{"id":801,"date":"2021-09-08T16:36:36","date_gmt":"2021-09-08T08:36:36","guid":{"rendered":"http:\/\/www.wayln.com\/?p=801"},"modified":"2021-09-08T16:36:36","modified_gmt":"2021-09-08T08:36:36","slug":"%e5%bc%82%e6%ad%a5%e7%bc%96%e7%a8%8b%e5%9f%ba%e7%a1%80-%e5%88%9b%e5%bb%bavaluetask","status":"publish","type":"post","link":"https:\/\/www.wayln.com\/?p=801","title":{"rendered":"\u5f02\u6b65\u7f16\u7a0b\u57fa\u7840\u2014\u2014\u521b\u5efaValueTask"},"content":{"rendered":"<div id=\"toc_container\" class=\"toc_transparent no_bullets\"><p class=\"toc_title\">Contents<\/p><ul class=\"toc_list\"><li><a href=\"#i\"><span class=\"toc_number toc_depth_1\">1<\/span> \u95ee\u9898<\/a><\/li><li><a href=\"#i-2\"><span class=\"toc_number toc_depth_1\">2<\/span> \u89e3\u51b3\u65b9\u6848<\/a><\/li><li><a href=\"#i-3\"><span class=\"toc_number toc_depth_1\">3<\/span> \u8ba8\u8bba<\/a><\/li><\/ul><\/div>\n<h1><span id=\"i\">\u95ee\u9898<\/span><\/h1>\n<p>\u9700\u8981\u5b9e\u73b0\u4e00\u4e2a\u65b9\u6cd5\uff0c\u8ba9\u5b83\u8fd4\u56deValueTask&lt;T&#62;<\/p>\n<h1><span id=\"i-2\">\u89e3\u51b3\u65b9\u6848<\/span><\/h1>\n<p>\u5728\u6709\u540c\u6b65\u7ed3\u679c\u8fd4\u56de\u3001\u5f02\u6b65\u64cd\u4f5c\u8f83\u4e3a\u7f55\u89c1\u7684\u573a\u666f\u4e2d\uff0c\u53ef\u5c06ValueTask&lt;T&#62;\u7528\u4f5c\u4e00\u79cd\u8fd4\u56de\u7c7b\u578b\u3002\u8fd9\u91cc\u4e5f\u6709\u4e00\u6761\u51c6\u5219\uff0c\u90a3\u5c31\u662f\u5bf9\u4e8e\u81ea\u5199\u7684\u5e94\u7528\u7a0b\u5e8f\u4ee3\u7801\uff0c\u5e94\u5f53\u4f7f\u7528Task&lt;T&#62;\u4f5c\u4e3a\u8fd4\u56de\u7c7b\u578b\uff0c\u800c\u4e0d\u662f\u4f7f\u7528ValueTask&lt;T&#62;.\u5f53\u4e14\u4ec5\u5f53\u4f7f\u7528ValueTask&lt;T&#62;\u4f5c\u4e3a\u8fd4\u56de\u7c7b\u578b\u80fd\u591f\u63d0\u5347\u6027\u80fd\u65f6\uff0c\u624d\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u5b83\u3002\u56e0\u6b64\uff0c\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u9700\u8981\u5b9e\u73b0\u4e00\u79cd\u8fd4\u56deValueTask&lt;T&#62;\u7684\u65b9\u6cd5\u3002IAsyncDisposable\u5c31\u5c5e\u4e8e\u8fd9\u79cd\u60c5\u51b5\uff0c\u5b83\u7684DisposeAsync\u65b9\u6cd5\u4f1a\u8fd4\u56deValueTask<\/p>\n<pre><code class=\"language-CSharp line-numbers\">public async ValueTask&lt;int&gt; MethodAsync()\n{\n    await Task.Delay(100);\/\/\u5f02\u6b65\u5de5\u4f5c\n    return 13\uff1b\n}\n<\/code><\/pre>\n<p>\u5f88\u591a\u65f6\u5019\uff0c\u8fd4\u56deValueTask&lt;T&#62;\u7684\u65b9\u6cd5\u4e5f\u80fd\u7acb\u523b\u8fd4\u56de\u4e00\u4e2a\u503c\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4ee5\u4f7f\u7528ValueTask&lt;T&#62;\u6784\u9020\u51fd\u6570\u4f18\u5316\u8be5\u573a\u666f\uff0c\u7136\u540e\u5b50\u9700\u8981\u5728\u5fc5\u8981\u65f6\u53d1\u9001\u5230\u7f13\u6162\u7684\u5f02\u6b65\u65b9\u6cd5\u4e2d\uff1a<\/p>\n<pre><code class=\"language-CSharp line-numbers\">public ValueTask&lt;int&gt; MethodAsync()\n{\n    if(CanBehaveSynchronously)\n        return new ValueTask&lt;int&gt;(13);\n    return new ValueTask&lt;int&gt;(SlowMethodAsync());\n}\nprivate Task&lt;int&gt; SlowMethodAsync();\n<\/code><\/pre>\n<p>\u5bf9\u975e\u6cdb\u578b\u7684ValueTask\u800c\u8a00\uff0c\u8fd8\u6709\u4e2a\u7c7b\u4f3c\u7684\u53ef\u884c\u529e\u6cd5\uff0c\u6b64\u4f8b\u4e2d\u7684ValueTask\u9ed8\u8ba4\u6784\u9020\u51fd\u6570\u7528\u4ee5\u8fd4\u56de\u6210\u529f\u5b8c\u6210\u7684ValueTask.\u4e0b\u9762\u7684\u4f8b\u5b50\u5c55\u793a\u4e86\u4f7f\u7528IAsyncDisposable\u7684\u5b9e\u73b0\uff0c\u5176\u4e2d\u5f02\u6b65\u4e22\u5f03\u903b\u8f91\u53ea\u8fd0\u884c\u4e86\u4e00\u6b21\u3002\u5728\u4e4b\u540e\u7684\u8c03\u7528\u4e2d\uff0cDisposeAsync\u65b9\u6cd5\u9648\u5bab\u4e14\u540c\u6b65\u5730\u5b8c\u6210\u3002<\/p>\n<pre><code class=\"language-CSharp line-numbers\">private Func&lt;Task&gt; _disposeLogic;\npublic ValueTask DisposeAsync()\n{\n    if(_disposeLogic==null)\n        return default;\n    \/\/\u6ce8\u610f\uff0c\u8fd9\u4e2a\u7b80\u5355\u7684\u793a\u4f8b\u5bf9\u7ebf\u7a0b\u800c\u8a00\u5e76\u4e0d\u5b89\u5168\n    \/\/\u5982\u679c\u591a\u4e2a\u7ebf\u7a0b\u8c03\u7528DisposeAsync,\u90a3\u4e48\u8be5\u903b\u8f91\u53ef\u80fd\u4e0d\u6b62\u8fd0\u884c\u4e00\u6b21\n    Func&lt;Task&gt;logic=_disposeLogic;\n    _disposeLogic=null;\n    return new ValueTask(logic());\n}\n<\/code><\/pre>\n<h1><span id=\"i-3\">\u8ba8\u8bba<\/span><\/h1>\n<p>\u5927\u591a\u6570\u65b9\u6cd5\u5e94\u5f53\u8fd4\u56deTask&lt;T&#62;,\u8fd9\u662f\u56e0\u4e3a\u4f7f\u7528Task&lt;T&#62;\u7684\u9677\u9631\u4e0d\u53ca\u4f7f\u7528ValueTask&lt;T&#62;\u7684\u591a\u3002<br \/>\n\u5982\u679c\u53ea\u662f\u4f7f\u7528ValueTask\u6216ValueTask&lt;T&#62;\u6765\u5b9e\u73b0\u63a5\u53e3\uff0c\u90a3\u4e48\u53ef\u4ee5\u7b80\u5355\u7684\u4f7f\u7528async\u65b9\u6cd5\u548cawait\u65b9\u6cd5\u3002\u53ea\u6709\u5f53\u4f60\u60f3\u4f7f\u7528ValueTask&lt;T&#62;\u65f6\uff0c\u624d\u4f1a\u7528\u5230\u66f4\u9ad8\u9636\u7684\u5b9e\u73b0\u65b9\u5f0f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Contents1 \u95ee\u98982 \u89e3\u51b3\u65b9\u68483 \u8ba8\u8bba \u95ee\u9898 \u9700\u8981\u5b9e\u73b0\u4e00\u4e2a\u65b9\u6cd5\uff0c\u8ba9\u5b83\u8fd4\u56deValueTask&lt;T&#038;# [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,41,2],"tags":[],"class_list":["post-801","post","type-post","status-publish","format-standard","hentry","category-c","category-41","category-2"],"_links":{"self":[{"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/posts\/801","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wayln.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=801"}],"version-history":[{"count":1,"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/posts\/801\/revisions"}],"predecessor-version":[{"id":802,"href":"https:\/\/www.wayln.com\/index.php?rest_route=\/wp\/v2\/posts\/801\/revisions\/802"}],"wp:attachment":[{"href":"https:\/\/www.wayln.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=801"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wayln.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=801"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wayln.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=801"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}