当我在Facebook上,并且控制台打开时,我看到下面的图像.他们怎么做到这一点
解决方法
就像在Firebug中一样,您可以使用%c来设计控制台日志输出.看看我们如何实现Facebook的例子:
console.log("%cStop!","color: red; font-family: sans-serif; font-size: 4.5em; font-weight: bolder; text-shadow: #000 1px 1px;");
(function(url) { // Create a new `Image` instance var image = new Image(); image.onload = function() { // Inside here we already have the dimensions of the loaded image var style = [ // Hacky way of forcing image's viewport using `font-size` and `line-height` 'font-size: 1px;','line-height: ' + this.height + 'px;',// Hacky way of forcing a middle/center anchor point for the image 'padding: ' + this.height * .5 + 'px ' + this.width * .5 + 'px;',// Set image dimensions 'background-size: ' + this.width + 'px ' + this.height + 'px;',// Set image URL 'background: url('+ url +');' ].join(' '); console.log('%c',style); }; // Actually loads the image image.src = url; })('https://i.cloudup.com/Zqeq2GhGjt-3000x3000.jpeg');