C# 如何基于ASP MVC中另一个DropDownList中选择的项目并使用Javascript从DropDownList中删除项目
我正在使用C#和SQLServer2005开发一个ASP.NETMVC3应用程序 在一个视图中,我有两个dropdownlist,它从基表中加载相同的值 我想创建一个事件,从DropDownList 2中删除DropdOnlist 1中选择的项目 代码如下:C# 如何基于ASP MVC中另一个DropDownList中选择的项目并使用Javascript从DropDownList中删除项目,c#,javascript,visual-studio-2010,asp.net-mvc-3,C#,Javascript,Visual Studio 2010,Asp.net Mvc 3,我正在使用C#和SQLServer2005开发一个ASP.NETMVC3应用程序 在一个视图中,我有两个dropdownlist,它从基表中加载相同的值 我想创建一个事件,从DropDownList 2中删除DropdOnlist 1中选择的项目 代码如下: <%:Html.Label("Poste :")%><%: Html.DropDownListFor(model => model.SelectedPoste, Model.PostesItems, new { @i
<%:Html.Label("Poste :")%><%: Html.DropDownListFor(model => model.SelectedPoste, Model.PostesItems, new { @id = "poste" })%>
<%:Html.Label("Poste Suivant :")%><%: Html.DropDownListFor(model => model.PosteSuivantSelected, Model.NextPS, new { @id = "dd" })%>
我认为问题在于:因为我没有在dropdownlist中定义“test3()”。您只需添加
onchange
属性,就像您在HTML助手中使用id
属性一样:
<%:Html.Label("Poste :")%><%: Html.DropDownListFor(model => model.SelectedPoste, Model.PostesItems, new { @id = "poste", onchange = "test3()" })%>
<%:Html.Label("Poste Suivant :")%><%: Html.DropDownListFor(model => model.PosteSuivantSelected, Model.NextPS, new { @id = "dd" })%>
然后,如果我们修改javascript,使其基于值(而不是索引)从第二个列表中删除该项,并添加一些代码来存储丢失的选项以重新添加,那么一切都应该正常工作:
var removedOption = null;
var removedOptionIndex = -1;
function test3() {
var dd = document.getElementById('dd');
var posteElement = document.getElementById('poste');
var currentValue = posteElement.options[posteElement.selectedIndex].value; // this will be the value of the selected option, '2' in this case: <option value="2">Two</option>
var currentText = posteElement.options[posteElement.selectedIndex].text; // this will be the text of the selected option, 'Two' in this case: <option value="2">Two</option>
// add the previously removed option back into the list in its previous position
if (removedOption != null) {
var newOpt = document.createElement("option");
newOpt.value = removedOption.value;
newOpt.innerHTML = removedOption.text;
if (removedOptionIndex < 0) removedOptionIndex = 0;
if (removedOptionIndex > dd.options.length) removedOptionIndex = dd.options.length;
insertOptionToSelect(dd, removedOptionIndex, newOpt);
removedOption = null;
}
for (var i = 0; i < dd.options.length; i++) // loop through all of dd's options
{
if (dd.options[i].value == currentValue) // use this if you want to compare by value
{
removedOption = dd.options[i];
removedOptionIndex = i;
dd.removeChild(dd.options[i]);
break;
}
if (dd.options[i].text == currentText) // use this if you want to compare by text
{
removedOption = dd.options[i];
removedOptionIndex = i;
dd.removeChild(dd.options[i]);
break;
}
}
}
function insertOptionToSelect(select, idx, option) {
var saved = [];
var i;
for (i = 0; i < select.options.length; i++) {
saved.push(select.options[i]);
}
select.options.length = 0;
for (i = 0; i < idx; i++) {
select.options[select.options.length] = saved[i];
}
select.options[select.options.length] = option;
while (i < saved.length) {
select.options[select.options.length] = saved[i++];
}
}
var removedOption=null;
var removedOptionIndex=-1;
函数test3(){
var dd=document.getElementById('dd');
var posteElement=document.getElementById('poste');
var currentValue=posteElement.options[posteElement.selectedIndex].value;//这将是所选选项“2”的值,在本例中为:2
var currentText=posteElement.options[posteElement.selectedIndex].text;//这将是所选选项的文本,在本例中为“Two”:Two
//将先前删除的选项添加回列表的先前位置
如果(removedOption!=null){
var newOpt=document.createElement(“选项”);
newOpt.value=removedOption.value;
newOpt.innerHTML=removedOption.text;
如果(removedOptionIndex<0)removedOptionIndex=0;
如果(removedOptionIndex>dd.options.length)removedOptionIndex=dd.options.length;
InsertOptionSelect(dd、removedOptionIndex、newOpt);
removedOption=null;
}
for(var i=0;i
感谢pizzamonster对这个问题的回答和他的insertoptionSelect
功能
要通过值或文本进行比较,只需使用适当的
if
语句,并随意删除其他变量以保持整洁。我给了你这两个选项,因为我自己是MVC新手,对呈现的HTML=]我不是100%确定。我已经编辑了我的答案,试试看。尽管有一件事非常突出,那就是如果用户选择了poste
中的每一项,那么dd
中就没有选项了。也许这应该只运行一次?或者,当所选项目在poste
中更改时,您可能需要在中添加其他内容以重新添加缺少的字段?再次感谢您的工作,很抱歉,我尝试了您的代码,但没有得到任何结果:((该项目仍然存在!关于您的备注,是的,它应该只删除一次,,,这意味着当我在poste中选择P1时,,,它应该从dd中临时删除,,,然后我在poste中选择P2,,,dd必须包含P1,但不包含P2,,,我希望您理解我:)我等待您的评论,Thx:)浏览器控制台中是否有错误?你能调试并逐步检查代码,看看哪里出了问题吗?不,没有错误。我无法在视图中放置断点:((好的,我的代码中有语法错误,我已更新了答案以反映。此代码成功地从select
元素中删除了该项。
<body onload="test3()">
var removedOption = null;
var removedOptionIndex = -1;
function test3() {
var dd = document.getElementById('dd');
var posteElement = document.getElementById('poste');
var currentValue = posteElement.options[posteElement.selectedIndex].value; // this will be the value of the selected option, '2' in this case: <option value="2">Two</option>
var currentText = posteElement.options[posteElement.selectedIndex].text; // this will be the text of the selected option, 'Two' in this case: <option value="2">Two</option>
// add the previously removed option back into the list in its previous position
if (removedOption != null) {
var newOpt = document.createElement("option");
newOpt.value = removedOption.value;
newOpt.innerHTML = removedOption.text;
if (removedOptionIndex < 0) removedOptionIndex = 0;
if (removedOptionIndex > dd.options.length) removedOptionIndex = dd.options.length;
insertOptionToSelect(dd, removedOptionIndex, newOpt);
removedOption = null;
}
for (var i = 0; i < dd.options.length; i++) // loop through all of dd's options
{
if (dd.options[i].value == currentValue) // use this if you want to compare by value
{
removedOption = dd.options[i];
removedOptionIndex = i;
dd.removeChild(dd.options[i]);
break;
}
if (dd.options[i].text == currentText) // use this if you want to compare by text
{
removedOption = dd.options[i];
removedOptionIndex = i;
dd.removeChild(dd.options[i]);
break;
}
}
}
function insertOptionToSelect(select, idx, option) {
var saved = [];
var i;
for (i = 0; i < select.options.length; i++) {
saved.push(select.options[i]);
}
select.options.length = 0;
for (i = 0; i < idx; i++) {
select.options[select.options.length] = saved[i];
}
select.options[select.options.length] = option;
while (i < saved.length) {
select.options[select.options.length] = saved[i++];
}
}