DOM basic tutorial event types_basic knowledge

For user event types, the most commonly used are mouse, keyboard, and browser.

1. Mouse events:

Mouse events are frequently used. The following example tests various mouse events

Copy code The code is as follows:

Copy code

The code is as follows:               function TestClick(oEvent) {

              var oDiv = document.getElementById("display");

If (window.event)
oEvent = window.event;
                    oDiv.innerHTML = oEvent.button; //Output button value
            }
               document.onmousedown = TestClick;
              window.onload = TestClick; //Testing that no key is pressed
                                                                                                                                                                                                                      

                                                                                       

2. Keyboard events

There are not many types of keyboard events, only three types of events.

keydown (press a key and hold it down to trigger continuously)

keypress (triggered when a key is pressed and a character is generated, that is, function keys such as Shift, Alt, ctrl, etc. are ignored)

keyup (triggered when a key is released)

Keyboard monitoring example:

Copy code The code is as follows:

Is equivalent to keycode in keypress event, so the following method is used.

Copy code

The code is as follows:oEvent.charCode = (oEvent.type == "keypress")? oEvent.keycode:();

The reason why keyCode is not used is because it represents keyboard keys, not output characters. Therefore, when outputting "a" and "A", keycode is equivalent, and charcode is distinguished by characters.

In addition, in keypress, the keycode value of standard DOM is always 0;

Example: Keyboard event related properties:

Copy code

The code is as follows:

For browsers, various HTML events have their own events, some of which are often encountered by users, such as load, error, select, etc. Commonly used HTML events are as follows:

The load event is one of the commonly used events, because before the page is loaded, the DOM framework has not been built, so no related operations can occur.

Assign load to the window object, and the unload event is equivalent to the onload and onunload methods of the

tag.