td里面的内容是用ng-repeat写的，按钮如何添加提示信息？

Answer 1

可以用bootstrap的工具提示来实现
Tooltips tooltip.js

Inspired by the excellent jQuery.tipsy plugin written by Jason Frame; Tooltips are an updated version, which don't rely on images, use CSS3 for animations, and data-attributes for local title storage.

Tooltips with zero-length titles are never displayed.

Examples
Hover over the links below to see tooltips:

Tight pants next level keffiyeh you probably haven't heard of them. Photo booth beard raw denim letterpress vegan messenger bag stumptown. Farm-to-table seitan, mcsweeney's fixie sustainable quinoa 8-bit american apparel have a terry richardson vinyl chambray. Beard stumptown, cardigans banh mi lomo thundercats. Tofu biodiesel williamsburg marfa, four loko mcsweeney's cleanse vegan chambray. A really ironic artisan whatever keytar, scenester farm-to-table banksy Austin twitter handle freegan cred raw denim single-origin coffee viral.

<button type="button" class="btn btn-default" data-toggle="tooltip" data-placement="left" title="Tooltip on left">Tooltip on left</button>

<button type="button" class="btn btn-default" data-toggle="tooltip" data-placement="top" title="Tooltip on top">Tooltip on top</button>

<button type="button" class="btn btn-default" data-toggle="tooltip" data-placement="bottom" title="Tooltip on bottom">Tooltip on bottom</button>

<button type="button" class="btn btn-default" data-toggle="tooltip" data-placement="right" title="Tooltip on right">Tooltip on right</button>

完了之后，将你的提示信息写进ng-repeat的数据对象中，将title中写死的内容，替换成title="{{obj.title}}"就可以了