MessageBox.Show Method (String, String, MessageBoxButtons, MessageBoxIcon)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Displays a message box with specified text, caption, buttons, and icon.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public static DialogResult Show(
	string text,
	string caption,
	MessageBoxButtons buttons,
	MessageBoxIcon icon


Type: System.String

The text to display in the message box.

Type: System.String

The text to display in the title bar of the message box.

Type: System.Windows.Forms.MessageBoxButtons

One of the MessageBoxButtons values that specifies which buttons to display in the message box.

Type: System.Windows.Forms.MessageBoxIcon

One of the MessageBoxIcon values that specifies which icon to display in the message box.

Return Value

Type: System.Windows.Forms.DialogResult

One of the DialogResult values.

Exception Condition

The buttons parameter specified is not a member of MessageBoxButtons.


The icon parameter specified is not a member of MessageBoxIcon.


An attempt was made to display the MessageBox in a process that is not running in User Interactive mode. This is specified by the SystemInformation.UserInteractive property.

You can have a maximum of three buttons on the message box.

The following code example demonstrates one of the Show methods when handling the ComboBox.DropDown event. To run the example, paste the following code in a form and call the InitializeComboBox method from the form's constructor or Load method.

// Declare ComboBox1.
internal System.Windows.Forms.ComboBox ComboBox1;

// Initialize ComboBox1.
private void InitializeComboBox()
	this.ComboBox1 = new ComboBox();
	this.ComboBox1.Location = new System.Drawing.Point(128, 48);
	this.ComboBox1.Name = "ComboBox1";
	this.ComboBox1.Size = new System.Drawing.Size(100, 21);
	this.ComboBox1.TabIndex = 0;
	this.ComboBox1.Text	= "Typical";
	string[] installs = new string[]{"Typical", "Compact", "Custom"};

	// Hook up the event handler.
	this.ComboBox1.DropDown +=  
		new System.EventHandler(ComboBox1_DropDown);

// Handles the ComboBox1 DropDown event. If the user expands the  
// drop-down box, a message box will appear, recommending the
// typical installation.
private void ComboBox1_DropDown(object sender, System.EventArgs e)
	MessageBox.Show("Typical installation is strongly recommended.", 
	"Install information", MessageBoxButtons.OK, 


for safe subwindows to call this method. Associated enumeration: UIPermissionWindow.SafeSubWindows

.NET Framework
Available since 1.1
Return to top