canvas转换为dataURL (从canvas获取dataURL) var dataurl = canvas.toDataURL('image/png'); var dataurl2 = canvas.toDataURL('image/jpeg', 0.8); File对象转换为dataURL.Blob对象转换为dataURL File对象也是一个Blob对象,二者的处理相同. function readBlobAsDataURL(blob, callback) { var a = new
用于上传图片的js验证: <%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd&q