这篇由Jan Wolter撰写的文章是我所见过的最好的文章，如果链接失效，你可以在这里找到存档副本。

它很好地解释了所有浏览器键事件，

The keydown event occurs when the key is pressed, followed immediately by the keypress event. Then the keyup event is generated when the key is released. To understand the difference between keydown and keypress, it is useful to distinguish between characters and keys. A key is a physical button on the computer's keyboard. A character is a symbol typed by pressing a button. On a US keyboard, hitting the 4 key while holding down the Shift key typically produces a "dollar sign" character. This is not necessarily the case on every keyboard in the world. In theory, the keydown and keyup events represent keys being pressed or released, while the keypress event represents a character being typed. In practice, this is not always the way it is implemented. For a while, some browers fired an additional event, called textInput, immediately after keypress. Early versions of the DOM 3 standard intended this as a replacement for the keypress event, but the whole notion was later revoked. Webkit supported this between versions 525 and 533, and I'm told IE supported it, but I never detected that, possibly because Webkit required it to be called textInput while IE called it textinput. There is also an event called input, supported by all browsers, which is fired just after a change is made to to a textarea or input field. Typically keypress will fire, then the typed character will appear in the text area, then input will fire. The input event doesn't actually give any information about what key was typed - you'd have to inspect the textbox to figure it out what changed - so we don't really consider it a key event and don't really document it here. Though it was originally defined only for textareas and input boxes, I believe there is some movement toward generalizing it to fire on other types of objects as well.

“KeyPress”现已弃用。请使用KeyDown键。

KeyPress, KeyUp和KeyDown分别类似于:Click, MouseUp和MouseDown。

先下 第二个按键发生(当输入文本时) Up发生在最后(当文本输入完成时)。

webkit是个例外，它有一个额外的事件:

keydown
keypress
textInput     
keyup

下面是一个片段，你可以自己看看什么时候事件被触发:

窗口。addEventListener(“弹起”,日志); 窗口。addEventListener(“键盘按键”,日志); 窗口。addEventListener(“keydown”、日志); 对数函数(事件){ console.log(事件。类型); ｝

似乎onkeypress和onkeydown做的是一样的(在上面已经提到的快捷键的小差异中)。

你可以试试这个:

<textarea type="text" onkeypress="this.value=this.value + 'onkeypress '"></textarea>
<textarea type="text" onkeydown="this.value=this.value + 'onkeydown '" ></textarea>
<textarea type="text" onkeyup="this.value=this.value + 'onkeyup '" ></textarea>

你会看到onkeypress和onkeydown事件都是在按下键时触发的，而不是在按下键时触发的。

不同之处在于，事件不是一次触发，而是多次触发(只要您按住键)。要意识到这一点，并相应地处理它们。

点击这里查看这个答案中最初使用的存档链接。

从这个链接:

理论上，onKeyDown和onKeyUp事件表示正在按下或释放的键，而onKeyPress事件表示正在键入的字符。该理论在所有浏览器中的实现并不相同。

当键按下时，Onkeydown被触发(就像在快捷键;例如，在Ctrl+A中，按下Ctrl键。

Onkeyup在按键释放时被触发(包括modifier/etc按键)

Onkeypress被触发为onkeydown和onkeyup的组合，或者取决于键盘重复(当onkeyup没有被触发时)。(我还没有测试过这种重复行为。如果要测试，请添加注释!)

textInput(仅webkit)在输入一些文本时被触发(例如，Shift+A将输入大写的“A”，但Ctrl+A将选择文本而不输入任何文本输入。在这种情况下，所有其他事件被触发)

基本上，这些事件在不同的浏览器类型和版本上表现不同，我创建了一个小jsBin测试，您可以检查控制台以了解这些事件在您的目标环境中的行为，希望这对您有所帮助。http://jsbin.com/zipivadu/10/edit