MouseEventArgs Class
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MouseEventArgs Class


Provides data for the MouseUp, MouseDown, and MouseMove events.

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

public class MouseEventArgs : EventArgs

System_CAPS_pubmethodMouseEventArgs(MouseButtons, Int32, Int32, Int32, Int32)

Initializes a new instance of the MouseEventArgs class.


Gets which mouse button was pressed.


Gets the number of times the mouse button was pressed and released.


Gets a signed count of the number of detents the mouse wheel has rotated, multiplied by the WHEEL_DELTA constant. A detent is one notch of the mouse wheel.


Gets the location of the mouse during the generating mouse event.


Gets the x-coordinate of the mouse during the generating mouse event.


Gets the y-coordinate of the mouse during the generating mouse event.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

The MouseDown event occurs when the user presses the mouse button while the pointer is over a control. The MouseUp event occurs when the user releases the mouse button while the pointer remains over the control. The MouseMove event occurs when the user moves the mouse pointer over a control. A MouseEventArgs specifies which mouse button is pressed, how many times the mouse button was pressed and released, the coordinates of the mouse, and the amount the mouse wheel moved.

It is possible to receive a MouseDown event without a corresponding MouseUp, if the user switches focus to another application before releasing the mouse button.

These three events exist for the Control, AxHost, and NotifyIcon classes.

For information about the event model, see Handling and Raising Events.

The following code examples handles the MouseDown event on a TextBox control so that clicking the right mouse button selects all the text in the control. This example requires that you have a form that contains a TextBox control that is named textBox1.

private void Form1_Load(object sender, EventArgs e)
    // This line suppresses the default context menu for the TextBox control. 
    textBox1.ContextMenu = new ContextMenu();
    textBox1.MouseDown += new MouseEventHandler(textBox1_MouseDown);

void textBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    if (e.Button == MouseButtons.Right)
        textBox1.Select(0, textBox1.Text.Length);

The following code example uses the Location property to track clicks of the left mouse button and to draw a series of straight line segments in response to user input. The example does not redraw the lines if you hide the form and then redisplay it; this code has been omitted for simplicity.

Point firstPoint;
Boolean haveFirstPoint;

public void EnableDrawing()
    this.MouseDown += new MouseEventHandler(Form1_MouseDownDrawing);

void Form1_MouseDownDrawing(object sender, System.Windows.Forms.MouseEventArgs e)
    if (haveFirstPoint)
        Graphics g = this.CreateGraphics();
        g.DrawLine(Pens.Black, firstPoint, e.Location);
        haveFirstPoint = false;
        firstPoint = e.Location;
        haveFirstPoint = true;

The following code example uses the X and Y properties to display the current position of the mouse pointer in a ToolTip window.

ToolTip trackTip;

private void TrackCoordinates()
    trackTip = new ToolTip();
    this.MouseMove += new MouseEventHandler(Form1_MouseMove);

void Form1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
    String tipText = String.Format("({0}, {1})", e.X, e.Y);
    trackTip.Show(tipText, this, e.Location);

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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