无涯教程-jQuery - ajaxStart( callback )方法函数 ajaxStart(callback)

ajaxStart(callback)方法附有一个函数，只要AJAX请求开始且尚无活动，该函数便会执行。这是一个Ajax事件。

ajaxStart( callback ) - 语法

$(document).ajaxStart( callback )

这是此方法使用的所有参数的描述-

callback - 要执行的功能。

ajaxStart( callback ) - 示例

假设无涯教程在result.html文件中包含以下HTML内容-

<h1>THIS IS RESULT...</h1>

以下是一个简单的示例，简单说明了此方法的用法。

<html>
   <head>
      <title>The jQuery Example</title>
      <script type="text/javascript" 
         src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js">
      </script>
  </span><span class="tag">&lt;script</span><span class="pln"> </span><span class="atn">type</span><span class="pun">=</span><span class="atv">"text/javascript"</span><span class="pln"> </span><span class="atn">language</span><span class="pun">=</span><span class="atv">"javascript"</span><span class="tag">&gt;</span><span class="pln">
     $</span><span class="pun">(</span><span class="pln">document</span><span class="pun">).</span><span class="pln">ready</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
        </span><span class="com">/* Global variable */</span><span class="pln">
        </span><span class="kwd">var</span><span class="pln"> count</span><span class="pun">=</span><span class="lit">0</span><span class="pun">;</span><span class="pln">

        $</span><span class="pun">(</span><span class="str">"#driver"</span><span class="pun">).</span><span class="pln">click</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(</span><span class="pln">event</span><span class="pun">){</span><span class="pln">
           $</span><span class="pun">(</span><span class="str">#stage1</span><span class="pun">).</span><span class="pln">load</span><span class="pun">(</span><span class="str">result.html</span><span class="pun">);</span><span class="pln">
        </span><span class="pun">});</span><span class="pln">
			
        </span><span class="com">/* Gets called when request starts */</span><span class="pln">
			
        $</span><span class="pun">(</span><span class="pln">document</span><span class="pun">).</span><span class="pln">ajaxStart</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(){</span><span class="pln">
           count</span><span class="pun">++;</span><span class="pln">
           $</span><span class="pun">(</span><span class="str">"#stage2"</span><span class="pun">).</span><span class="pln">html</span><span class="pun">(</span><span class="str">"&lt;h1&gt;Starts, Count :"</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> count </span><span class="pun">+</span><span class="pln"> </span><span class="str">"&lt;/h1&gt;"</span><span class="pun">);</span><span class="pln">
        </span><span class="pun">});</span><span class="pln">
			
        </span><span class="com">/* Gets called when request complete */</span><span class="pln">
        $</span><span class="pun">(</span><span class="pln">document</span><span class="pun">).</span><span class="pln">ajaxComplete</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(</span><span class="pln">event</span><span class="pun">,</span><span class="pln">request</span><span class="pun">,</span><span class="kwd">set</span><span class="pun">){</span><span class="pln">
           count</span><span class="pun">++;</span><span class="pln">
           $</span><span class="pun">(</span><span class="str">"#stage3"</span><span class="pun">).</span><span class="pln">html</span><span class="pun">(</span><span class="str">"&lt;h1&gt;Completes,Count:"</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> count </span><span class="pun">+</span><span class="pln"> </span><span class="str">"&lt;/h1&gt;"</span><span class="pun">);</span><span class="pln">
        </span><span class="pun">});</span><span class="pln">
			
     </span><span class="pun">});</span><span class="pln">
  </span><span class="tag">&lt;/script&gt;</span><span class="pln">

</head>
<body>
<p>Click on the button to load result.html file:</p>
  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"stage1"</span><span class="pln"> </span><span class="atn">style</span><span class="pun">=</span><span class="atv">"</span><span class="pln">background</span><span class="pun">-</span><span class="pln">color</span><span class="pun">:</span><span class="pln">blue</span><span class="pun">;</span><span class="atv">"</span><span class="tag">&gt;</span><span class="pln">
     STAGE - 1
  </span><span class="tag">&lt;/div&gt;</span><span class="pln">
	
  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"stage2"</span><span class="pln"> </span><span class="atn">style</span><span class="pun">=</span><span class="atv">"</span><span class="pln">background</span><span class="pun">-</span><span class="pln">color</span><span class="pun">:</span><span class="pln">blue</span><span class="pun">;</span><span class="atv">"</span><span class="tag">&gt;</span><span class="pln">
     STAGE - 2
  </span><span class="tag">&lt;/div&gt;</span><span class="pln">
	
  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"stage3"</span><span class="pln"> </span><span class="atn">style</span><span class="pun">=</span><span class="atv">"</span><span class="pln">background</span><span class="pun">-</span><span class="pln">color</span><span class="pun">:</span><span class="pln">blue</span><span class="pun">;</span><span class="atv">"</span><span class="tag">&gt;</span><span class="pln">
     STAGE - 3
  </span><span class="tag">&lt;/div&gt;</span><span class="pln">
	
  </span><span class="tag">&lt;input</span><span class="pln"> </span><span class="atn">type</span><span class="pun">=</span><span class="atv">"button"</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"driver"</span><span class="pln"> </span><span class="atn">value</span><span class="pun">=</span><span class="atv">"Load Data"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">

</body>
</html>

这将产生以下输出-

无涯教程-jQuery - ajaxStart( callback )方法函数

ajaxStart( callback ) - 语法

ajaxStart( callback ) - 示例

参考链接