鼠标事件

The MouseEvent interface represents events that occur due to the user interacting with a pointing device (such as a mouse). Common events using this interface include click, dblclick, mouseup, mousedown.

MouseEvent derives from UIEvent, which in turn derives from Event. Though the MouseEvent.initMouseEvent() method is kept for backward compatibility, creating of a MouseEvent object should be done using the MouseEvent() constructor.

Several more specific events derivate from MouseEvent: WheelEvent and DragEvent.

Constructor

MouseEvent()

Creates a MouseEvent object.

Properties

This interface also inherits properties of its parents, UIEvent and Event.

MouseEvent.altKey 只读

Returns true if the alt key was down when the mouse event was fired.

MouseEvent.button 只读

The button number that was pressed when the mouse event was fired. 

MouseEvent.buttons 只读

The buttons being pressed when the mouse event was fired

MouseEvent.clientX 只读

The X coordinate of the mouse pointer in local (DOM content) coordinates.

MouseEvent.clientY 只读

The Y coordinate of the mouse pointer in local (DOM content) coordinates.

MouseEvent.ctrlKey 只读

Returns true if the control key was down when the mouse event was fired.

MouseEvent.metaKey 只读

Returns true if the meta key was down when the mouse event was fired.

MouseEvent.movementX 只读

The X coordinate of the mouse pointer relative to the position of the last mousemove event.

MouseEvent.movementY 只读

The Y coordinate of the mouse pointer relative to the position of the last mousemove event.

MouseEvent.region 只读

Returns the id of the hit region affected by the event. If no hit region is affected, null is returned.

MouseEvent.relatedTarget 只读

The secondary target for the event, if there is one.

MouseEvent.screenX 只读

The X coordinate of the mouse pointer in global (screen) coordinates.

MouseEvent.screenY 只读

The Y coordinate of the mouse pointer in global (screen) coordinates.

MouseEvent.shiftKey 只读

Returns true if the shift key was down when the mouse event was fired.

MouseEvent.which 只读

The button being pressed when the mouse event was fired.

MouseEvent.mozPressure 只读

The amount of pressure applied to a touch or tablet device when generating the event; this value ranges between 0.0 (minimum pressure) and 1.0 (maximum pressure).

MouseEvent.mozInputSource 只读

The type of device that generated the event (one of the MOZ_SOURCE_* constants listed below). This lets you, for example, determine whether a mouse event was generated by an actual mouse or by a touch event (which might affect the degree of accuracy with which you interpret the coordinates associated with the event). The possible values are:

Constant name	Value	Desription
MouseEvent.MOZ_SOURCE_UNKNOWN	0	The input device is unknown.
MouseEvent.MOZ_SOURCE_MOUSE	1	The event was generated by a mouse (or mouse-like device).
MouseEvent.MOZ_SOURCE_PEN	2	The event was generated by a pen on a tablet.
MouseEvent.MOZ_SOURCE_ERASER	3	The event was generated by an eraser on a tablet.
MouseEvent.MOZ_SOURCE_CURSOR	4	The event was generated by a cursor.
MouseEvent.MOZ_SOURCE_TOUCH	5	The event was generated on a touch interface.
MouseEvent.MOZ_SOURCE_KEYBOARD	6	The event was generated by a keyboard.

Methods

This interface also inherits methods of its parents, UIEvent and Event.

MouseEvent.getModifierState()

Returns the current state of the specified modifier key. See the KeyboardEvent.getModifierState() for details.

MouseEvent.initMouseEvent()

Initializes the value of a MouseEvent created. If the event has already being dispatched, this method does nothing.

Example

This example demonstrates simulating a click (that is programmatically generating a click event) on a checkbox using DOM methods. 

function simulateClick() {
  var evt = new MouseEvent("click", {
    bubbles: true,
    cancelable: true,
    view: window,
  });
  var cb = document.getElementById("checkbox"); //element to click on
  var canceled = !cb.dispatchEvent(evt);
  if(canceled) {
    // A handler called preventDefault
    alert("canceled");
  } else {
    // None of the handlers called preventDefault
    alert("not canceled");
  }
}
document.getElementById("button").addEventListener('click', simulateClick);

<p><label><input type="checkbox" id="checkbox"> Checked</label>
<p><button id="button">Click me</button>

Click on the button to see how the sample works:

Specifications

Browser compatibility

See also

• Its direct parent, UIEvent.