MouseEvent

MouseEvent 介面表示了由使用者經指標裝置（如滑鼠）進行互動所發生的事件。常見的 MouseEvent 實作事件包括了 click、dblclick (en-US)、mouseup (en-US) 與 mousedown (en-US)。

MouseEvent 繼承自 UIEvent，而 UIEvent 則繼承自 Event。雖然 MouseEvent.initMouseEvent() (en-US) 方法仍然向下相容新的瀏覽器，但現今應該使用 MouseEvent() (en-US) 建構式來建立 MouseEvent 物件。

另外還有一些特定的事件繼承自 MouseEvent：WheelEvent 及 DragEvent。

MouseEvent() (en-US)

建立一個 MouseEvent 物件。

此介面也繼承了其父介面 UIEvent 與 Event 的屬性

MouseEvent.altKey (en-US) Read only

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

MouseEvent.button (en-US) Read only

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

MouseEvent.buttons (en-US) Read only

The buttons being pressed when the mouse event was fired

MouseEvent.clientX (en-US) Read only

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

MouseEvent.clientY (en-US) Read only

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

MouseEvent.ctrlKey (en-US) Read only

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

MouseEvent.metaKey (en-US) Read only

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

MouseEvent.movementX (en-US) Read only

The X coordinate of the mouse pointer relative to the position of the last mousemove (en-US) event.

MouseEvent.movementY (en-US) Read only

The Y coordinate of the mouse pointer relative to the position of the last mousemove (en-US) event.

MouseEvent.offsetX (en-US) Read only

The X coordinate of the mouse pointer relative to the position of the padding edge of the target node.

MouseEvent.offsetY (en-US) Read only

The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.

MouseEvent.pageX (en-US) Read only

The X coordinate of the mouse pointer relative to the whole document.

MouseEvent.pageY (en-US) Read only

The Y coordinate of the mouse pointer relative to the whole document.

MouseEvent.region (en-US) Read only

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

MouseEvent.relatedTarget (en-US) Read only

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

MouseEvent.screenX (en-US) Read only

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

MouseEvent.screenY (en-US) Read only

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

MouseEvent.shiftKey (en-US) Read only

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

MouseEvent.which (en-US) Read only

The button being pressed when the mouse event was fired.

MouseEvent.mozPressure Read only

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 (en-US) Read only

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).

MouseEvent.webkitForce (en-US) Read only

The amount of pressure applied when clicking

MouseEvent.x (en-US) Read only

Alias for MouseEvent.clientX (en-US).

MouseEvent.y (en-US) Read only

Alias for MouseEvent.clientY (en-US)

MouseEvent.WEBKIT_FORCE_AT_MOUSE_DOWN (en-US) Read only

Minimum force necessary for a normal click

MouseEvent.WEBKIT_FORCE_AT_FORCE_MOUSE_DOWN (en-US) Read only

Minimum force necessary for a force click

此介面也繼承了其父介面 UIEvent 與 Event 的方法

MouseEvent.getModifierState() (en-US)

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

MouseEvent.initMouseEvent() (en-US)

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

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:

[1] Requires enabling the ExperimentalCanvasFeatures flag.

• Its direct parent, UIEvent.