From 0ccebc7eb352eda4d26d0b876fea36f24f482eec Mon Sep 17 00:00:00 2001 From: MDN Date: Sat, 17 Apr 2021 00:11:36 +0000 Subject: [CRON] sync translated content --- files/zh-cn/_redirects.txt | 3 + files/zh-cn/_wikihistory.json | 70 +++++----- .../orphaned/web/api/parentnode/append/index.html | 147 +++++++++++++++++++++ .../orphaned/web/api/parentnode/prepend/index.html | 135 +++++++++++++++++++ .../creating_and_triggering_events/index.html | 137 +++++++++++++++++++ files/zh-cn/web/api/parentnode/append/index.html | 146 -------------------- files/zh-cn/web/api/parentnode/prepend/index.html | 134 ------------------- .../creating_and_triggering_events/index.html | 136 ------------------- 8 files changed, 457 insertions(+), 451 deletions(-) create mode 100644 files/zh-cn/orphaned/web/api/parentnode/append/index.html create mode 100644 files/zh-cn/orphaned/web/api/parentnode/prepend/index.html create mode 100644 files/zh-cn/orphaned/web/guide/events/creating_and_triggering_events/index.html delete mode 100644 files/zh-cn/web/api/parentnode/append/index.html delete mode 100644 files/zh-cn/web/api/parentnode/prepend/index.html delete mode 100644 files/zh-cn/web/guide/events/creating_and_triggering_events/index.html (limited to 'files/zh-cn') diff --git a/files/zh-cn/_redirects.txt b/files/zh-cn/_redirects.txt index 5b42e7ce28..76db9cbba2 100644 --- a/files/zh-cn/_redirects.txt +++ b/files/zh-cn/_redirects.txt @@ -1728,10 +1728,12 @@ /zh-CN/docs/Web/API/ParentNode.children /zh-CN/docs/orphaned/Web/API/ParentNode/children /zh-CN/docs/Web/API/ParentNode.firstElementChild /zh-CN/docs/orphaned/Web/API/ParentNode/firstElementChild /zh-CN/docs/Web/API/ParentNode.lastElementChild /zh-CN/docs/orphaned/Web/API/ParentNode/lastElementChild +/zh-CN/docs/Web/API/ParentNode/append /zh-CN/docs/orphaned/Web/API/ParentNode/append /zh-CN/docs/Web/API/ParentNode/childElementCount /zh-CN/docs/Web/API/Element/childElementCount /zh-CN/docs/Web/API/ParentNode/children /zh-CN/docs/orphaned/Web/API/ParentNode/children /zh-CN/docs/Web/API/ParentNode/firstElementChild /zh-CN/docs/orphaned/Web/API/ParentNode/firstElementChild /zh-CN/docs/Web/API/ParentNode/lastElementChild /zh-CN/docs/orphaned/Web/API/ParentNode/lastElementChild +/zh-CN/docs/Web/API/ParentNode/prepend /zh-CN/docs/orphaned/Web/API/ParentNode/prepend /zh-CN/docs/Web/API/Performance.now() /zh-CN/docs/Web/API/Performance/now /zh-CN/docs/Web/API/Performance/内存 /zh-CN/docs/Web/API/Performance/memory /zh-CN/docs/Web/API/Position /zh-CN/docs/Web/API/GeolocationPosition @@ -2262,6 +2264,7 @@ /zh-CN/docs/Web/Guide/CSS/媒体查询 /zh-CN/docs/Web/CSS/Media_Queries/Using_media_queries /zh-CN/docs/Web/Guide/DOM /zh-CN/docs/conflicting/Web/API/Document_Object_Model_dd00a71ceceac547ab464128db6bd8ef /zh-CN/docs/Web/Guide/DOM/Whitespace_in_the_DOM /zh-CN/docs/Web/API/Document_Object_Model/Whitespace +/zh-CN/docs/Web/Guide/Events/Creating_and_triggering_events /zh-CN/docs/orphaned/Web/Guide/Events/Creating_and_triggering_events /zh-CN/docs/Web/Guide/Events/Media_events /zh-CN/docs/orphaned/Web/Guide/Events/Media_events /zh-CN/docs/Web/Guide/Events/Mutation_events /zh-CN/docs/orphaned/Web/Guide/Events/Mutation_events /zh-CN/docs/Web/Guide/Events/Touch_events /zh-CN/docs/Web/API/Touch_events diff --git a/files/zh-cn/_wikihistory.json b/files/zh-cn/_wikihistory.json index 917102ab9b..778081b0d1 100644 --- a/files/zh-cn/_wikihistory.json +++ b/files/zh-cn/_wikihistory.json @@ -16785,23 +16785,6 @@ "AlexChao" ] }, - "Web/API/ParentNode/append": { - "modified": "2020-10-15T21:51:11.120Z", - "contributors": [ - "Ende93", - "zhangchen", - "xgqfrms-GitHub", - "ziyunfei" - ] - }, - "Web/API/ParentNode/prepend": { - "modified": "2020-10-15T21:52:00.307Z", - "contributors": [ - "Ende93", - "zhuangyin", - "maicss" - ] - }, "Web/API/ParentNode/querySelector": { "modified": "2020-10-15T22:11:37.961Z", "contributors": [ @@ -28803,24 +28786,6 @@ "Jeremie" ] }, - "Web/Guide/Events/Creating_and_triggering_events": { - "modified": "2020-05-27T10:29:01.846Z", - "contributors": [ - "Carllllo", - "xingleizhao", - "but0n", - "zhangchen", - "LuSitong", - "Iamxiaozhu", - "ucev", - "xgqfrms-GitHub", - "ZhengYinBo", - "carllx", - "timwangdev", - "FredWe", - "ReyCG_sub" - ] - }, "Web/Guide/Events/Event_handlers": { "modified": "2019-03-23T23:20:11.825Z", "contributors": [ @@ -50798,5 +50763,40 @@ "khalid32", "ziyunfei" ] + }, + "orphaned/Web/API/ParentNode/append": { + "modified": "2020-10-15T21:51:11.120Z", + "contributors": [ + "Ende93", + "zhangchen", + "xgqfrms-GitHub", + "ziyunfei" + ] + }, + "orphaned/Web/API/ParentNode/prepend": { + "modified": "2020-10-15T21:52:00.307Z", + "contributors": [ + "Ende93", + "zhuangyin", + "maicss" + ] + }, + "orphaned/Web/Guide/Events/Creating_and_triggering_events": { + "modified": "2020-05-27T10:29:01.846Z", + "contributors": [ + "Carllllo", + "xingleizhao", + "but0n", + "zhangchen", + "LuSitong", + "Iamxiaozhu", + "ucev", + "xgqfrms-GitHub", + "ZhengYinBo", + "carllx", + "timwangdev", + "FredWe", + "ReyCG_sub" + ] } } \ No newline at end of file diff --git a/files/zh-cn/orphaned/web/api/parentnode/append/index.html b/files/zh-cn/orphaned/web/api/parentnode/append/index.html new file mode 100644 index 0000000000..6f06f7a420 --- /dev/null +++ b/files/zh-cn/orphaned/web/api/parentnode/append/index.html @@ -0,0 +1,147 @@ +--- +title: ParentNode.append() +slug: orphaned/Web/API/ParentNode/append +tags: + - API + - DOM + - Node + - ParentNode + - Reference +translation_of: Web/API/ParentNode/append +original_slug: Web/API/ParentNode/append +--- +
{{APIRef("DOM")}}
+ +
 ParentNode.append 方法在 ParentNode的最后一个子节点之后插入一组 {{domxref("Node")}} 对象或 {{domxref("DOMString")}} 对象。
+ +
被插入的 {{domxref("DOMString")}} 对象等价为 {{domxref("Text")}} 节点。
+ +
+ +
与 {{domxref("Node.appendChild()")}} 的差异:
+ +
+ + + +

语法

+ +
[Throws, Unscopable]
+void ParentNode.append((Node or DOMString)... nodes);
+
+ +

参数

+ +
+
nodes
+
一组要插入的 {{domxref("Node")}} 或 {{domxref("DOMString")}} 对象。
+
+ +

异常

+ + + +

示例

+ +

插入一个元素节点

+ +
var parent = document.createElement("div");
+var p = document.createElement("p");
+parent.append(p);
+
+console.log(parent.childNodes); // NodeList [ <p> ]
+
+ +

插入文本

+ +
var parent = document.createElement("div");
+parent.append("Some text");
+
+console.log(parent.textContent); // "Some text"
+ +

插入一个节点,同时插入一些文本

+ +
var parent = document.createElement("div");
+var p = document.createElement("p");
+parent.append("Some text", p);
+
+console.log(parent.childNodes); // NodeList [ #text "Some text", <p> ]
+ +

ParentNode.append() 方法在 with 语句中不生效

+ +

为了保证向后兼容,append 方法在 with 语句中会被特殊处理,详情请看 {{jsxref("Symbol.unscopables")}}。

+ +
var parent = document.createElement("div");
+
+with(parent) {
+  append("foo");
+}
+// ReferenceError: append is not defined 
+ +

Polyfill

+ +

下面的 Polyfill 只支持到 IE 9  及以上:

+ +
// Source: https://github.com/jserz/js_piece/blob/master/DOM/ParentNode/append()/append().md
+(function (arr) {
+  arr.forEach(function (item) {
+    if (item.hasOwnProperty('append')) {
+      return;
+    }
+    Object.defineProperty(item, 'append', {
+      configurable: true,
+      enumerable: true,
+      writable: true,
+      value: function append() {
+        var argArr = Array.prototype.slice.call(arguments),
+          docFrag = document.createDocumentFragment();
+
+        argArr.forEach(function (argItem) {
+          var isNode = argItem instanceof Node;
+          docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
+        });
+
+        this.appendChild(docFrag);
+      }
+    });
+  });
+})([Element.prototype, Document.prototype, DocumentFragment.prototype]);
+ +

规范

+ + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('DOM WHATWG', '#dom-parentnode-append', 'ParentNode.append()')}}{{Spec2('DOM WHATWG')}}Initial definition.
+ +

浏览器兼容

+ + + +

{{Compat("api.ParentNode.append")}}

+ +

相关链接

+ + diff --git a/files/zh-cn/orphaned/web/api/parentnode/prepend/index.html b/files/zh-cn/orphaned/web/api/parentnode/prepend/index.html new file mode 100644 index 0000000000..c2779973b0 --- /dev/null +++ b/files/zh-cn/orphaned/web/api/parentnode/prepend/index.html @@ -0,0 +1,135 @@ +--- +title: ParentNode.prepend() +slug: orphaned/Web/API/ParentNode/prepend +tags: + - API + - DOM + - Method + - Node + - ParentNode + - Reference + - prepend + - 方法 +translation_of: Web/API/ParentNode/prepend +original_slug: Web/API/ParentNode/prepend +--- +
{{APIRef("DOM")}}
+ +

ParentNode.prepend 方法可以在父节点的第一个子节点之前插入一系列{{domxref("Node")}}对象或者{{domxref("DOMString")}}对象。{{domxref("DOMString")}}会被当作{{domxref("Text")}}节点对待(也就是说插入的不是HTML代码)。

+ +

语法

+ +
ParentNode.prepend((Node or DOMString)... nodes);
+
+ +

参数

+ +
+
nodes
+
要插入的一系列{{domxref("Node")}}或者{{domxref("DOMString")}}。
+
+ +

返回值

+ +

undefined.

+ +

错误

+ + + +

例子

+ +

Prepending an element

+ +
var parent = document.createElement("div");
+var p = document.createElement("p");
+var span = document.createElement("span");
+parent.append(p);
+parent.prepend(span);
+
+console.log(parent.childNodes); // NodeList [ <span>, <p> ]
+
+ +

Prepending text

+ +
var parent = document.createElement("div");
+parent.append("Some text");
+parent.prepend("Headline: ");
+
+console.log(parent.textContent); // "Headline: Some text"
+ +

Appending an element and text

+ +
var parent = document.createElement("div");
+var p = document.createElement("p");
+parent.prepend("Some text", p);
+
+console.log(parent.childNodes); // NodeList [ #text "Some text", <p> ]
+ +

ParentNode.prepend() is unscopable

+ +

prepend()不能在with语句内使用,详情参考{{jsxref("Symbol.unscopables")}}。

+ +
var parent = document.createElement("div");
+
+with(parent) {
+  prepend("foo");
+}
+// ReferenceError: prepend is not defined 
+ +

Polyfill

+ +

使用下面的代码在IE9或更高版本中模拟prepend()方法:

+ +
// from: https://github.com/jserz/js_piece/blob/master/DOM/ParentNode/prepend()/prepend().md
+(function (arr) {
+    arr.forEach(function (item) {
+        item.prepend = item.prepend || function () {
+            var argArr = Array.prototype.slice.call(arguments),
+                docFrag = document.createDocumentFragment();
+
+            argArr.forEach(function (argItem) {
+                var isNode = argItem instanceof Node;
+                docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
+            });
+
+            this.insertBefore(docFrag, this.firstChild);
+        };
+    });
+})([Element.prototype, Document.prototype, DocumentFragment.prototype]);
+ +

说明

+ + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('DOM WHATWG', '#dom-parentnode-prepend', 'ParentNode.prepend()')}}{{Spec2('DOM WHATWG')}}Initial definition.
+ +

兼容性

+ + + +

{{Compat("api.ParentNode.prepend")}}

+ +

See also

+ + diff --git a/files/zh-cn/orphaned/web/guide/events/creating_and_triggering_events/index.html b/files/zh-cn/orphaned/web/guide/events/creating_and_triggering_events/index.html new file mode 100644 index 0000000000..dbc0f65c1f --- /dev/null +++ b/files/zh-cn/orphaned/web/guide/events/creating_and_triggering_events/index.html @@ -0,0 +1,137 @@ +--- +title: 创建和触发 events +slug: orphaned/Web/Guide/Events/Creating_and_triggering_events +tags: + - Advanced + - DOM + - Guide + - events +translation_of: Web/Guide/Events/Creating_and_triggering_events +original_slug: Web/Guide/Events/Creating_and_triggering_events +--- +

本文演示了如何创建和分派DOM事件。这些事件通常称为合成事件,而不是浏览器本身触发的事件。

+ +

创建自定义事件

+ +

Events 可以使用 Event 构造函数创建如下:

+ +
var event = new Event('build');
+
+// Listen for the event.
+elem.addEventListener('build', function (e) { ... }, false);
+
+// Dispatch the event.
+elem.dispatchEvent(event);
+ +

上述代码使用了 EventTarget.dispatchEvent() 方法。

+ +

绝大多数现代浏览器中都会支持这个构造函数(Internet Explorer 例外)。 要了解更为复杂的方法,可参考下面的 过时的方式  一节。

+ +

添加自定义数据 – CustomEvent()

+ +

要向事件对象添加更多数据,可以使用 CustomEvent 接口,detail 属性可用于传递自定义数据。
+ 例如,event 可以创建如下:

+ +
var event = new CustomEvent('build', { 'detail': elem.dataset.time });
+ +

下面的代码允许你在事件监听器中访问更多的数据:

+ +
function eventHandler(e) {
+  log('The time is: ' + e.detail);
+}
+
+ +

过时的方式

+ +

早期的创建事件的方法使用了受Java启发的API。下面展示了一个示例:

+ +
// Create the event.
+var event = document.createEvent('Event');
+
+// Define that the event name is 'build'.
+event.initEvent('build', true, true);
+
+// Listen for the event.
+document.addEventListener('build', function (e) {
+  // e.target matches document from above
+}, false);
+
+// target can be any Element or other EventTarget.
+document.dispatchEvent(event);
+
+ +

事件冒泡

+ +

通常需要从子元素触发事件,并让祖先捕获它:

+ +
<form>
+  <textarea></textarea>
+</form>
+ +
const form = document.querySelector('form');
+const textarea = document.querySelector('textarea');
+
+// Create a new event, allow bubbling, and provide any data you want to pass to the "details" property
+const eventAwesome = new CustomEvent('awesome', {
+  bubbles: true,
+  detail: { text: () => textarea.value }
+});
+
+// The form element listens for the custom "awesome" event and then consoles the output of the passed text() method
+form.addEventListener('awesome', e => console.log(e.detail.text()));
+
+// As the user types, the textarea inside the form dispatches/triggers the event to fire, and uses itself as the starting point
+textarea.addEventListener('input', e => e.target.dispatchEvent(eventAwesome));
+ +

动态创建和派发事件

+ +

元素可以侦听尚未创建的事件:

+ +
<form>
+  <textarea></textarea>
+</form>
+ +
const form = document.querySelector('form');
+const textarea = document.querySelector('textarea');
+
+form.addEventListener('awesome', e => console.log(e.detail.text()));
+
+textarea.addEventListener('input', function() {
+  // Create and dispatch/trigger an event on the fly
+  // Note: Optionally, we've also leveraged the "function expression" (instead of the "arrow function expression") so "this" will represent the element
+  this.dispatchEvent(new CustomEvent('awesome', { bubbles: true, detail: { text: () => textarea.value } }))
+});
+ + + +

触发内置事件

+ +

下面的例子演示了一个在复选框上点击(click)的模拟(就是说在程序里生成一个click事件),这个模拟点击使用了DOM方法。参见这个动态示例

+ +
function simulateClick() {
+  var event = new MouseEvent('click', {
+    'view': window,
+    'bubbles': true,
+    'cancelable': true
+  });
+  var cb = document.getElementById('checkbox');
+  var cancelled = !cb.dispatchEvent(event);
+  if (cancelled) {
+    // A handler called preventDefault.
+    alert("cancelled");
+  } else {
+    // None of the handlers called preventDefault.
+    alert("not cancelled");
+  }
+}
+
+ +

参见

+ + diff --git a/files/zh-cn/web/api/parentnode/append/index.html b/files/zh-cn/web/api/parentnode/append/index.html deleted file mode 100644 index 247291f59e..0000000000 --- a/files/zh-cn/web/api/parentnode/append/index.html +++ /dev/null @@ -1,146 +0,0 @@ ---- -title: ParentNode.append() -slug: Web/API/ParentNode/append -tags: - - API - - DOM - - Node - - ParentNode - - Reference -translation_of: Web/API/ParentNode/append ---- -
{{APIRef("DOM")}}
- -
 ParentNode.append 方法在 ParentNode的最后一个子节点之后插入一组 {{domxref("Node")}} 对象或 {{domxref("DOMString")}} 对象。
- -
被插入的 {{domxref("DOMString")}} 对象等价为 {{domxref("Text")}} 节点。
- -
- -
与 {{domxref("Node.appendChild()")}} 的差异:
- -
- - - -

语法

- -
[Throws, Unscopable]
-void ParentNode.append((Node or DOMString)... nodes);
-
- -

参数

- -
-
nodes
-
一组要插入的 {{domxref("Node")}} 或 {{domxref("DOMString")}} 对象。
-
- -

异常

- - - -

示例

- -

插入一个元素节点

- -
var parent = document.createElement("div");
-var p = document.createElement("p");
-parent.append(p);
-
-console.log(parent.childNodes); // NodeList [ <p> ]
-
- -

插入文本

- -
var parent = document.createElement("div");
-parent.append("Some text");
-
-console.log(parent.textContent); // "Some text"
- -

插入一个节点,同时插入一些文本

- -
var parent = document.createElement("div");
-var p = document.createElement("p");
-parent.append("Some text", p);
-
-console.log(parent.childNodes); // NodeList [ #text "Some text", <p> ]
- -

ParentNode.append() 方法在 with 语句中不生效

- -

为了保证向后兼容,append 方法在 with 语句中会被特殊处理,详情请看 {{jsxref("Symbol.unscopables")}}。

- -
var parent = document.createElement("div");
-
-with(parent) {
-  append("foo");
-}
-// ReferenceError: append is not defined 
- -

Polyfill

- -

下面的 Polyfill 只支持到 IE 9  及以上:

- -
// Source: https://github.com/jserz/js_piece/blob/master/DOM/ParentNode/append()/append().md
-(function (arr) {
-  arr.forEach(function (item) {
-    if (item.hasOwnProperty('append')) {
-      return;
-    }
-    Object.defineProperty(item, 'append', {
-      configurable: true,
-      enumerable: true,
-      writable: true,
-      value: function append() {
-        var argArr = Array.prototype.slice.call(arguments),
-          docFrag = document.createDocumentFragment();
-
-        argArr.forEach(function (argItem) {
-          var isNode = argItem instanceof Node;
-          docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
-        });
-
-        this.appendChild(docFrag);
-      }
-    });
-  });
-})([Element.prototype, Document.prototype, DocumentFragment.prototype]);
- -

规范

- - - - - - - - - - - - - - -
SpecificationStatusComment
{{SpecName('DOM WHATWG', '#dom-parentnode-append', 'ParentNode.append()')}}{{Spec2('DOM WHATWG')}}Initial definition.
- -

浏览器兼容

- - - -

{{Compat("api.ParentNode.append")}}

- -

相关链接

- - diff --git a/files/zh-cn/web/api/parentnode/prepend/index.html b/files/zh-cn/web/api/parentnode/prepend/index.html deleted file mode 100644 index f5e1a9fb55..0000000000 --- a/files/zh-cn/web/api/parentnode/prepend/index.html +++ /dev/null @@ -1,134 +0,0 @@ ---- -title: ParentNode.prepend() -slug: Web/API/ParentNode/prepend -tags: - - API - - DOM - - Method - - Node - - ParentNode - - Reference - - prepend - - 方法 -translation_of: Web/API/ParentNode/prepend ---- -
{{APIRef("DOM")}}
- -

ParentNode.prepend 方法可以在父节点的第一个子节点之前插入一系列{{domxref("Node")}}对象或者{{domxref("DOMString")}}对象。{{domxref("DOMString")}}会被当作{{domxref("Text")}}节点对待(也就是说插入的不是HTML代码)。

- -

语法

- -
ParentNode.prepend((Node or DOMString)... nodes);
-
- -

参数

- -
-
nodes
-
要插入的一系列{{domxref("Node")}}或者{{domxref("DOMString")}}。
-
- -

返回值

- -

undefined.

- -

错误

- - - -

例子

- -

Prepending an element

- -
var parent = document.createElement("div");
-var p = document.createElement("p");
-var span = document.createElement("span");
-parent.append(p);
-parent.prepend(span);
-
-console.log(parent.childNodes); // NodeList [ <span>, <p> ]
-
- -

Prepending text

- -
var parent = document.createElement("div");
-parent.append("Some text");
-parent.prepend("Headline: ");
-
-console.log(parent.textContent); // "Headline: Some text"
- -

Appending an element and text

- -
var parent = document.createElement("div");
-var p = document.createElement("p");
-parent.prepend("Some text", p);
-
-console.log(parent.childNodes); // NodeList [ #text "Some text", <p> ]
- -

ParentNode.prepend() is unscopable

- -

prepend()不能在with语句内使用,详情参考{{jsxref("Symbol.unscopables")}}。

- -
var parent = document.createElement("div");
-
-with(parent) {
-  prepend("foo");
-}
-// ReferenceError: prepend is not defined 
- -

Polyfill

- -

使用下面的代码在IE9或更高版本中模拟prepend()方法:

- -
// from: https://github.com/jserz/js_piece/blob/master/DOM/ParentNode/prepend()/prepend().md
-(function (arr) {
-    arr.forEach(function (item) {
-        item.prepend = item.prepend || function () {
-            var argArr = Array.prototype.slice.call(arguments),
-                docFrag = document.createDocumentFragment();
-
-            argArr.forEach(function (argItem) {
-                var isNode = argItem instanceof Node;
-                docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
-            });
-
-            this.insertBefore(docFrag, this.firstChild);
-        };
-    });
-})([Element.prototype, Document.prototype, DocumentFragment.prototype]);
- -

说明

- - - - - - - - - - - - - - -
SpecificationStatusComment
{{SpecName('DOM WHATWG', '#dom-parentnode-prepend', 'ParentNode.prepend()')}}{{Spec2('DOM WHATWG')}}Initial definition.
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兼容性

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{{Compat("api.ParentNode.prepend")}}

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See also

- - diff --git a/files/zh-cn/web/guide/events/creating_and_triggering_events/index.html b/files/zh-cn/web/guide/events/creating_and_triggering_events/index.html deleted file mode 100644 index 65249da219..0000000000 --- a/files/zh-cn/web/guide/events/creating_and_triggering_events/index.html +++ /dev/null @@ -1,136 +0,0 @@ ---- -title: 创建和触发 events -slug: Web/Guide/Events/Creating_and_triggering_events -tags: - - Advanced - - DOM - - Guide - - events -translation_of: Web/Guide/Events/Creating_and_triggering_events ---- -

本文演示了如何创建和分派DOM事件。这些事件通常称为合成事件,而不是浏览器本身触发的事件。

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创建自定义事件

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Events 可以使用 Event 构造函数创建如下:

- -
var event = new Event('build');
-
-// Listen for the event.
-elem.addEventListener('build', function (e) { ... }, false);
-
-// Dispatch the event.
-elem.dispatchEvent(event);
- -

上述代码使用了 EventTarget.dispatchEvent() 方法。

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绝大多数现代浏览器中都会支持这个构造函数(Internet Explorer 例外)。 要了解更为复杂的方法,可参考下面的 过时的方式  一节。

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添加自定义数据 – CustomEvent()

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要向事件对象添加更多数据,可以使用 CustomEvent 接口,detail 属性可用于传递自定义数据。
- 例如,event 可以创建如下:

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var event = new CustomEvent('build', { 'detail': elem.dataset.time });
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下面的代码允许你在事件监听器中访问更多的数据:

- -
function eventHandler(e) {
-  log('The time is: ' + e.detail);
-}
-
- -

过时的方式

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早期的创建事件的方法使用了受Java启发的API。下面展示了一个示例:

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// Create the event.
-var event = document.createEvent('Event');
-
-// Define that the event name is 'build'.
-event.initEvent('build', true, true);
-
-// Listen for the event.
-document.addEventListener('build', function (e) {
-  // e.target matches document from above
-}, false);
-
-// target can be any Element or other EventTarget.
-document.dispatchEvent(event);
-
- -

事件冒泡

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通常需要从子元素触发事件,并让祖先捕获它:

- -
<form>
-  <textarea></textarea>
-</form>
- -
const form = document.querySelector('form');
-const textarea = document.querySelector('textarea');
-
-// Create a new event, allow bubbling, and provide any data you want to pass to the "details" property
-const eventAwesome = new CustomEvent('awesome', {
-  bubbles: true,
-  detail: { text: () => textarea.value }
-});
-
-// The form element listens for the custom "awesome" event and then consoles the output of the passed text() method
-form.addEventListener('awesome', e => console.log(e.detail.text()));
-
-// As the user types, the textarea inside the form dispatches/triggers the event to fire, and uses itself as the starting point
-textarea.addEventListener('input', e => e.target.dispatchEvent(eventAwesome));
- -

动态创建和派发事件

- -

元素可以侦听尚未创建的事件:

- -
<form>
-  <textarea></textarea>
-</form>
- -
const form = document.querySelector('form');
-const textarea = document.querySelector('textarea');
-
-form.addEventListener('awesome', e => console.log(e.detail.text()));
-
-textarea.addEventListener('input', function() {
-  // Create and dispatch/trigger an event on the fly
-  // Note: Optionally, we've also leveraged the "function expression" (instead of the "arrow function expression") so "this" will represent the element
-  this.dispatchEvent(new CustomEvent('awesome', { bubbles: true, detail: { text: () => textarea.value } }))
-});
- - - -

触发内置事件

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下面的例子演示了一个在复选框上点击(click)的模拟(就是说在程序里生成一个click事件),这个模拟点击使用了DOM方法。参见这个动态示例

- -
function simulateClick() {
-  var event = new MouseEvent('click', {
-    'view': window,
-    'bubbles': true,
-    'cancelable': true
-  });
-  var cb = document.getElementById('checkbox');
-  var cancelled = !cb.dispatchEvent(event);
-  if (cancelled) {
-    // A handler called preventDefault.
-    alert("cancelled");
-  } else {
-    // None of the handlers called preventDefault.
-    alert("not cancelled");
-  }
-}
-
- -

参见

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