什么是Android WebView.PictureListener 并当它究竟是叫什么名字？该文档是相当模糊了。

时的图片中的WebView的内容？是不是每一次所谓的的WebView变化的内容（即：每个img元素加载时间）？

的WebView做它的一个图片，这可以看作是一个显示列表里呈现。图片记录一切网页需要借鉴：文字，线条，图像等，这听众可用于通知每当WebView中的内容已被更改的和的它已经准备好要绘制

What is the Android WebView.PictureListener and when is it called exactly? The documentation is quite vague about it.

Is the picture the content of the WebView? Is it called each time the content of the WebView changes (ie: each time a img element is loaded)?

WebView does its rendering inside a Picture, which can be seen as a display list. The picture records everything the web page needs to draw: text, lines, images, etc. This listener can be used to be notified whenever the content of the WebView has changed and it's ready to be drawn.