html2canvas截取整个页面

首先引入jQuery，

其次引入html2canvas.js，

savePic为触发点击事件的按钮，

contaner为整个DIV容器

有需要做则部分的小伙伴可以参考参考

$(".savePic").on("click", function() {
		var getPixelRatio = function(context) { // 获取设备的PixelRatio
			var backingStore = context.backingStorePixelRatio ||
				context.webkitBackingStorePixelRatio ||
				context.mozBackingStorePixelRatio ||
				context.msBackingStorePixelRatio ||
				context.oBackingStorePixelRatio ||
				context.backingStorePixelRatio || 1;
			return (window.devicePixelRatio || 1) / backingStore;
		};
		var shareContent = $("#contaner")[0];
		var width = shareContent.offsetWidth;
		var height = shareContent.offsetHeight;
		var canvas = document.createElement("canvas");
		var context = canvas.getContext('2d');
		var scale = getPixelRatio(context); 
		canvas.width = width * scale;
		canvas.height = height * scale;
		canvas.style.width = width + 'px';
		canvas.style.height = height + 'px';
		context.scale(scale, scale);

		var opts = {
			scale: scale,
			canvas: canvas,
			 width,
			height: height,
			dpi: window.devicePixelRatio
		};
		
		html2canvas(shareContent, opts).then(function(canvas) {
			context.mozImageSmoothingEnabled = false;
			context.webkitImageSmoothingEnabled = false;
			context.msImageSmoothingEnabled = false;
			context.imageSmoothingEnabled = false;
			var dataUrl = canvas.toDataURL('image/jpeg', 1.0);
			var newImg = document.createElement("img");
			newImg.src = dataUrl;
			newImg.width = width;
			newImg.height = height;
			alert("截取成功，上拉查看图片");
			$("body")[0].appendChild(newImg);
		});
	})

至此，

整个页面就截取到了，可以保存到手机查看图片。