如何在Jquery中的DropDownList中获取空值? [英] How to get a Blank value in DropDownList in Jquery?
问题描述
Hello Team,
我在 jQuery
中有如下代码。
Hello Team,
I have the code as follows in jQuery
.
<select id="batchIDSelect" class="combo100">
<option>Select </option>
</select>
function GetDisplayBatchID() {
debugger;
$.ajax({
url: 'QCAllocation.aspx/GetDisplayBatchID',
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: "json",
success: function (result) {
debugger;
if (result.d != '') {
if (result.d != '' && result.d != null) {
DisplayBatchIDList = JSON.parse(result.d);
var drawRow = function (batchID) {
var dropdown = document.getElementById('batchIDSelect');
for (var i = 0; i < batchID.length; i++) {
var opt = document.createElement('option');
opt.innerHTML = batchID[i].BatchId;
dropdown.appendChild(opt);
}
}
drawRow(DisplayBatchIDList);
manageOverlay(false);
}
}
},
error: function (error) {
manageOverlay(false);
alert(error.responseText);
},
async: false
})
};
我在页面加载时调用 GetDisplayBatchID()
。在此,我在 DropDownList
中默认获得选择值。我想在页面加载时保持空白 DropDownList
。
怎么可能?
我想我们需要修改For循环,你能告诉我如何找到它吗? />
请指导我。
谢谢
Harshal
已更正格式和语法问题。
添加预
标签。
[/编辑]
I have call GetDisplayBatchID()
on page load. In This,I am getting "Select" value by default in DropDownList
.I want to keep blank DropDownList
when page load.
How it possible?
I think we need to modify the For Loop, will you show me how to find it ?
Please guide Me.
Thanks
Harshal
Corrected formatting and grammatical issues.
Added pre
tags.
[/Edit]
推荐答案
.ajax({
url:' QCAllocation.aspx / GetDisplayBatchID',
类型:' POST',
contentType:' application / json; charset = utf-8',
dataType:< span class =code-string> json,
成功: function (result){
debugger ;
if (result.d!= ' '){
if (result.d!= ' '&& result.d!= null ){
DisplayBatchIDList = JSON 跨度> .parse(result.d);
var drawRow = function (batchID){
var dropdown = document .getElementById(' batchIDSelect'跨度>);
for ( var i = 0 ; i< batchID.length; i ++){
var opt = document 。 createElement(' option');
opt.innerHTML = batchID [i] .BatchId;
dropdown.appendChild(opt);
}
}
drawRow(DisplayBatchIDList);
manageOverlay( false );
}
}
},
错误:功能(错误){
manageOverlay ( false );
alert(error.responseText);
},
async: false
})
};
.ajax({ url: 'QCAllocation.aspx/GetDisplayBatchID', type: 'POST', contentType: 'application/json; charset=utf-8', dataType: "json", success: function (result) { debugger; if (result.d != '') { if (result.d != '' && result.d != null) { DisplayBatchIDList = JSON.parse(result.d); var drawRow = function (batchID) { var dropdown = document.getElementById('batchIDSelect'); for (var i = 0; i < batchID.length; i++) { var opt = document.createElement('option'); opt.innerHTML = batchID[i].BatchId; dropdown.appendChild(opt); } } drawRow(DisplayBatchIDList); manageOverlay(false); } } }, error: function (error) { manageOverlay(false); alert(error.responseText); }, async: false }) };
我在页面加载时调用 GetDisplayBatchID()
。在此,我在 DropDownList
中默认获得选择值。我想在页面加载时保持空白 DropDownList
。
怎么可能?
我想我们需要修改For循环,你能告诉我如何找到它吗? />
请指导我。
谢谢
Harshal
已更正格式和语法问题。
添加预
标签。
[/编辑]
I have call GetDisplayBatchID()
on page load. In This,I am getting "Select" value by default in DropDownList
.I want to keep blank DropDownList
when page load.
How it possible?
I think we need to modify the For Loop, will you show me how to find it ?
Please guide Me.
Thanks
Harshal
Corrected formatting and grammatical issues.
Added pre
tags.
[/Edit]
尝试如下...
Try like below...
var dropdown = document.getElementById('batchIDSelect');
var opt = document.createElement('option');
opt.innerHTML = ""
dropdown.appendChild(opt);
for (var i = 0; i < batchID.length; i++) {
var opt = document.createElement('option');
opt.innerHTML = batchID[i].BatchId;
dropdown.appendChild(opt);
}
( #batchIDSelect option [value ='' ])。attr(' selected', true );
("#batchIDSelect option[value='']").attr('selected', true);
如果有效,请告诉我。
Let me know, if it works or not.
这篇关于如何在Jquery中的DropDownList中获取空值?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!