{"id":2124,"date":"2015-03-12T10:37:40","date_gmt":"2015-03-12T02:37:40","guid":{"rendered":"http:\/\/blog.qdac.cc\/?p=2124"},"modified":"2015-03-12T10:37:40","modified_gmt":"2015-03-12T02:37:40","slug":"qdataset-%e7%9a%84-locate-%e7%b3%bb%e5%88%97%e5%87%bd%e6%95%b0%e4%bd%bf%e7%94%a8%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/blog.qdac.cc\/?p=2124","title":{"rendered":"QDataSet \u7684 Locate \u7cfb\u5217\u51fd\u6570\u4f7f\u7528\u8be6\u89e3"},"content":{"rendered":"<p>QDataSet \u589e\u5f3a\u4e86 TDataSet \u7684 Locate \u529f\u80fd\uff0c\u4ee5\u65b9\u4fbf\u5927\u5bb6\u4f7f\u7528\u3002\u4e0e TDataSet \u76f8\u6bd4\uff0cQDataSet \u63d0\u4f9b\u7684\u662f\u4e00\u7ec4 LocateXXX \uff0c\u6211\u4eec\u5728\u6b64\u505a\u4e00\u4e2a\u4ecb\u7ecd\uff0c\u9996\u5148\u6765\u770b\u4e00\u4e0b\u51fd\u6570\u58f0\u660e\uff1a<\/p>\n<pre class=\"lang:delphi decode:true \">    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u4e0b\u4e00\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function Locate(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions): Boolean; override;\r\n    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u4e0b\u4e00\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"ARestart\"&gt; \u662f\u5426\u91cd\u65b0\u5f00\u59cb\u5b9a\u4f4d&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"AGoBack\"&gt; \u662f\u5426\u5f80\u56de\u67e5\u627e&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function LocateEx(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions; ARestart, AGoBack: Boolean): Boolean;\r\n    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u9996\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function LocateFirst(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions): Boolean;\r\n    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u4e0b\u4e00\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function LocateNext(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions): Boolean;\r\n    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u4e0a\u4e00\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function LocatePrior(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions): Boolean;\r\n    \/\/\/&lt;summary&gt;\u5b9a\u4f4d\u5230\u6700\u540e\u4e00\u6761\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55&lt;\/summary&gt;\r\n    \/\/\/&lt;param name=\"KeyFields\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u5217\u8868\uff0c\u4e2d\u95f4\u4ee5\",\"\u6216\";\"\u5206\u9694&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"KeyValues\"&gt; \u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\u7684\u5173\u952e\u503c\u5217\u8868&lt;\/param&gt;\r\n    \/\/\/&lt;param name=\"Options\"&gt; \u5b9a\u4f4d\u7684\u9009\u9879&lt;\/param&gt;\r\n    \/\/\/&lt;returns&gt;\u6210\u529f\uff0c\u79fb\u52a8\u5230\u6307\u5b9a\u7684\u8bb0\u5f55\u5e76\u8fd4\u56deTrue\uff0c\u5426\u5219\uff0c\u8fd4\u56deFalse&lt;\/returns&gt;\r\n    function LocateLast(const KeyFields: string; const KeyValues: Variant;\r\n      Options: TLocateOptions): Boolean;<\/pre>\n<p>\u6807\u51c6\u7684 Locate \u51fd\u6570\u54b1\u4eec\u5c31\u4e0d\u52a0\u4ee5\u7f00\u8ff0\u4e86\uff0c\u73b0\u5728\u4ecb\u7ecd\u4e0b\u589e\u5f3a\u7684\u51fd\u6570\uff1a<\/p>\n<ul>\n<li>LocateEx<\/li>\n<\/ul>\n<p>\u8fd9\u4e2a\u51fd\u6570\u52a0\u5165\u4e86\u4e24\u4e2a\u53c2\u6570 ARestart \u548c AGoback \u53c2\u6570\u3002\u5176\u4e2d ARestart \u4e3a True \u65f6\uff0c\u5982\u679c AGoBack \u4e3a True \uff0c\u5219\u4ece\u6700\u540e\u4e00\u6761\u5f00\u59cb\u91cd\u65b0\u5411\u524d\u67e5\u627e\u5b9a\u4f4d\uff0c\u5982\u679c AGoBack \u4e3a False\uff0c\u5219\u4ece\u7b2c\u4e00\u6761\u5f00\u59cb\u91cd\u65b0\u5411\u540e\u5b9a\u4f4d\u3002\u5982\u679c ARestart \u4e3a False\uff0c\u5219 AGoBack \u4ece\u4e0a\u4e00\u6761\u5f00\u59cb\u5411\u524d\u5b9a\u4f4d\uff0c\u5426\u5219\u4ece\u4e0b\u4e00\u6761\u5f00\u59cb\u5411\u540e\u5b9a\u4f4d\u3002\u5176\u5b9e LocateFirst \/ LocateNext \/ LocatePrior \/ LocateLast \u00a0\u4e0d\u8fc7\u662f\u6b64\u51fd\u6570\u7684\u7b80\u5355\u5c01\u88c5\u3002<\/p>\n<ul>\n<li>LocateFirst<\/li>\n<\/ul>\n<p>\u7b49\u4ef7\u4e8e\u00a0LocateEx(KeyFields, KeyValues, Options, True, false)\u3002<\/p>\n<ul>\n<li>LocateNext<\/li>\n<\/ul>\n<p>\u7b49\u4ef7\u4e8e\u00a0LocateEx(KeyFields, KeyValues, Options, false, false);<\/p>\n<ul>\n<li>LocatePrior<\/li>\n<\/ul>\n<p>\u7b49\u4ef7\u4e8e LocateEx(KeyFields, KeyValues, Options, false, True);<\/p>\n<ul>\n<li>LocateLast<\/li>\n<\/ul>\n<p>\u7b49\u4ef7\u4e8eLocateEx(KeyFields, KeyValues, Options, True, True);<\/p>\n<p>\u5177\u4f53\u7684\u51fd\u6570\u7684\u7528\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u53c2\u8003 QDSLocate \u793a\u4f8b\u7a0b\u5e8f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>QDataSet \u589e\u5f3a\u4e86 TDataSe [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[69,8,9,66],"tags":[350],"class_list":["post-2124","post","type-post","status-publish","format-standard","hentry","category-c-builder","category-delphi","category-qdac","category-qdb","tag-locate"],"views":3143,"_links":{"self":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/2124","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2124"}],"version-history":[{"count":1,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/2124\/revisions"}],"predecessor-version":[{"id":2125,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/2124\/revisions\/2125"}],"wp:attachment":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}