如何在设置比例后调度"缩放"事件(d3,zoom.behavior)

Question

一旦我在缩放行为上手动设置了比例,我该如何触发缩放事件？

var zoom = d3.behavior.zoom()
    .scaleExtent([0.5, 4])
    .on('zoom', onzoom);

// later on
zoom.scale(2);

https://github.com/mbostock/d3/wiki/Zoom-Behavior#wiki-scale

Answer 1

首先,您需要将缩放行为附加到SVG对象.同样,您可以在缩放对象上调用缩放功能.

var zoom = d3.behavior.zoom()
    .scaleExtent([0.5, 4])
    .on('zoom', onzoom);

//svgElement is an actual element such as a rect or text or group
svgElement.call(zoom);

// later on
zoom.scale(2);
zoom.event(svgElement);