TONT 33503 为什么行内自动完成功能默认是关闭的？

原文链接：https://devblogs.microsoft.com/oldnewthing/20051102-48/?p=33503

Earlier versions of Internet Explorer used inline autocomplete, but newer versions use drop-down autocomplete that requires you to press the down-arrow key to select an item from the drop-down. Why the change?

早期版本的 Internet Explorer 启用了行内自动完成，但新版本改成了下拉列表式的自动完成，需要用户按下箭头键来在列表中选择一项。为什么会有这种变动呢？

Because it interferes with normal keyboard operation.

因为先前的设计影响了正常的键盘操作。

Suppose http://www.microsoft.com/windows/ is in your history, but you want to go to http://www.microsoft.com/. As you type the desired destination, inline autocomplete kicks in and fills in the remainder of the URL for you, http://www.microsoft.com/windows/. If you aren’t watching the screen and just hit Enter, you end up going to the autocompleted URL instead of the URL you typed. Oops.

假设 http://www.microsoft.com/windows/ 在你的浏览记录中，但你想浏览的是 http://www.microsoft.com/。当你在地址栏中输入要访问的网址时，行内自动完成发挥了作用，帮你补全了余下的部分，（使网址变成了）http://www.microsoft.com/windows/。如果你（低头敲键盘）没看屏幕就直接按下了回车键，结果就是访问了自动完成给出的 URL 而不是你录入的网址。哎呀。

To me, this is a fatal flaw, namely that one has to be watching the screen to perform an operation that one would think consisted purely of typing. In particular, this creates problems for people with limited visual capability who necessarily “type blind” most of the time.

对我来说，这是个难以接受的缺陷，使得一项让只管录入就能完成的工作，变成了需要盯着屏幕才能完成的情况。尤其是针对事实上总是在『盲打』的视弱用户而言，便是一个大问题。

Even using Tab as the autocomplete character suffers from the same flaw. Consider the Run dialog or IE’s address bar. In those places, the Tab key moves you around the window. (To the OK, Cancel, and Browse buttons on the Run dialog, or into the web page itself for IE.) If the Tab key were the autocomplete completion key, it wouldn’t be possible to Tab around the dialog/window any more. For example, suppose you want to browse around your C drive, so you type C:\ into the Run dialog and hit Tab three times to get to the Browse button. But, oops, the Tab key autocompletes, so instead of browsing C:\, you’re browsing whatever directory in your C: drive the autocomplete engine decided to show you.

就算将自动完成功能改成用 Tab 键，也会产生同样的问题。考虑在『运行』对话框或 IE 的地址栏里，在这些地方，Tab 键会将你的焦点移动到其它控件上。（例如在『运行』对话框中移动到『确定』、『取消』或『浏览』按钮上，或者在 IE 中移动到网页上去。）如果让 Tab 键作为自动完成的案件，那么就无法再用其在对话框或窗口中的控件之间进行切换了。举个例子，假设你想浏览C盘的内容，于是你就在『运行』对话框中输入了 C:\，然后按了 3 下 Tab 键想移动到『浏览』按钮上，然而这时 Tab 键是自动完成键了，于是你输入的路径就变成了自动完成引擎帮你决定的、你的 C 盘中随便哪个目录的内容，而不是浏览 C:\ 的内容了。