MessageBox
Even though it looks like
WPF MessageBox is a part of System.Windows namespace, it is just a wrapper of Win32
API and this is why you can't use it at design-time in XAML or customize it. To
customize a MessageBox, you will be better off creating your own Custom Control. See my articles on How to build Custom Controls in WPF by searching this website for custom control in WPF.
Summary
In this tutorial, we saw various avatars (reincarnations) of MessageBox in WPF.