{"id":653,"date":"2025-03-17T01:56:46","date_gmt":"2025-03-17T01:56:46","guid":{"rendered":"https:\/\/boochlin.com\/?p=653"},"modified":"2026-09-19T17:04:03","modified_gmt":"2026-09-19T17:04:03","slug":"modifier-%e6%95%88%e8%83%bd-draw-%e5%95%a5%e6%af%94%e8%bc%83%e5%a5%bd%ef%bc%9adrawbehind-drawwithcontent","status":"publish","type":"post","link":"https:\/\/boochlin.com\/?p=653","title":{"rendered":"Modifier \u6548\u80fd Draw \u5565\u6bd4\u8f03\u597d\uff1adrawBehind , drawWithContent,drawWithCache"},"content":{"rendered":"<p>Compose \u7684\u81ea\u8a02\u7e6a\u5716\u662f\u6548\u80fd\u6bba\u624b\u3002\u6bcf\u6b21\u756b\u9762\u91cd\u7d44\uff0c\u4f60\u7684\u7e6a\u5716\u908f\u8f2f\u5c31\u5f97\u91cd\u8dd1\u4e00\u6b21\uff0cFPS \u96a8\u6642\u53ef\u80fd\u5d29\u76e4\u3002<\/p>\n<h4>1. Modifier.drawBehind\uff1a\u80cc\u666f\u677f<\/h4>\n<p>\u5b83\u6703\u5148\u8b93\u4f60\u756b\u5716\uff0c<strong>\u7136\u5f8c<\/strong>\u624d\u628a\u5143\u4ef6\u5167\u5bb9\uff08\u6587\u5b57\u3001\u5716\u7247\uff09\u756b\u4e0a\u53bb\u3002<\/p>\n<ul>\n<li>\n<p><strong>\u6bd4\u55bb\uff1a<\/strong> \u5148\u5728\u7246\u4e0a\u5857\u9d09\uff0c\u518d\u628a\u756b\u6846\u639b\u4e0a\u53bb\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u7528\u9014\uff1a<\/strong> \u756b\u7c21\u55ae\u7684\u80cc\u666f\u6216\u88dd\u98fe\u3002<\/p>\n<\/li>\n<\/ul>\n<h4>2. Modifier.drawWithContent<\/h4>\n<p>\u5b83\u628a\u7e6a\u88fd\u4e3b\u5c0e\u6b0a\u4ea4\u7d66\u4f60\uff0c\u4f60\u5fc5\u9808\u624b\u52d5\u547c\u53eb drawContent()\u3002\u4f60\u80fd\u5728\u5167\u5bb9<strong>\u524d\u5f8c<\/strong>\u90fd\u756b\u5716\u3002<\/p>\n<ul>\n<li>\n<p><strong>\u6bd4\u55bb\uff1a<\/strong> \u651d\u5f71\u5e2b\uff0c\u80fd\u6c7a\u5b9a\u5148\u52a0\u6ffe\u93e1\u518d\u62cd\u7167\uff0c\u6216\u62cd\u5b8c\u7167\u518d\u52a0\u6d6e\u6c34\u5370\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u7528\u9014\uff1a<\/strong> \u505a\u5167\u5bb9\u906e\u7f69\u3001\u6f38\u5c64\u6216\u6dfb\u52a0\u908a\u6846\u3002<\/p>\n<\/li>\n<\/ul>\n<h4>3. Modifier.drawWithCache<\/h4>\n<p>\u9019\u662f\u524d\u5169\u8005\u7684\u6548\u80fd\u9032\u5316\u7248\u3002\u53ea\u8981\u5143\u4ef6\u5c3a\u5bf8\u6216\u4f60\u6307\u5b9a\u7684\u72c0\u614b\u6c92\u8b8a\uff0c\u5b83\u5c31\u6703\u91cd\u7528\u5feb\u53d6\u597d\u7684\u9ad8\u6210\u672c\u7e6a\u5716\u7269\u4ef6\uff08\u5982 Path\u3001Shader\u3001Brush\uff09\uff0c\u7701\u53bb\u6bcf\u5e40\u91cd\u65b0\u5efa\u69cb\u9019\u4e9b\u7269\u4ef6\u7684\u958b\u92b7\u3002\u4f46\u6ce8\u610f\uff0conDrawBehind \/ onDrawWithContent \u5167\u7684\u7e6a\u5716\u6307\u4ee4\u5728\u6bcf\u500b Draw phase \u4ecd\u6703\u88ab\u5b8c\u6574\u57f7\u884c\u3002<\/p>\n<ul>\n<li>\n<p><strong>\u6bd4\u55bb\uff1a<\/strong> \u9910\u5ef3\u9810\u5148\u505a\u597d\u4e00\u9053\u529f\u592b\u83dc\uff0c\u5ba2\u4eba\u9ede\u4e86\u76f4\u63a5\u4e0a\uff0c\u4e0d\u7528\u7b49\u5eda\u5e2b\u73fe\u505a\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u7528\u9014\uff1a<\/strong> \u4efb\u4f55\u6d89\u53ca\u8907\u96dc\u8a08\u7b97\u3001\u5efa\u7acb Shader \u6216 Path \u7684\u7e6a\u5716\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u7c21\u55ae\u80cc\u666f\uff1f<\/strong> \u7528 drawBehind\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u8981\u758a\u52a0\u5167\u5bb9\uff1f<\/strong> \u7528 drawWithContent\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u7e6a\u5716\u908f\u8f2f\u7a0d\u5fae\u8907\u96dc\uff1f<\/strong> <strong>\u4e00\u5f8b\u7528 drawWithCache \u5305\u8d77\u4f86\uff01<\/strong> \u9019\u662f\u907f\u514d App \u5361\u9813\u7684\u4fdd\u547d\u7b26\u3002<\/p>\n<\/li>\n<li><\/li>\n<\/ul>\n<hr>\n<p>\u7b2c\u4e8c\u7248\uff0c\u500b\u4eba\u8a8d\u70ba\u9700\u8981\u52a0\u5165\u7a0b\u5f0f\u78bc\u7bc4\u4f8b\u624d\u7b26\u5408\u6211\u5bebblog \u7684\u521d\u8877<\/p>\n<hr>\n<p>\u6211\u5011\u7528 <code>Modifier.draw<\/code> \u51fd\u6578\u4f86\u5be6\u4f5c\u4e00\u500b\u5713\u9905\u5716\uff0c\u5feb\u901f\u4e86\u89e3\u4e09\u8005\u7684\u5340\u5225\u3002<\/p>\n<p>\u9996\u5148\uff0c\u9019\u662f\u5713\u9905\u5716\u5171\u7528\u7684\u8cc7\u6599\uff1a<\/p>\n<pre><code class=\"hljs language-kotlin\"><span class=\"hljs-keyword\">import<\/span> androidx.compose.ui.graphics.Color <span class=\"hljs-keyword\">as<\/span> ComposeColor\n\n<span class=\"hljs-comment\">\/\/ \u5713\u9905\u5716\u7684\u6578\u64da\u6a21\u578b<\/span>\n<span class=\"hljs-keyword\">data<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title class_\">PieSlice<\/span>(<span class=\"hljs-keyword\">val<\/span> value: <span class=\"hljs-built_in\">Float<\/span>, <span class=\"hljs-keyword\">val<\/span> color: ComposeColor, <span class=\"hljs-keyword\">val<\/span> label: String)\n\n<span class=\"hljs-comment\">\/\/ \u5713\u9905\u5716\u7684\u6578\u64da<\/span>\n<span class=\"hljs-keyword\">val<\/span> pieChartData = listOf(\n    PieSlice(<span class=\"hljs-number\">30f<\/span>, ComposeColor.Red, <span class=\"hljs-string\">&quot;Apple&quot;<\/span>),\n    PieSlice(<span class=\"hljs-number\">20f<\/span>, ComposeColor.Blue, <span class=\"hljs-string\">&quot;Banana&quot;<\/span>),\n    PieSlice(<span class=\"hljs-number\">15f<\/span>, ComposeColor.Green, <span class=\"hljs-string\">&quot;Orange&quot;<\/span>),\n    PieSlice(<span class=\"hljs-number\">35f<\/span>, ComposeColor.Magenta, <span class=\"hljs-string\">&quot;Grape&quot;<\/span>)\n)<\/code><\/pre>\n<hr>\n<h3>1. <code>Modifier.drawBehind<\/code>\uff1a\u80cc\u666f\u677f<\/h3>\n<p>\u5728\u5143\u4ef6\u5167\u5bb9\u4e4b\u524d\u7e6a\u88fd\uff0c\u9069\u5408\u756b\u7c21\u55ae\u7684\u80cc\u666f\u6216\u88dd\u98fe\u3002<\/p>\n<p>\u6bd4\u55bb\uff1a \u5148\u5728\u7246\u4e0a\u5857\u9d09\uff0c\u518d\u628a\u756b\u6846\u639b\u4e0a\u53bb\u3002<\/p>\n<pre><code class=\"hljs language-kotlin\"><span class=\"hljs-keyword\">import<\/span> androidx.compose.ui.draw.drawBehind\n<span class=\"hljs-keyword\">import<\/span> androidx.compose.foundation.layout.*\n<span class=\"hljs-keyword\">import<\/span> androidx.compose.material3.Text\n<span class=\"hljs-keyword\">import<\/span> androidx.compose.runtime.Composable\n<span class=\"hljs-keyword\">import<\/span> androidx.compose.ui.Modifier\n\n<span class=\"hljs-meta\">@Composable<\/span>\n<span class=\"hljs-function\"><span class=\"hljs-keyword\">fun<\/span> <span class=\"hljs-title\">SimplePieChartWithDrawBehind<\/span><span class=\"hljs-params\">(<span class=\"hljs-keyword\">data<\/span>: <span class=\"hljs-type\">List<\/span>&lt;<span class=\"hljs-type\">PieSlice<\/span>&gt;, modifier: <span class=\"hljs-type\">Modifier<\/span> = Modifier)<\/span><\/span> {\n    <span class=\"hljs-keyword\">val<\/span> total = <span class=\"hljs-keyword\">data<\/span>.sumOf { it.value.toDouble() }.toFloat()\n\n    Box(modifier = modifier.fillMaxSize().drawBehind { <span class=\"hljs-comment\">\/\/ \u5728\u5167\u5bb9\u524d\u7e6a\u88fd<\/span>\n        <span class=\"hljs-keyword\">var<\/span> startAngle = <span class=\"hljs-number\">0f<\/span>\n        <span class=\"hljs-keyword\">data<\/span>.forEach { slice -&gt;\n            <span class=\"hljs-keyword\">val<\/span> sweepAngle = (slice.value \/ total) * <span class=\"hljs-number\">360f<\/span>\n            drawArc(\n                color = slice.color,\n                startAngle = startAngle,\n                sweepAngle = sweepAngle,\n                useCenter = <span class=\"hljs-literal\">true<\/span>\n            )\n            startAngle += sweepAngle\n        }\n    }) {\n        <span class=\"hljs-comment\">\/\/ \u5167\u5bb9 (Text) \u6703\u81ea\u52d5\u758a\u5728\u5713\u9905\u5716\u4e4b\u4e0a<\/span>\n        Column {\n             <span class=\"hljs-keyword\">data<\/span>.forEach { slice -&gt; Text(text = slice.label) }\n        }\n    }\n}<\/code><\/pre>\n<p><code>drawBehind<\/code> \u5728 <code>Box<\/code> \u7684\u80cc\u666f\u4e0a\u756b\u5713\u9905\u5716\uff0c<code>Box<\/code> \u88e1\u9762\u7684 <code>Column<\/code> \u548c <code>Text<\/code> \u6703\u81ea\u7136\u5730\u5448\u73fe\u5728\u5716\u7684\u4e0a\u65b9\u3002\u8a9e\u6cd5\u6700\u7c21\u55ae\u3002<\/p>\n<hr>\n<h3>2. <code>Modifier.drawWithContent<\/code>\uff1a\u7e6a\u88fd\u4e3b\u5c0e\u6b0a<\/h3>\n<p>\u8b93\u4f60\u5b8c\u5168\u63a7\u5236\u7e6a\u5716\u9806\u5e8f\uff0c\u4f60\u5fc5\u9808\u624b\u52d5\u547c\u53eb drawContent() \u4f86\u6c7a\u5b9a\u4f55\u6642\u7e6a\u88fd\u5143\u4ef6\u5167\u5bb9\u3002<\/p>\n<p>\u6bd4\u55bb\uff1a \u50cf\u651d\u5f71\u5e2b\uff0c\u80fd\u6c7a\u5b9a\u5148\u52a0\u6ffe\u93e1\uff08\u7e6a\u88fd\uff09\uff0c\u518d\u62cd\u7167 (drawContent)\uff0c\u6216\u62cd\u5b8c\u7167\u518d\u52a0\u6d6e\u6c34\u5370\uff08\u518d\u7e6a\u88fd\uff09\u3002<\/p>\n<pre><code class=\"hljs language-kotlin\"><span class=\"hljs-keyword\">import<\/span> androidx.compose.ui.draw.drawWithContent\n\n<span class=\"hljs-meta\">@Composable<\/span>\n<span class=\"hljs-function\"><span class=\"hljs-keyword\">fun<\/span> <span class=\"hljs-title\">PieChartWithDrawWithContent<\/span><span class=\"hljs-params\">(<span class=\"hljs-keyword\">data<\/span>: <span class=\"hljs-type\">List<\/span>&lt;<span class=\"hljs-type\">PieSlice<\/span>&gt;, modifier: <span class=\"hljs-type\">Modifier<\/span> = Modifier)<\/span><\/span> {\n    <span class=\"hljs-keyword\">val<\/span> total = <span class=\"hljs-keyword\">data<\/span>.sumOf { it.value.toDouble() }.toFloat()\n\n    Box(modifier = modifier.fillMaxSize().drawWithContent { <span class=\"hljs-comment\">\/\/ \u7372\u5f97\u7e6a\u88fd\u4e3b\u5c0e\u6b0a<\/span>\n        <span class=\"hljs-comment\">\/\/ 1. \u5728\u5167\u5bb9\u524d\u7e6a\u5716<\/span>\n        <span class=\"hljs-keyword\">var<\/span> startAngle = <span class=\"hljs-number\">0f<\/span>\n        <span class=\"hljs-keyword\">data<\/span>.forEach { slice -&gt;\n            <span class=\"hljs-keyword\">val<\/span> sweepAngle = (slice.value \/ total) * <span class=\"hljs-number\">360f<\/span>\n            drawArc(\n                color = slice.color,\n                startAngle = startAngle,\n                sweepAngle = sweepAngle,\n                useCenter = <span class=\"hljs-literal\">true<\/span>\n            )\n            startAngle += sweepAngle\n        }\n\n        <span class=\"hljs-comment\">\/\/ 2. \u7e6a\u88fd Box \u539f\u672c\u7684\u5167\u5bb9 (\u5982\u679c\u6709\u7684\u8a71)<\/span>\n        <span class=\"hljs-comment\">\/\/ drawContent() <\/span>\n\n        <span class=\"hljs-comment\">\/\/ 3. \u5728\u5167\u5bb9\u5f8c\u7e6a\u5716 (\u4f8b\u5982\u52a0\u4e0a\u6a19\u7c64)<\/span>\n        <span class=\"hljs-comment\">\/\/ ... \u7e6a\u88fd\u6587\u5b57\u7684\u908f\u8f2f ...<\/span>\n    })\n}<\/code><\/pre>\n<p>\u4f60\u53ef\u4ee5\u81ea\u7531\u6c7a\u5b9a\u5728 <code>drawContent()<\/code> \u524d\u5f8c\u90fd\u52a0\u4e0a\u7e6a\u5716\u908f\u8f2f\uff0c\u9069\u5408\u505a\u906e\u7f69\u3001\u6f38\u5c64\u7b49\u9700\u8981\u758a\u52a0\u7684\u6548\u679c\u3002<\/p>\n<hr>\n<h3>3. <code>Modifier.drawWithCache<\/code>\uff1a\u6548\u80fd<\/h3>\n<p>\u9019\u662f\u6548\u80fd\u7684\u4fdd\u547d\u7b26\u3002\u7e6a\u5716\u908f\u8f2f\u53ea\u5728\u5143\u4ef6\u5c3a\u5bf8\u6216\u4f60\u6307\u5b9a\u7684\u72c0\u614b\u6539\u8b8a\u6642\u624d\u91cd\u8dd1\uff0c\u5426\u5247\u76f4\u63a5\u4f7f\u7528\u5feb\u53d6\u597d\u7684\u7d50\u679c\u3002<\/p>\n<p>\u6bd4\u55bb\uff1a \u9910\u5ef3\u9810\u5148\u505a\u597d\u4e00\u9053\u529f\u592b\u83dc\uff0c\u5ba2\u4eba\u9ede\u4e86\u76f4\u63a5\u4e0a\uff0c\u4e0d\u7528\u7b49\u5eda\u5e2b\u73fe\u505a\u3002<\/p>\n<pre><code class=\"hljs language-kotlin\"><span class=\"hljs-keyword\">import<\/span> androidx.compose.ui.draw.drawWithCache\n\n<span class=\"hljs-meta\">@Composable<\/span>\n<span class=\"hljs-function\"><span class=\"hljs-keyword\">fun<\/span> <span class=\"hljs-title\">PerformantPieChartWithDrawWithCache<\/span><span class=\"hljs-params\">(<span class=\"hljs-keyword\">data<\/span>: <span class=\"hljs-type\">List<\/span>&lt;<span class=\"hljs-type\">PieSlice<\/span>&gt;, modifier: <span class=\"hljs-type\">Modifier<\/span> = Modifier)<\/span><\/span> {\n    <span class=\"hljs-keyword\">val<\/span> total = <span class=\"hljs-keyword\">data<\/span>.sumOf { it.value.toDouble() }.toFloat()\n\n    Box(modifier = modifier.fillMaxSize().drawWithCache {\n        <span class=\"hljs-comment\">\/\/ \u8907\u96dc\u7684\u8a08\u7b97\u6216\u7269\u4ef6\u5efa\u7acb (\u5982 Path, Shader) \u653e\u9019\u88e1<\/span>\n        <span class=\"hljs-comment\">\/\/ \u9019\u88e1\u7684\u7a0b\u5f0f\u78bc\u53ea\u5728\u5c3a\u5bf8\u6539\u8b8a\u6642\u91cd\u8dd1<\/span>\n\n        onDrawWithContent { <span class=\"hljs-comment\">\/\/ \u5be6\u969b\u7684\u7e6a\u5716\u6307\u4ee4\u653e\u9019\u88e1<\/span>\n            <span class=\"hljs-keyword\">var<\/span> startAngle = <span class=\"hljs-number\">0f<\/span>\n            <span class=\"hljs-keyword\">data<\/span>.forEach { slice -&gt;\n                <span class=\"hljs-keyword\">val<\/span> sweepAngle = (slice.value \/ total) * <span class=\"hljs-number\">360f<\/span>\n                drawArc(\n                    color = slice.color,\n                    startAngle = startAngle,\n                    sweepAngle = sweepAngle,\n                    useCenter = <span class=\"hljs-literal\">true<\/span>\n                )\n                startAngle += sweepAngle\n            }\n            <span class=\"hljs-comment\">\/\/ drawContent() \/\/ \u5982\u679c\u9700\u8981\uff0c\u4e5f\u53ef\u4ee5\u547c\u53eb<\/span>\n        }\n    })\n}<\/code><\/pre>\n<p>\u5c07\u7e6a\u5716\u908f\u8f2f\u5305\u5728 <code>onDrawWithContent<\/code> \u4e2d\u3002\u53ea\u8981\u5143\u4ef6\u5c3a\u5bf8\u6216\u4f60\u6307\u5b9a\u7684\u72c0\u614b\u6c92\u8b8a\uff0c\u5b83\u5c31\u6703\u91cd\u7528\u5feb\u53d6\u597d\u7684\u9ad8\u6210\u672c\u7e6a\u5716\u7269\u4ef6\uff08\u5982 Path\u3001Shader\u3001Brush\uff09\uff0c\u7701\u53bb\u6bcf\u5e40\u91cd\u65b0\u5efa\u69cb\u9019\u4e9b\u7269\u4ef6\u7684\u958b\u92b7\u3002\u4f46\u6ce8\u610f\uff0conDrawBehind \/ onDrawWithContent \u5167\u7684\u7e6a\u5716\u6307\u4ee4\u5728\u6bcf\u500b Draw phase \u4ecd\u6703\u88ab\u5b8c\u6574\u57f7\u884c\u3002<\/p>\n<h3><\/h3>\n","protected":false},"excerpt":{"rendered":"<p>Compose \u7684\u81ea\u8a02\u7e6a\u5716\u662f\u6548\u80fd\u6bba\u624b\u3002\u6bcf\u6b21\u756b\u9762\u91cd\u7d44\uff0c\u4f60\u7684\u7e6a\u5716\u908f\u8f2f\u5c31\u5f97\u91cd\u8dd1\u4e00\u6b21\uff0cFPS \u96a8\u6642\u53ef\u80fd\u5d29\u76e4\u3002 1. M [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1258,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[86],"tags":[207,124],"_links":{"self":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/653"}],"collection":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=653"}],"version-history":[{"count":10,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/653\/revisions"}],"predecessor-version":[{"id":1545,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/653\/revisions\/1545"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/media\/1258"}],"wp:attachment":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=653"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=653"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=653"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}