{"id":2502,"date":"2018-02-12T14:22:46","date_gmt":"2018-02-12T06:22:46","guid":{"rendered":"http:\/\/www.xttblog.com\/?p=2502"},"modified":"2018-02-12T14:22:46","modified_gmt":"2018-02-12T06:22:46","slug":"failed-to-execute-getimagedata-on-canvasrenderingcontext2d-%e9%97%ae%e9%a2%98%e8%a7%a3%e5%86%b3%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=2502","title":{"rendered":"Failed to execute \u2018getImageData\u2019 on \u2018CanvasRenderingContext2D’ \u95ee\u9898\u89e3\u51b3\u65b9\u6cd5"},"content":{"rendered":"

\n\t\u6700\u8fd1\u5728\u4f7f\u7528 Canvas \u65f6\uff0c\u9047\u5230\u4e86\u8de8\u57df\u95ee\u9898\u3002\u672c\u6587\u4ecb\u7ecd\u5982\u4f55\u89e3\u51b3\u8fd9\u7c7b\u8de8\u57df\u95ee\u9898\u3002\n<\/p>\n

\n\t\u5177\u4f53\u7684\u9519\u8bef\u4fe1\u606f\u5982\u4e0b\uff1a\n<\/p>\n

\n

\n\t\tUncaught DOMException: Failed to execute ‘getImageData’ on ‘CanvasRenderingContext2D': The canvas has been tainted by cross-origin data.\n\t<\/p>\n<\/blockquote>\n

\n\t\u5bf9\u4e8e\u8de8\u57df\u7684\u56fe\u7247\uff0c\u53ea\u8981\u80fd\u591f\u5728\u7f51\u9875\u4e2d\u6b63\u5e38\u663e\u793a\u51fa\u6765\uff0c\u5c31\u53ef\u4ee5\u4f7f\u7528canvas\u7684drawImage() API\u7ed8\u5236\u51fa\u6765\u3002\u4f46\u662f\u5982\u679c\u4f60\u60f3\u66f4\u8fdb\u4e00\u6b65\uff0c\u901a\u8fc7getImageData()\u65b9\u6cd5\u83b7\u53d6\u56fe\u7247\u7684\u5b8c\u6574\u7684\u50cf\u7d20\u4fe1\u606f\uff0c\u5219\u591a\u534a\u4f1a\u51fa\u9519\u3002\n<\/p>\n

\n\t\u770b\u4e0b\u9762\u7684\u4e00\u4e2a\u4f8b\u5b50\uff1a\n<\/p>\n

\r\nvar canvas = document.createElement('canvas');\r\nvar context = canvas.getContext('2d');\r\n\/\/ \u4e1a\u4f59\u8349\uff1awww.xttblog.com\r\nvar img = new Image();\r\nimg.onload = function () {\r\n    context.drawImage(this, 0, 0);\r\n    context.getImageData(0, 0, this.width, this.height);\r\n};\r\nimg.src = 'https:\/\/avatars3.githubusercontent.com\/u\/496048?s=120&v=4';<\/pre>\n
\n\t\u8fd0\u884c\u540e\uff0cFirefox\u6d4f\u89c8\u5668\u9519\u8bef\u4e3a\uff1a\n<\/p>\n
\n
\n\t\tSecurityError: The operation is insecure.\n\t<\/p>\n<\/blockquote>\n
\n\t\u90a3\u6709\u6ca1\u6709\u4ec0\u4e48\u529e\u6cd5\u53ef\u4ee5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u5462\uff1f\n<\/p>\n
\n\t\u5728HTML5\u4e2d\uff0c\u6709\u4e9b\u5143\u7d20\u63d0\u4f9b\u4e86\u652f\u6301CORS(Cross-Origin Resource Sharing)\uff08\u8de8\u57df\u8d44\u6e90\u5171\u4eab\uff09\u7684\u5c5e\u6027\uff0c\u8fd9\u4e9b\u5143\u7d20\u5305\u62ec<img>\uff0c<video>\uff0c<script>\u7b49\uff0c\u800c\u63d0\u4f9b\u7684\u5c5e\u6027\u540d\u5c31\u662fcrossOrigin\u5c5e\u6027\u3002\n<\/p>\n
\n\t\u56e0\u6b64\uff0c\u4e0a\u9762\u7684\u8de8\u57df\u95ee\u9898\u53ef\u4ee5\u8fd9\u4e48\u5904\u7406\uff1a\n<\/p>\n
\r\nvar canvas = document.createElement('canvas');\r\nvar context = canvas.getContext('2d');\r\n\/\/ \u4e1a\u4f59\u8349\uff1awww.xttblog.com\r\nvar img = new Image();\r\nimg.crossOrigin = '';\r\nimg.onload = function () {\r\n    context.drawImage(this, 0, 0);\r\n    context.getImageData(0, 0, this.width, this.height);\r\n};\r\nimg.src = 'https:\/\/avatars3.githubusercontent.com\/u\/496048?s=120&v=4';<\/pre>\n
\n\t\u589e\u52a0\u4e00\u4e2aimg.crossOrigin = ''\u5373\u53ef\uff0c\u867d\u7136JS\u4ee3\u7801\u8fd9\u91cc\u8bbe\u7f6e\u7684\u662f\u7a7a\u5b57\u7b26\u4e32\uff0c\u5b9e\u9645\u4e0a\u8d77\u4f5c\u7528\u7684\u5c5e\u6027\u503c\u662fanonymous\u3002\n<\/p>\n
\n\tcrossOrigin\u53ef\u4ee5\u6709\u4e0b\u9762\u4e24\u4e2a\u503c\uff1a\n<\/p>\n\n\n\n\n\n\n
\n\t\t\t\t\u5173\u952e\u5b57\n\t\t\t<\/th>\n\n\t\t\t\t\u91ca\u4e49\n\t\t\t<\/th>\n<\/tr>\n<\/thead>\n
\n\t\t\t\tanonymous\n\t\t\t<\/td>\n\n\t\t\t\t\u5143\u7d20\u7684\u8de8\u57df\u8d44\u6e90\u8bf7\u6c42\u4e0d\u9700\u8981\u51ed\u8bc1\u6807\u5fd7\u8bbe\u7f6e\u3002\n\t\t\t<\/td>\n<\/tr>\n
\n\t\t\t\tuse-credentials\n\t\t\t<\/td>\n\n\t\t\t\t\u5143\u7d20\u7684\u8de8\u57df\u8d44\u6e90\u8bf7\u6c42\u9700\u8981\u51ed\u8bc1\u6807\u5fd7\u8bbe\u7f6e\uff0c\u610f\u5473\u7740\u8be5\u8bf7\u6c42\u9700\u8981\u63d0\u4f9b\u51ed\u8bc1\u3002\n\t\t\t<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\t\u5176\u4e2d\uff0c\u53ea\u8981crossOrigin\u7684\u5c5e\u6027\u503c\u4e0d\u662fuse-credentials\uff0c\u5168\u90e8\u90fd\u4f1a\u89e3\u6790\u4e3aanonymous\uff0c\u5305\u62ec\u7a7a\u5b57\u7b26\u4e32\uff0c\u5305\u62ec\u7c7b\u4f3c'xttblog'\u8fd9\u6837\u7684\u5b57\u7b26\u3002\n<\/p>\n
\n\t\u4f8b\u5982\uff1a\n<\/p>\n
\r\nimg.crossOrigin = 'xttblog';\r\nconsole.log(img.crossOrigin);\/\/ \u7ed3\u679c\u662f'anonymous'<\/pre>\n
\n\t\u53e6\u5916\u8fd8\u6709\u4e00\u70b9\u9700\u8981\u6ce8\u610f\uff0c\u90a3\u5c31\u662f\u867d\u7136\u6ca1\u6709crossOrigin\u5c5e\u6027\uff0c\u548c\u8bbe\u7f6ecrossOrigin="use-credentials"\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u90fd\u4f1a\u62a5\u8de8\u57df\u51fa\u9519\uff0c\u4f46\u662f\u6027\u8d28\u4e0a\u5374\u4e0d\u4e00\u6837\uff0c\u4e24\u8005\u6709\u8f83\u5927\u533a\u522b\u3002\n<\/p>\n
\n\tIE11+\uff0cSafari\uff0cChrome\uff0cFirefox\u6d4f\u89c8\u5668\u5747\u652f\u6301\uff0cIE9\u548cIE10\u4f1a\u62a5SecurityError\u5b89\u5168\u9519\u8bef\u3002<\/p>\n
\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/<\/p>
\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1axttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p>
\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a\u4e1a\u4f59\u8349<\/a>\uff1a » Failed to execute \u2018getImageData\u2019 on \u2018CanvasRenderingContext2D’ \u95ee\u9898\u89e3\u51b3\u65b9\u6cd5<\/a><\/p>","protected":false},"excerpt":{"rendered":"
\u6700\u8fd1\u5728\u4f7f\u7528 Canvas \u65f6\uff0c\u9047\u5230\u4e86\u8de8\u57df\u95ee\u9898\u3002\u672c\u6587\u4ecb\u7ecd\u5982\u4f55\u89e3\u51b3\u8fd9\u7c7b\u8de8\u57df\u95ee\u9898\u3002 \u5177\u4f53\u7684\u9519\u8bef\u4fe1\u606f\u5982\u4e0b\uff1a Uncau […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[31,1601,1602,54],"class_list":["post-2502","post","type-post","status-publish","format-standard","hentry","category-html5","tag-canvas","tag-crossorigin","tag-getimagedata","tag-html2canvas"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/2502","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2502"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/2502\/revisions"}],"predecessor-version":[{"id":2503,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/2502\/revisions\/2503"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2502"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2502"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2502"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}