js \u56fe\u7247 \u538b\u7f29 \u56fe\u7247 js<\/p>\n
function dealImage(base64, w, callback) {\r\n var newImage = new Image();\r\n var quality = 0.6; \/\/\u538b\u7f29\u7cfb\u65700-1\u4e4b\u95f4\r\n newImage.src = base64;\r\n newImage.setAttribute(\"crossOrigin\", 'Anonymous'); \/\/url\u4e3a\u5916\u57df\u65f6\u9700\u8981\r\n var imgWidth, imgHeight;\r\n newImage.onload = function () {\r\n imgWidth = this.width;\r\n imgHeight = this.height;\r\n var canvas = document.createElement(\"canvas\");\r\n var ctx = canvas.getContext(\"2d\");\r\n if (Math.max(imgWidth, imgHeight) > w) {\r\n if (imgWidth > imgHeight) {\r\n canvas.width = w;\r\n canvas.height = w * imgHeight \/ imgWidth;\r\n } else {\r\n canvas.height = w;\r\n canvas.width = w * imgWidth \/ imgHeight;\r\n }\r\n } else {\r\n canvas.width = imgWidth;\r\n canvas.height = imgHeight;\r\n quality = 0.6;\r\n }\r\n ctx.clearRect(0, 0, canvas.width, canvas.height);\r\n ctx.drawImage(this, 0, 0, canvas.width, canvas.height);\r\n var base64 = canvas.toDataURL(\"image\/jpeg\", quality); \/\/\u538b\u7f29\u8bed\u53e5\r\n \/\/ \u5982\u60f3\u786e\u4fdd\u56fe\u7247\u538b\u7f29\u5230\u81ea\u5df1\u60f3\u8981\u7684\u5c3a\u5bf8,\u5982\u8981\u6c42\u572850-150kb\u4e4b\u95f4\uff0c\u8bf7\u52a0\u4ee5\u4e0b\u8bed\u53e5\uff0cquality\u521d\u59cb\u503c\u6839\u636e\u60c5\u51b5\u81ea\u5b9a\r\n \/\/ while (base64.length \/ 1024 > 150) {\r\n \/\/ quality -= 0.01;\r\n \/\/ base64 = canvas.toDataURL(\"image\/jpeg\", quality);\r\n \/\/ }\r\n \/\/ \u9632\u6b62\u6700\u540e\u4e00\u6b21\u538b\u7f29\u4f4e\u4e8e\u6700\u4f4e\u5c3a\u5bf8\uff0c\u53ea\u8981quality\u9012\u51cf\u5408\u7406\uff0c\u65e0\u9700\u8003\u8651\r\n \/\/ while (base64.length \/ 1024 < 50) {\r\n \/\/ quality += 0.001;\r\n \/\/ base64 = canvas.toDataURL(\"image\/jpeg\", quality);\r\n \/\/ }\r\n callback(base64);\/\/\u5fc5\u987b\u901a\u8fc7\u56de\u8c03\u51fd\u6570\u8fd4\u56de\uff0c\u5426\u5219\u65e0\u6cd5\u53ca\u65f6\u62ff\u5230\u8be5\u503c\r\n }\r\n}\r\n\r\n\r\n\r\n\/\/\u8fd9\u662f\u539f\u6765\u7684base64\u683c\u5f0f\u5b57\u7b26\u4e32\r\nvar base64= path;\r\n\/\/\u8fd9\u5c31\u662f\u4f60\u538b\u7f29\u4e4b\u540e\u7684\u5b57\u7b26\u4e32\r\nvar str;\r\n\/\/\u4f60\u53ef\u4ee5\u6253\u6869\u770b\u4e00\u4e0b\u6709\u591a\u957f\r\nconsole.log(base64.length);\r\n\/\/\u7136\u540e\u8c03\u7528\u538b\u7f29\u65b9\u6cd5 \u7b2c\u4e00\u4e2a\u53c2\u6570\u5c31\u662f\u539f\u6765\u7684\u5b57\u7b26\u4e32\uff0c\u7b2c\u4e8c\u4e2a\u662f\u5bbd\u5ea6\uff0c\u7b2c\u4e09\u4e2a\u5c31\u662f\u56de\u8c03\u65b9\u6cd5\uff0c\u4e5f\u5c31\u662f\u538b\u7f29\u51fd\u6570\u6700\u540e\u9762\u90a3\u4e2acallback\uff08base64\uff09\r\ndealImage(base64, 500, useImg);\r\n\/\/\u7136\u540e\u4e00\u538b \u518d\u6253\u4e2a\u6869\u770b\u4e0b\u957f\u5ea6 \u65b9\u6cd5\u540d\u968f\u4fbf\u8d77\u600e\u4e48\u8212\u670d\u600e\u4e48\u6765\r\nfunction useImg(base64) {\r\n str= base64;\r\n console.log(str.length);\r\n}<\/pre>\n <\/p>\n