From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- .../ispointinstroke/index.html | 193 +++++++++++++++++++++ 1 file changed, 193 insertions(+) create mode 100644 files/zh-cn/web/api/canvasrenderingcontext2d/ispointinstroke/index.html (limited to 'files/zh-cn/web/api/canvasrenderingcontext2d/ispointinstroke') diff --git a/files/zh-cn/web/api/canvasrenderingcontext2d/ispointinstroke/index.html b/files/zh-cn/web/api/canvasrenderingcontext2d/ispointinstroke/index.html new file mode 100644 index 0000000000..8732970d18 --- /dev/null +++ b/files/zh-cn/web/api/canvasrenderingcontext2d/ispointinstroke/index.html @@ -0,0 +1,193 @@ +--- +title: CanvasRenderingContext2D.isPointInStroke() +slug: Web/API/CanvasRenderingContext2D/isPointInStroke +tags: + - isPointInStroke + - 方法 + - 检测 +translation_of: Web/API/CanvasRenderingContext2D/isPointInStroke +--- +
{{APIRef}}
+ +

CanvasRenderingContext2D.isPointInStroke()是 Canvas 2D API 用于检测某点是否在路径的描边线上的方法。

+ +

语法

+ +
boolean ctx.isPointInStroke(x, y);
+boolean ctx.isPointInStroke(path, x, y);
+
+ +

参数

+ +
+
x
+
检测点的X坐标。
+
y
+
检测点的Y坐标。
+
path
+
{{domxref("Path2D")}} 路径。
+
+ +

返回值

+ +
+
{{jsxref("Boolean")}}
+
一个布尔值，当这个点在路径的描边线上，则返回true，否则返回false。
+
+ +

示例

+ +

使用isPointInStroke方法

+ +

这只是一个使用 isPointInStroke 方法的简单的代码片段，用于检测一个点是否在路径的描边线上。

+ +

HTML

+ +
<canvas id="canvas"></canvas>
+
+ +

JavaScript

+ +
var canvas = document.getElementById("canvas");
+var ctx = canvas.getContext("2d");
+
+ctx.rect(10, 10, 100, 100);
+ctx.stroke();
+console.log(ctx.isPointInStroke(10, 10)); // true
+
+ +

修改线面的代码，在线查看 canvas 的变化，并在你的控制台查看日至信息：

+ +
+
Playable code
+ +
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
+<div class="playable-buttons">
+  <input id="edit" type="button" value="Edit" />
+  <input id="reset" type="button" value="Reset" />
+</div>
+<textarea id="code" class="playable-code">
+ctx.rect(10, 10, 100, 100);
+ctx.stroke();
+console.log(ctx.isPointInStroke(10, 10)); // true</textarea>
+
+ +
var canvas = document.getElementById("canvas");
+var ctx = canvas.getContext("2d");
+var textarea = document.getElementById("code");
+var reset = document.getElementById("reset");
+var edit = document.getElementById("edit");
+var code = textarea.value;
+
+function drawCanvas() {
+  ctx.clearRect(0, 0, canvas.width, canvas.height);
+  eval(textarea.value);
+}
+
+reset.addEventListener("click", function() {
+  textarea.value = code;
+  drawCanvas();
+});
+
+edit.addEventListener("click", function() {
+  textarea.focus();
+})
+
+textarea.addEventListener("input", drawCanvas);
+window.addEventListener("load", drawCanvas);
+
+
+ +

{{ EmbedLiveSample('Playable_code', 700, 360) }}

+ +

规范描述

+ + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-ispointinstroke", "CanvasRenderingContext2D.isPointInStroke")}}{{Spec2('HTML WHATWG')}} 
+ +

浏览器兼容性

+ +

{{ CompatibilityTable() }}

+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}
Path parameter{{ CompatVersionUnknown() }}{{ CompatGeckoDesktop(31) }}{{ CompatNo }}{{ CompatVersionUnknown() }}{{ CompatNo }}
+
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}{{ CompatVersionUnknown() }}
Path parameter{{ CompatUnknown() }}{{ CompatUnknown() }}{{ CompatGeckoMobile(31) }}{{ CompatUnknown() }}{{ CompatUnknown() }}{{ CompatUnknown() }}
+
+ +

参见

+ + -- cgit v1.2.3-54-g00ecf