相信很多接触过jQuery的小伙伴对bind()函数一点都不陌生吧,但是很多小伙伴还不是很清bind()的含义与使用,bind()
函数用于为每个匹配元素的一个或多个事件绑定事件处理函数、今天我们就带大家详细介绍下jQuery中关于bind()函数详解!
此外,你还可以额外传递给事件处理函数一些所需的数据。
执行bind()
时,事件处理函数会绑定到每个匹配元素上。因此你使用bind()
所有button元素绑定了click事件,是为当时文档中存在的每个button元素绑定click事件。如果之后你向文档中添加了新的button元素,绑定事件不会对其生效。如果你希望绑定事件对未来新添加的元素也生效,请使用on()、delegate()、live()等事件函数(尽量优先使用靠前的事件函数)。
此外,你可以为同一元素、同一事件类型绑定多个事件处理函数。触发事件时,jQuery会按照绑定的先后顺序依次执行绑定的事件处理函数。
要删除通过bind()
绑定的事件,请使用unbind()函数。
该函数属于jQuery
对象(实例)。
语法
bind()
函数主要有以下两种形式的用法:
用法一:
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jQueryObject.bind( events [, data ], handler )
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用法二:jQuery 1.4.3 新增支持该用法。
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jQueryObject.bind( events [, data ] [, isDefaultBubble ] )
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用法三:jQuery 1.4 新增支持该用法。
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jQueryObject.bind( eventsMap )
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参数
参数 |
描述 |
events |
String类型一个或多个用空格分隔的事件类型和可选的命名空间,例如"click"、"focus click"、"keydown.myPlugin"。 |
data |
可选/任意类型触发事件时,需要通过event.data传递给事件处理函数的任意数据。 |
handler |
Function类型指定的事件处理函数。 |
isDefaultBubble |
可选/Boolean类型指定触发事件时,是否允许元素的默认行为和事件冒泡。默认为true 。 |
eventsMap |
Object类型一个Object对象,其每个属性对应事件类型和可选的命名空间(参数events ),属性值对应绑定的事件处理函数(参数handler )。 |
关于参数events
中可选的命名空间(1.4.3+才支持),请参考最下面的示例代码。
参数handler
中的this
指向当前DOM元素。bind()
还会为handler
传入一个参数:表示当前事件的Event对象。
参数handler
的返回值与DOM原生事件的处理函数返回值作用一致。例如submit(表单提交)事件的事件处理函数返回false
,可以阻止表单的提交。
参数isDefaultBubble
用于指示是否允许元素的默认行为和事件冒泡。如果该值为false
,它将阻止元素的默认行为(例如:触发click事件的链接的默认跳转行为,触发submit事件的表单的默认提交行为)和事件的冒泡传递。
返回值
bind()
函数的返回值为jQuery类型,返回当前jQuery对象本身。
示例&说明
以点击事件("click")为例,以下是jQuery中事件函数的常规用法(某些函数也存在其它形式的用法,此处暂不列出):
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<span class= "com" > // 这里的选择器selector用于指定可以触发事件的元素<span class="pln"><br data-filtered="filtered">// 这里的选择器ancestor应是selector的祖辈元素,selector触发的事件可以被其祖辈元素在事件流中捕获,从而以"委托代理"的形式触发事件。<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// jQuery 1.0+ (1.4.3+支持参数data)<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"selector"<span class="pun">).<span class="pln">click<span class="pun">(<span class="pln"> <span class="pun">[<span class="pln"> data <span class="pun">,]<span class="pln"> handler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// jQuery 1.0+ (1.4.3+支持参数data)<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"selector"<span class="pun">).<span class="pln">bind<span class="pun">(<span class="pln"> <span class="str">"click"<span class="pln"> <span class="pun">[,<span class="pln"> data <span class="pun">],<span class="pln"> handler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// jQuery 1.3+ (1.4+支持参数data)<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"selector"<span class="pun">).<span class="pln">live<span class="pun">(<span class="pln"> <span class="str">"click"<span class="pln"> <span class="pun">[,<span class="pln"> data <span class="pun">],<span class="pln"> handler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// jQuery 1.4.2+<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"ancestor"<span class="pun">).<span class="pln">delegate<span class="pun">(<span class="pln"> <span class="str">"selector"<span class="pun">,<span class="pln"> <span class="str">"click"<span class="pln"> <span class="pun">[,<span class="pln"> data <span class="pun">],<span class="pln"> handler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// jQuery 1.7+<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"ancestor"<span class="pun">).<span class="pln">on<span class="pun">(<span class="pln"> <span class="str">"click"<span class="pun">,<span class="pln"> <span class="str">"selector"<span class="pln"> <span class="pun">[,<span class="pln"> data <span class="pun">],<span class="pln"> handler <span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
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请参考下面这段初始HTML代码:
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< span class = "tag" >< p <span class = "pln" > < span class = "atn" >id< span class = "pun" >=< span class = "atv" >"n1"< span class = "tag" >>< span class = "pln" >< br data-filtered = "filtered" > < span class = "tag" >< p <span class = "pln" > < span class = "atn" >id< span class = "pun" >=< span class = "atv" >"n2"< span class = "tag" >>< span >< span class = "pln" >CodePlayer< span class = "tag" ></ span ></ p >< span class = "pln" >< br data-filtered = "filtered" > < span class = "tag" >< p <span class = "pln" > < span class = "atn" >id< span class = "pun" >=< span class = "atv" >"n3"< span class = "tag" >>< span >< span class = "pln" >专注于编程开发技术分享< span class = "tag" ></ span ></ p >< span class = "pln" >< br data-filtered = "filtered" > < span class = "tag" >< em <span class = "pln" > < span class = "atn" >id< span class = "pun" >=< span class = "atv" >"n4"< span class = "tag" >>< span class = "pln" >http://www.365mini.com< span class = "tag" ></ em >< span class = "pln" >< br data-filtered = "filtered" ></ p >< span class = "pln" >< br data-filtered = "filtered" >< p <span class = "pln" > < span class = "atn" >id< span class = "pun" >=< span class = "atv" >"n5"< span class = "tag" >>< span class = "pln" >Google< span class = "tag" ></ p ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span >
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我们为<p>中的所有<p>元素绑定点击事件:
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< span class = "com" >//为p中的所有p元素的click事件绑定事件处理函数< span class = "pln" >< br data-filtered = "filtered" >//只有n2、n3可以触发该事件< span class = "pln" >< br data-filtered = "filtered" >$< span class = "pun" >(< span class = "str" >"p p"< span class = "pun" >).< span class = "pln" >bind< span class = "pun" >(< span class = "str" >"click"< span class = "pun" >,< span class = "pln" > < span class = "kwd" >function< span class = "pun" >(){< span class = "pln" >< br data-filtered = "filtered" >// 这里的this指向触发点击事件的p元素(Element)< span class = "pln" >< br data-filtered = "filtered" > alert< span class = "pun" >(< span class = "pln" > $< span class = "pun" >(< span class = "kwd" >this< span class = "pun" >).< span class = "pln" >text< span class = "pun" >()< span class = "pln" > < span class = "pun" >);< span class = "pln" >< br data-filtered = "filtered" >});</ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span ></ span >
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运行代码(以下代码请自行复制到演示页面运行)
此外,我们还可以同时绑定多个事件,并为事件处理函数传递一些附加的数据,我们可以通过jQuery为事件处理函数传入的参数event
(Event事件对象)来进行处理:
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<span class= "kwd" > var <span class= "pln" > obj <span class= "pun" >=<span class= "pln" > <span class= "pun" >{<span class= "pln" > id<span class= "pun" >:<span class= "pln" > <span class= "lit" >5<span class= "pun" >,<span class= "pln" > name<span class= "pun" >:<span class= "pln" > <span class= "str" > "王五" <span class= "pln" > <span class= "pun" >};<span class= "pln" ><br data-filtered= "filtered" ><br data-filtered= "filtered" > //为n5绑定mouseenter mouseleave两个事件,并为其传入附加数据obj<span class="pln"><br data-filtered="filtered">// 附加数据可以是任意类型<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"#n5"<span class="pun">).<span class="pln">bind<span class="pun">(<span class="str">"mouseenter mouseleave"<span class="pun">,<span class="pln"> obj<span class="pun">,<span class="pln"> <span class="kwd">function<span class="pun">(<span class="pln">event<span class="pun">){<span class="pln"><br data-filtered="filtered"> <span class="kwd">var<span class="pln"> $me <span class="pun">=<span class="pln"> $<span class="pun">(<span class="kwd">this<span class="pun">);<span class="pln"><br data-filtered="filtered"> <span class="kwd">var<span class="pln"> obj <span class="pun">=<span class="pln"> event<span class="pun">.<span class="pln">data<span class="pun">;<span class="pln"> <span class="com">// 这就是传入的附加数据<span class="pln"><br data-filtered="filtered"> <span class="kwd">if<span class="pun">(<span class="pln"> event<span class="pun">.<span class="pln">type <span class="pun">==<span class="pln"> <span class="str">"mouseenter"<span class="pun">){<span class="pln"><br data-filtered="filtered"> $me<span class="pun">.<span class="pln">html<span class="pun">(<span class="pln"> <span class="str">"你好,"<span class="pln"> <span class="pun">+<span class="pln"> obj<span class="pun">.<span class="pln">name <span class="pun">+<span class="pln"> <span class="str">"!"<span class="pun">);<span class="pln"><br data-filtered="filtered"> <span class="pun">}<span class="kwd">else<span class="pln"> <span class="kwd">if<span class="pun">(<span class="pln">event<span class="pun">.<span class="pln">type <span class="pun">==<span class="pln"> <span class="str">"mouseleave"<span class="pln"> <span class="pun">){<span class="pln"><br data-filtered="filtered"> $me<span class="pun">.<span class="pln">html<span class="pun">(<span class="pln"> <span class="str">"再见,"<span class="pln"> <span class="pun">+<span class="pln"> obj<span class="pun">.<span class="pln">name <span class="pun">+<span class="pln"> <span class="str">"!"<span class="pun">);<span class="pln"> <br data-filtered="filtered"> <span class="pun">}<span class="pln"> <br data-filtered="filtered"><span class="pun">}<span class="pln"> <span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
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此外,如果符合条件的元素是bind()
函数执行后新添加的,绑定事件不会对其生效。同样以初始HTML代码为例,我们可以编写如下jQuery代码:
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<span class= "com" > //为p中的所有p元素的click事件绑定事件处理函数<span class="pln"><br data-filtered="filtered">//只有n2、n3可以触发该事件<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"p p"<span class="pun">).<span class="pln">bind<span class="pun">(<span class="str">"click"<span class="pun">,<span class="pln"> <span class="kwd">function<span class="pun">(<span class="pln">event<span class="pun">){<span class="pln"><br data-filtered="filtered"> alert<span class="pun">(<span class="pln"> $<span class="pun">(<span class="kwd">this<span class="pun">).<span class="pln">text<span class="pun">()<span class="pln"> <span class="pun">);<span class="pln"><br data-filtered="filtered">});<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// 新添加的n6不会触发上述click事件<span class="pln"><br data-filtered="filtered">$<span class="pun">(<span class="str">"#n1"<span class="pun">).<span class="pln">append<span class="pun">(<span class="str">‘<p id="n6">上述绑定的click事件不会对该元素也生效!</p>‘<span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
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参数events
还支持为事件类型附加额外的命名空间。当为同一元素绑定多个相同类型的事件处理函数时。使用命名空间,可以在触发事件、移除事件时限定触发或移除的范围。
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<span class= "kwd" > function <span class= "pln" > clickHandler<span class= "pun" >(<span class= "pln" >event<span class= "pun" >){<span class= "pln" ><br data-filtered= "filtered" > alert<span class= "pun" >(<span class= "pln" > <span class= "str" > "触发时的命名空间:[" <span class= "pln" > <span class= "pun" >+<span class= "pln" > event<span class= "pun" >.<span class= "pln" >namespace <span class= "pun" >+<span class= "pln" > <span class= "str" > "]" <span class= "pun" >);<span class= "pln" ><br data-filtered= "filtered" >}<span class= "pln" ><br data-filtered= "filtered" ><br data-filtered= "filtered" > var <span class= "pln" > $p <span class= "pun" >=<span class= "pln" > $<span class= "pun" >(<span class= "str" > "p" <span class= "pun" >);<span class= "pln" ><br data-filtered= "filtered" ><br data-filtered= "filtered" > // A:为所有p元素绑定click事件,定义在foo和bar两个命名空间下<span class="pln"><br data-filtered="filtered">$p<span class="pun">.<span class="pln">bind<span class="pun">(<span class="pln"> <span class="str">"click.foo.bar"<span class="pun">,<span class="pln"> clickHandler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// B:为所有p元素绑定click事件,定义在test命名空间下<span class="pln"><br data-filtered="filtered">$p<span class="pun">.<span class="pln">bind<span class="pun">(<span class="pln"> <span class="str">"click.test"<span class="pun">,<span class="pln"> clickHandler <span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">var<span class="pln"> $n2 <span class="pun">=<span class="pln"> $<span class="pun">(<span class="str">"#n2"<span class="pun">);<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// 触发所有click事件<span class="pln"><br data-filtered="filtered">$n2<span class="pun">.<span class="pln">trigger<span class="pun">(<span class="str">"click"<span class="pun">);<span class="pln"> <span class="com">// 触发A和B (event.namespace = "")<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// 触发定义在foo命名空间下的click事件<span class="pln"><br data-filtered="filtered">$n2<span class="pun">.<span class="pln">trigger<span class="pun">(<span class="str">"click.foo"<span class="pun">);<span class="pln"> <span class="com">// 触发A (event.namespace = "foo")<span class="pln"><br data-filtered="filtered">// 触发定义在bar命名空间下的click事件<span class="pln"><br data-filtered="filtered">$n2<span class="pun">.<span class="pln">trigger<span class="pun">(<span class="str">"click.bar"<span class="pun">);<span class="pln"> <span class="com">// 触发A (event.namespace = "bar")<span class="pln"><br data-filtered="filtered">// 触发同时定义在foo和bar两个命名空间下的click事件<span class="pln"><br data-filtered="filtered">$n2<span class="pun">.<span class="pln">trigger<span class="pun">(<span class="str">"click.foo.bar"<span class="pun">);<span class="pln"> <span class="com">// 触发A (event.namespace = "bar.foo")<span class="pln"><br data-filtered="filtered"><br data-filtered="filtered">// 触发定义在test命名空间下的click事件<span class="pln"><br data-filtered="filtered">$n2<span class="pun">.<span class="pln">trigger<span class="pun">(<span class="str">"click.test"<span class="pun">);<span class="pln"> <span class="com">// 触发B (event.namespace = "test")</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
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bind()
函数的参数eventsMap
是一个对象,可以"属性-值"的方式指定多个"事件类型-处理函数"。对应的示例代码如下:
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var eventsMap = {
"mouseenter" : function (event){
$( this ).html( "Hello!" );
},
"mouseleave" : function (event){
$( this ).html( "Bye!" );
}
};
//为n5绑定mouseenter mouseleave两个事件
$( "#n5" ).bind( eventsMap );
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总结:
本文使用示例代码详细的为大家分析了jQuery中关于bind()函数,相信大家对此也是有了进一步的了解,希望对你的工作有所帮助!
原文地址:https://www.cnblogs.com/dfsdfgdfg/p/10490991.html
时间: 2024-10-25 02:27:57