{"id":563,"date":"2011-06-06T11:56:52","date_gmt":"2011-06-06T03:56:52","guid":{"rendered":"http:\/\/leybreeze.com\/blog\/?p=563"},"modified":"2011-06-08T14:21:06","modified_gmt":"2011-06-08T06:21:06","slug":"android%e5%a6%82%e4%bd%95%e7%bb%98%e5%88%b6%e8%a7%86%e5%9b%be","status":"publish","type":"post","link":"http:\/\/leybreeze.com\/blog\/?p=563","title":{"rendered":"Android\u5982\u4f55\u7ed8\u5236\u89c6\u56fe"},"content":{"rendered":"<p>\u5f53\u4e00\u4e2aActivity\u63a5\u6536\u5230\u7126\u70b9\u65f6\uff0c\u5b83\u5c06\u88ab\u8bf7\u6c42\u7ed8\u5236\u5176\u5e03\u5c40\uff08layout\uff09\u3002Android\u6846\u67b6\u5c06\u5904\u7406\u8fd9\u4e2a\u7ed8\u5236\u8fc7\u7a0b\uff0c\u540c\u65f6Activity\u5fc5\u987b\u63d0\u4f9b\u5176\u5e03\u5c40\u5c42\u7ea7\u7684\u6839\u8282\u70b9\u3002<\/p>\n<p>\u7ed8\u5236\u8fc7\u7a0b\u4ece\u5e03\u5c40\u7684\u6839\u8282\u70b9\u5f00\u59cb\u3002\u5b83\u88ab\u8bf7\u6c42\u6d4b\u91cf\u5e76\u7ed8\u5236\u5e03\u5c40\u6811\u3002\u7ed8\u5236\u8fc7\u7a0b\u901a\u8fc7\u904d\u5386\u5e03\u5c40\u6811\u5e76\u6e32\u67d3\u6bcf\u4e00\u4e2a\u7a7f\u63d2\u4e8einvalid\u533a\u57dfView\u8fdb\u884c\u3002\u6bcf\u4e00\u4e2a\u89c6\u56fe\u7ec4\u987a\u6b21\u8d1f\u8d23\u8bf7\u6c42\u5176\u6bcf\u4e00\u4e2a\u5b50\u89c6\u56fe\u8fdb\u884c\u7ed8\u5236\uff08\u4ee5draw()\u65b9\u6cd5\uff09\uff0c\u800c\u6bcf\u4e00\u4e2aView\u5219\u8d1f\u8d23\u7ed8\u5236\u81ea\u8eab\u3002\u56e0\u4e3a\u5e03\u5c40\u6811\u662f\u4f9d\u6b21\u904d\u5386\u7684\uff0c\u8fd9\u5c31\u610f\u5473\u7740\u7236\u89c6\u56fe\u5c06\u5728\u5176\u5b50\u89c6\u56fe\u4e4b\u524d\uff08\u5373\u4f4d\u4e8e\u5176\u4e0b\u65b9\uff09\u88ab\u7ed8\u5236\uff0c\u800c\u5144\u5f1f\u89c6\u56fe\u6839\u636e\u5176\u51fa\u73b0\u5728\u6570\u4e2d\u7684\u4f4d\u7f6e\u6309\u987a\u5e8f\u88ab\u7ed8\u5236\u3002<\/p>\n<p>\u7ed8\u5236\u5e03\u5c40\u662f\u4e00\u4e2a\u5206\u4e3a\u4e24\u6761\u7ebf\u8def\u7684\u8fc7\u7a0b\uff1a\u6d4b\u91cf\u7ebf\u8def\uff08measuring pass\uff09\u548c\u5e03\u5c40\u7ebf\u8def\uff08layout pass\uff09\u3002\u6d4b\u91cf\u7ebf\u8def\u7531measure(int ,int)\u5b8c\u6210\uff0c\u662f\u89c6\u56fe\u6811\u7684\u4e00\u6b21\u4ece\u4e0a\u81f3\u4e0b\u7684\u904d\u5386\u3002\u5728\u9012\u5f52\u8fc7\u7a0b\u4e2d\u6bcf\u4e00\u4e2aView\u6cbf\u7740\u6811\u5411\u4e0b\u63a8\u9001\u5b83\u7684\u5c3a\u5bf8\u3002\u5728\u6d4b\u91cf\u7ebf\u8def\u7684\u6700\u540e\uff0c\u6bcf\u4e00\u4e2aView\u5c31\u90fd\u5df2\u50a8\u5b58\u4e86\u5176\u6d4b\u91cf\u5c3a\u5bf8\u503c\u3002\u7b2c\u4e8c\u6761\u7ebf\u8def\u5728layout(int, int, int, int)\u4e2d\u5b8c\u6210\uff0c\u5b83\u540c\u6837\u4e5f\u662f\u81ea\u4e0a\u800c\u4e0b\u7684\u3002\u5728\u8fd9\u4e2a\u7ebf\u8def\u4e2d\u7236\u89c6\u56fe\u8d1f\u8d23\u901a\u8fc7\u5728\u6d4b\u91cf\u7ebf\u8def\u4e2d\u8ba1\u7b97\u5f97\u5230\u7684\u5c3a\u5bf8\u6765\u5b9a\u4f4d\u5176\u6240\u6709\u7684\u5b50\u89c6\u56fe\u3002<\/p>\n<p style=\"padding-left: 30px;\">Android\u6846\u67b6\u4e0d\u5141\u8bb8\u7ed8\u5236\u4e0d\u5728invalid\u533a\u57df\u5185\u7684View\uff0c\u540c\u65f6\u5b83\u5c06\u8d1f\u8d23\u7ed8\u5236View\u7684\u80cc\u666f\u3002<\/p>\n<p style=\"padding-left: 30px;\">\u53ef\u4ee5\u901a\u8fc7\u8c03\u7528invalidate()\u6765\u5f3a\u5236\u7ed8\u5236\u4e00\u4e2aView\u3002<\/p>\n<p>\u5f53\u4e00\u4e2aView\u7684<span style=\"color: #008000;\">measure<\/span>()\u65b9\u6cd5\u8fd4\u56de\u65f6\uff0c\u5fc5\u987b\u8bbe\u5b9a\u5b83\u4e0e\u5b83\u7684\u5b50\u5b59\u7c7b\u7684getMeasuredWidth()\u548cgetMeasuredHeight()\u503c\u3002\u4e00\u4e2aView\u7684\u6d4b\u91cf\u5bbd\u5ea6\u548c\u6d4b\u91cf\u9ad8\u5ea6\u5fc5\u987b\u6ee1\u8db3\u5176\u7236\u7c7b\u7684\u7ea6\u675f\u3002\u8fd9\u4fdd\u8bc1\u4e86\u5728\u6d4b\u91cf\u7ebf\u8def\u7684\u6700\u540e\uff0c\u6240\u6709\u7684\u7236\u7c7b\u53ef\u4ee5\u7b26\u5408\u6240\u6709\u5b50\u7c7b\u7684\u6d4b\u91cf\u503c\u3002\u4e00\u4e2a\u7236\u7c7bView\u53ef\u4ee5\u4e0d\u6b62\u4e00\u6b21\u5bf9\u5176\u5b50\u7c7b\u8c03\u7528<span style=\"color: #008000;\">measure<\/span>()\u3002\u4f8b\u5982\uff0c\u7236\u7c7b\u53ef\u4ee5\u4ee5\u672a\u6307\u5b9a\u7684\u5c3a\u5bf8\u6765\u6d4b\u91cf\u6bcf\u4e00\u4e2a\u5b50\u7c7b\u4ee5\u786e\u5b9a\u4ed6\u4eec\u6240\u9700\u7684\u5c3a\u5bf8\uff0c\u4e4b\u540e\u4ee5\u5b9e\u9645\u503c\u5bf9\u5176\u518d\u6b21\u8c03\u7528measure()\u6765\u68c0\u67e5\u6240\u6709\u5b50\u7c7b\u7684\u672a\u7ea6\u675f\u7684\u5c3a\u5bf8\u662f\u5426\u8fc7\u5927\u6216\u662f\u8fc7\u5c0f\u3002\uff08\u5373\uff0c\u5982\u679c\u5b50\u7c7b\u548c\u5176\u5e94\u8be5\u5360\u7528\u7684\u5c3a\u5bf8\u4e0d\u7b26\uff0c\u7236\u7c7b\u5c06\u4f1a\u8fdb\u884c\u5e72\u9884\uff0c\u5c06\u89c4\u5219\u8bbe\u7f6e\u4e3a\u7b2c\u4e8c\u6761\u7ebf\u8def\uff09\u3002\u3010\u62b1\u6b49\u8fd9\u90e8\u5206\u7ffb\u8bd1\u8d28\u91cf\u6b20\u4f73\uff0c\u4e4b\u540e\u4f1a\u627e\u65f6\u95f4\u8003\u8651\u5982\u4f55\u6539\u8fdb\uff08\u5176\u5b9e\u5f88\u591a\u90e8\u5206\u7ffb\u8bd1\u8d28\u91cf\u90fd\u9700\u8981\u63d0\u9ad8\uff0c\u603b\u4e4b\u73b0\u5728\u5148\u5b8c\u6210\u7b2c\u4e00\u904d\u518d\u8bf4\u4e86\u3002\u6e10\u6e10\u5f00\u59cb\u7406\u89e3\u90a3\u4e9b\u4e2d\u6587\u7248\u6559\u6750\u4ee4\u4eba\u65e0\u6cd5\u6ee1\u610f\u7684\u7ffb\u8bd1\u80cc\u540e\u7684\u7ffb\u8bd1\u8005\u4e86\u2026\u2026\uff09\u3011<\/p>\n<p>\u6d4b\u91cf\u7ebf\u8def\u4f7f\u7528\u4e24\u4e2a\u7c7b\u6765\u4ea4\u6d41\u5c3a\u5ea6\u3002View.MeasureSpec\u7c7b\u88abView\u7528\u6765\u544a\u8bc9\u5176\u7236\u7c7b\u5e0c\u671b\u88ab\u6d4b\u91cf\u548c\u5b9a\u4f4d\u7684\u60c5\u51b5\u3002\u57fa\u672c\u7684LayoutParams\u7c7b\u7528\u6765\u63cf\u8ff0View\u6240\u5e0c\u671b\u7684\u9ad8\u5bbd\u5c3a\u5bf8\u3002\u5bf9\u4e8e\u6bcf\u4e00\u4e2a\u7ef4\u5ea6\uff0c\u53ef\u4ee5\u6307\u5b9a\u4ee5\u4e0b\u4e4b\u4e00\uff1a<\/p>\n<ul>\n<li>\u4e00\u4e2a\u786e\u5207\u7684\u6570\u5b57<\/li>\n<li><em><span style=\"color: #008000;\">FILL_PARENT<\/span><\/em> \u8868\u793aView\u5e0c\u671b\u548c\u5176\u7236\u7c7b\u4e00\u6837\u5927\uff08\u51cf\u53bb\u95f4\u9699\uff09<\/li>\n<li><em><span style=\"color: #008000;\">WRAP_CONTENT <\/span><\/em> \u8868\u793aView\u5e0c\u671b\u5176\u5927\u5c0f\u8db3\u4ee5\u5305\u542b\u5176\u5185\u5bb9\uff08\u52a0\u4e0a\u95f4\u9699\uff09\u3002<\/li>\n<\/ul>\n<p style=\"padding-left: 30px;\">\u8981\u5b9e\u4f8b\u5316\u4e00\u4e2a\u5e03\u5c40\uff0c\u9700\u8981\u8c03\u7528requestLayout()\u3002\u8be5\u65b9\u6cd5\u4e5f\u5c06\u5728\u4e00\u4e2aView\u8ba4\u4e3a\u81ea\u8eab\u4e0d\u53ef\u80fd\u9002\u5408\u5f53\u524d\u8fb9\u6846\u65f6\u81ea\u8c03\u7528\u3002<\/p>\n<p>\u5bf9\u4e8eViewGroup\u7684\u4e0d\u540c\u5b50\u7c7b\u6709\u76f8\u5bf9\u5e94\u7684LayoutParams\u7684\u5b50\u7c7b\u3002\u4e3d\u65e5\uff0cRelativeLayout\u6709\u5176\u4e13\u5c5e\u7684LayoutParams\u5b50\u7c7b\uff0c\u5b83\u53ef\u4ee5\u6c34\u5e73\u53ca\u5782\u76f4\u5b9a\u4f4d\u5176\u5b50\u89c6\u56fe\u3002<\/p>\n<p>MeasureSpec\u7528\u4e8e\u5c06\u9700\u6c42\u6cbf\u7740\u5e03\u5c40\u6811\u4ece\u7236\u81f3\u5b50\u5411\u4e0b\u63a8\u9001\u3002\u4e00\u4e2aMeasureSpec\u53ef\u4ee5\u4ee5\u4e0b\u4e09\u79cd\u6a21\u5f0f\u5b58\u5728\uff1a<\/p>\n<ul>\n<li><em><span style=\"color: #008000;\">UNSPECIFIED<\/span><\/em>: \u8fd9\u88ab\u7236\u7c7b\u7528\u4e8e\u51b3\u5b9a\u67d0\u4e00\u5b50\u89c6\u56fe\u7684\u671f\u671b\u5c3a\u5ea6\u3002\u4f8b\u5982\uff0c\u4e00\u4e2aLineraLayout\u53ef\u4ee5\u5bf9\u5176\u5b50\u7c7b\u8c03\u7528<span style=\"color: #008000;\">measure<\/span>()\uff0c\u5c06\u9ad8\u5ea6\u8bbe\u7f6e\u4e3a<em><span style=\"color: #008000;\">UNSPECIFIED<\/span><\/em>\uff0c\u5bbd\u5ea6\u8bbe\u7f6e\u4e3a<em><span style=\"color: #008000;\">EXACTLY <\/span><\/em>240\u4ee5\u786e\u5b9a\u8be5\u5b50\u7c7b\u5728\u88ab\u5206\u914d\u4e86240\u50cf\u7d20\u5bbd\u5ea6\u65f6\u6240\u9700\u7684\u9ad8\u5ea6\u662f\u591a\u5c11\u3002<\/li>\n<li><em><span style=\"color: #008000;\">EXACTLY<\/span><\/em>: \u8fd9\u88ab\u7236\u7c7b\u7528\u4e8e\u5f3a\u5236\u8bbe\u7f6e\u5176\u5b50\u7c7b\u7684\u786e\u5207\u5c3a\u5bf8\u3002\u5b50\u7c7b\u5fc5\u987b\u4f7f\u7528\u8be5\u5c3a\u5bf8\uff0c\u4e14\u4fdd\u8bc1\u5b83\u7684\u6240\u6709\u5b50\u55e3\u4e5f\u90fd\u6ee1\u8db3\u8fd9\u4e2a\u5c3a\u5bf8\u9650\u5b9a\u3002<\/li>\n<li><em><span style=\"color: #008000;\">AT_MOST<\/span><\/em>: \u8fd9\u88ab\u7236\u7c7b\u7528\u8bed\u5f3a\u5236\u8bbe\u7f6e\u5176\u5b50\u7c7b\u7684\u6700\u5927\u5c3a\u5bf8\u3002\u5b50\u7c7b\u5fc5\u987b\u4fdd\u8bc1\u5b83\u53ca\u5176\u5b50\u55e3\u6ee1\u8db3\u8be5\u5c3a\u5bf8\u3002<\/li>\n<\/ul>\n<p><a title=\"\u7528\u6237\u754c\u9762\" href=\"http:\/\/leybreeze.com\/blog\/?p=117\">\u8fd4\u56de\u201c\u7528\u6237\u754c\u9762\u201d<\/a><\/p>\n<p>\u672c\u4f5c\u54c1\u91c7\u7528<a title=\"\u77e5\u8bc6\u5171\u4eab \u7f72\u540d-\u975e\u5546\u4e1a\u6027\u4f7f\u7528-\u7981\u6b62\u6f14\u7ece 3.0 Unported\u8bb8\u53ef\u534f\u8bae\" rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/\" target=\"_blank\">\u77e5\u8bc6\u5171\u4eab \u7f72\u540d-\u975e\u5546\u4e1a\u6027\u4f7f\u7528-\u7981\u6b62\u6f14\u7ece 3.0 Unported\u8bb8\u53ef\u534f\u8bae<\/a>\u8fdb\u884c\u8bb8\u53ef\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5f53\u4e00\u4e2aActivity\u63a5\u6536\u5230\u7126\u70b9\u65f6\uff0c\u5b83\u5c06\u88ab\u8bf7\u6c42\u7ed8\u5236\u5176\u5e03\u5c40\uff08layout\uff09\u3002Android\u6846\u67b6\u5c06\u5904\u7406\u8fd9\u4e2a\u7ed8\u5236\u8fc7\u7a0b &hellip; <a href=\"http:\/\/leybreeze.com\/blog\/?p=563\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201cAndroid\u5982\u4f55\u7ed8\u5236\u89c6\u56fe\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,10],"tags":[5,18],"_links":{"self":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/563"}],"collection":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=563"}],"version-history":[{"count":5,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/563\/revisions"}],"predecessor-version":[{"id":576,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/563\/revisions\/576"}],"wp:attachment":[{"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=563"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/leybreeze.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}