| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134 | <!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <title>Aisky-coffee</title>    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">    <!-- 新 Bootstrap4 核心 CSS 文件 -->    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.1.0/css/bootstrap.min.css">    <!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->    <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>    <!-- popper.min.js 用于弹窗、提示、下拉菜单 -->    <script src="https://cdn.bootcss.com/popper.js/1.12.5/umd/popper.min.js"></script>    <!-- 最新的 Bootstrap4 核心 JavaScript 文件 -->    <script src="https://cdn.bootcss.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>    <style>        /*多選下拉框樣式(根據自己的樣式調整)*/        .dropdown_item{            width: 100%;        }        .dropdown_item>li:HOVER{            background-color: #eee;            cursor: pointer;        }        .dropdown_item>li {            display: block;            padding: 3px 10px;            clear: both;            font-weight: normal;            line-height: 1.428571429;            color: #333;            white-space: nowrap;        }        .dropdown_item>li>.check_box{            width: 18px;            height: 18px;            vertical-align: middle;            margin: 0px;        }        .dropdown_item>li>span{            vertical-align: middle;        }        .select_multiple .caret{            border-top: 4px solid!important;            border-bottom: 0;        }    </style>    <script>        //多選下拉框實現    $(document).on("click",".check_box",function(event){		event.stopPropagation();//阻止事件冒泡,防止觸發li的點選事件		//勾選的項		var $selectTextDom=$(this).parent().parent("ul").siblings("button").children(".select_text");		//勾選項的值		var $selectValDom=$(this).parent().parent("ul").siblings(".select_val");		//是否有選擇項了		var isSelected=$selectTextDom[0].getAttribute("data-is-select");		var selectText="";//文字值,用於顯示		var selectVal=$selectValDom.val();//實際值,會提交到後臺的		var selected_text=$(this).siblings("span").text();//當次勾選的文字值		var selected_val=$(this).val();//當次勾選的實際值		//判斷是否選擇過		if(isSelected=="true"){			selectText=$selectTextDom.text();		}		if(selectText!=""){			if(selectText.indexOf(selected_text)>=0){//判斷是否已經勾選過				selectText=selectText.replace(selected_text,"").replace(",,",",");//替換掉				selectVal=selectVal.replace(selected_val,"").replace(",,",",");//替換掉				//判斷最後一個字元是否是逗號				if(selectText.charAt(selectText.length - 1)==","){					//去除末尾逗號					selectText=selectText.substring(0,selectText.length - 1);					selectVal=selectVal.substring(0,selectVal.length - 1);				}			}else{				selectText+=","+selected_text;				selectVal+=","+selected_val;			}		}else{			selectText=selected_text;			selectVal=selected_val;		}		$selectTextDom.text(selectText);		$selectValDom.val(selectVal);		if(selectText==""){			$selectTextDom.text("請選擇");			$selectTextDom[0].setAttribute("data-is-select","false");		}else{			$selectTextDom[0].setAttribute("data-is-select","true");		}	})    </script></head><body><div class="dropup" style="position: relative;">	<button class="btn btn-default dropdown-toggle form-control select_multiple" style="width: 20%;margin-left: 0px;" type="button" id="dropdownMenu21" data-toggle="dropdown">    	<span class="select_text" data-is-select="false">Dro pup</span>    	<span class="caret"></span>  	</button>  	<ul class="dropdown-menu dropdown_item" style="bottom: auto;">    	<li><input type="checkbox" class="check_box" value="aa" /> <span>Action</span></li>    	<li><input type="checkbox" class="check_box" value="bb"/> <span>Another action</span></li>    	<li><input type="checkbox" class="check_box" value="cc"/> <span>Something else here</span></li>    	<li><input type="checkbox" class="check_box" value="dd"/> <span>Separated link</span></li>  	</ul><!-- 為了方便演示,type設定text了,實際中可以設定成hidden -->	<input type="hidden" name="" class="select_val"/></div><select>    <!--<option>-->    <!--<ul class="dropdown-menu dropdown_item" style="bottom: auto;">-->    	<!--<li><input type="checkbox" class="check_box" value="aa" /> <span>Action</span></li>-->    	<!--<li><input type="checkbox" class="check_box" value="bb"/> <span>Another action</span></li>-->    	<!--<li><input type="checkbox" class="check_box" value="cc"/> <span>Something else here</span></li>-->    	<!--<li><input type="checkbox" class="check_box" value="dd"/> <span>Separated link</span></li>-->  	<!--</ul><!– 為了方便演示,type設定text了,實際中可以設定成hidden –>-->    <!--</option>-->    <option>red</option></select></body></html>
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