Type: System.ComponentModel.CancelEventArgs

System.ComponentModel.CancelEventArgs Class

Assembly: System.dll
Namespace: System.ComponentModel

Summary: Provides data for a cancelable event.

C# Syntax:


        public class CancelEventArgs : EventArgs

Remarks

A cancelable event is raised by a component when it is about to perform an action that can be canceled, such as the Form.Closing event of a Form.

A CancelEventArgs provides the CancelEventArgs.Cancel property to indicate whether the event should be canceled.

Example

The following example uses a CancelEventArgs and a CancelEventHandler to handle the Form.Closing event of a Form. This code assumes that you have created a Form with a class-level Boolean variable named


            myDataIsSaved

// Calls this method from the InitializeComponent() method of your form
    private void OtherInitialize() {
       this.Closing += new CancelEventHandler(this.Form1_Cancel);
       this.myDataIsSaved = new Boolean();
       this.myDataIsSaved = true;
    }
    protected void Form1_Cancel (Object sender, CancelEventArgs e) {
       if (!myDataIsSaved) {
          e.Cancel = true;
          MessageBox.Show("You must save first.");
       }
       else {
          e.Cancel = false;
          MessageBox.Show("Goodbye.");
       }
    }

System.ComponentModel.CancelEventArgs Member List:

Public Constructors

ctor #1	Overloaded: `.ctor()`Default constructor. This constructor is called by derived class constructors to initialize state in this type. Initializes a new instance of the CancelEventArgs class with the CancelEventArgs.Cancel property set to false.
ctor #2	Overloaded: `.ctor(bool cancel)` Initializes a new instance of the CancelEventArgs class with the CancelEventArgs.Cancel property set to the given value.

Public Properties

Cancel

Read-write

Gets or sets a value indicating whether the event should be canceled.

Public Methods

Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

System.Object

System.EventArgs

System.ComponentModel.CancelEventArgs

System.ComponentModel.CancelEventArgs Member Details

Overloaded ctor #1

Summary: Initializes a new instance of the CancelEventArgs class with the CancelEventArgs.Cancel property set to false.

Default constructor. This constructor is called by derived class constructors to initialize state in this type.

C# Syntax:


            public CancelEventArgs();

See also:
CancelEventHandler

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Overloaded ctor #2

Summary: Initializes a new instance of the CancelEventArgs class with the CancelEventArgs.Cancel property set to the given value.

C# Syntax:


            public CancelEventArgs(
   bool cancel
);

Parameters:

cancel

true to cancel the event; otherwise, false.

See also:
CancelEventHandler

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Property: Cancel (read-write)

Summary: Gets or sets a value indicating whether the event should be canceled.

C# Syntax:


            public bool Cancel {get; set;}

Example


                myDataIsSaved

// Calls this method from the InitializeComponent() method of your form
    private void OtherInitialize() {
       this.Closing += new CancelEventHandler(this.Form1_Cancel);
       this.myDataIsSaved = new Boolean();
       this.myDataIsSaved = true;
    }
    protected void Form1_Cancel (Object sender, CancelEventArgs e) {
       if (!myDataIsSaved) {
          e.Cancel = true;
          MessageBox.Show("You must save first.");
       }
       else {
          e.Cancel = false;
          MessageBox.Show("Goodbye.");
       }
    }

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Method: Equals(
object obj
)

Inherited
See base class member description: System.Object.Equals

C# Syntax:


            public virtual bool Equals(
   object obj
);