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author | Peter Bengtsson <mail@peterbe.com> | 2020-12-08 14:40:17 -0500 |
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committer | Peter Bengtsson <mail@peterbe.com> | 2020-12-08 14:40:17 -0500 |
commit | 33058f2b292b3a581333bdfb21b8f671898c5060 (patch) | |
tree | 51c3e392513ec574331b2d3f85c394445ea803c6 /files/zh-cn/web/api/canvasrenderingcontext2d/createpattern | |
parent | 8b66d724f7caf0157093fb09cfec8fbd0c6ad50a (diff) | |
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diff --git a/files/zh-cn/web/api/canvasrenderingcontext2d/createpattern/index.html b/files/zh-cn/web/api/canvasrenderingcontext2d/createpattern/index.html new file mode 100644 index 0000000000..fd6c4d7d0e --- /dev/null +++ b/files/zh-cn/web/api/canvasrenderingcontext2d/createpattern/index.html @@ -0,0 +1,200 @@ +--- +title: CanvasRenderingContext2D.createPattern() +slug: Web/API/CanvasRenderingContext2D/createPattern +translation_of: Web/API/CanvasRenderingContext2D/createPattern +--- +<div>{{APIRef}}</div> + +<p><code><strong>CanvasRenderingContext2D</strong></code><strong><code>.createPattern() </code></strong>是 Canvas 2D API 使用指定的图像 ({{domxref("CanvasImageSource")}})创建模式的方法。 它通过repetition参数在指定的方向上重复元图像。此方法返回一个{{domxref("CanvasPattern")}}对象。</p> + +<h2 id="语法">语法</h2> + +<pre class="syntaxbox">CanvasPattern <var><em>ctx</em>.createPattern(image, repetition);</var> +</pre> + +<h3 id="参数">参数</h3> + +<dl> + <dt><code>image</code></dt> + <dd>作为重复图像源的 {{domxref("CanvasImageSource")}} 对象。可以是下列之一: + <ul> + <li>{{domxref("HTMLImageElement")}} ({{HTMLElement("img")}}),</li> + <li>{{domxref("HTMLVideoElement")}} ({{HTMLElement("video")}}),</li> + <li>{{domxref("HTMLCanvasElement")}} ({{HTMLElement("canvas")}}),</li> + <li>{{domxref("CanvasRenderingContext2D")}},</li> + <li>{{domxref("ImageBitmap")}},</li> + <li>{{domxref("ImageData")}},</li> + <li>{{domxref("Blob")}}.</li> + </ul> + </dd> + <dt><code>repetition</code></dt> + <dd>{{domxref("DOMString")}},指定如何重复图像。允许的值有: + <ul> + <li><code>"repeat"</code> (both directions),</li> + <li><code>"repeat-x"</code> (horizontal only),</li> + <li><code>"repeat-y"</code> (vertical only), </li> + <li><code>"no-repeat"</code> (neither).</li> + </ul> + 如果为空字符串 (<code>''</code>) 或 {{jsxref("null")}} (但不是 {{jsxref("undefined")}}),repetition将被当作"repeat"。</dd> +</dl> + +<h3 id="返回值">返回值</h3> + +<dl> + <dt>{{domxref("CanvasPattern")}}</dt> + <dd>描述模式的不透明对象</dd> +</dl> + +<h2 id="示例">示例</h2> + +<h3 id="使用createPattern方法">使用<code>createPattern</code>方法</h3> + +<p>这是一段简单的代码片段,使用 <span style="font-family: consolas,monaco,andale mono,monospace;">createPattern 方法创建一个指定图像和重复的</span>{{domxref("CanvasPattern")}} 对象。创建完成后,可以使用{{domxref("CanvasPattern.setTransform()")}}方法对图案进行变形。如示例所示,你可以把此模式赋值给当前的{{domxref("CanvasRenderingContext2D.fillStyle", "fillStyle")}},当你使用{{domxref("CanvasRenderingContext2D.fillRect", "fillRect()")}} 方法时,会在 canvas 上绘制出效果。</p> + +<h4 id="HTML">HTML</h4> + +<pre class="brush: html"><canvas id="canvas"></canvas> +</pre> + +<h4 id="JavaScript">JavaScript</h4> + +<pre class="brush: js; highlight:[7]">var canvas = document.getElementById("canvas"); +var ctx = canvas.getContext("2d"); + +var img = new Image(); +img.src = 'https://mdn.mozillademos.org/files/222/Canvas_createpattern.png'; +img.onload = function() { + var pattern = ctx.createPattern(img, 'repeat'); + ctx.fillStyle = pattern; + ctx.fillRect(0,0,400,400); +}; +</pre> + +<p>编辑以下代码并在线查看canvas变化:</p> + +<div class="hidden"> +<h6 id="Playable_code">Playable code</h6> + +<pre class="brush: html"><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" style="height:120px"> +var img = new Image(); +img.src = 'https://mdn.mozillademos.org/files/222/Canvas_createpattern.png'; +img.onload = function() { + var pattern = ctx.createPattern(img, 'repeat'); + ctx.fillStyle = pattern; + ctx.fillRect(0,0,400,400); +};</textarea> +</pre> + +<pre class="brush: js">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); +</pre> +</div> + +<p>{{ EmbedLiveSample('Playable_code', 700, 380) }}</p> + +<h2 id="规范描述">规范描述</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">Comment</th> + </tr> + <tr> + <td>{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-createpattern", "CanvasRenderingContext2D.createPattern")}}</td> + <td>{{Spec2('HTML WHATWG')}}</td> + <td> </td> + </tr> + <tr> + <td>{{SpecName('HTML Canvas 2D Context W3C', "#dom-context-2d-createpattern", "CanvasRenderingContext2D.createPattern")}}</td> + <td>{{Spec2('HTML5 W3C')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="浏览器兼容性">浏览器兼容性</h2> + +<p>{{ CompatibilityTable() }}</p> + +<div id="compat-desktop"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Chrome</th> + <th>Firefox (Gecko)</th> + <th>Internet Explorer</th> + <th>Opera</th> + <th>Safari</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + </tr> + </tbody> +</table> +</div> + +<div id="compat-mobile"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Android</th> + <th>Chrome for Android</th> + <th>Firefox Mobile (Gecko)</th> + <th>IE Mobile</th> + <th>Opera Mobile</th> + <th>Safari Mobile</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + <td>{{ CompatVersionUnknown() }}</td> + </tr> + </tbody> +</table> +</div> + +<h2 id="参见">参见</h2> + +<ul> + <li>接口定义, {{domxref("CanvasRenderingContext2D")}}</li> + <li>{{domxref("CanvasPattern")}}</li> +</ul> |