The
select element creates a single-select or multiple-select menu. When submitting a form, the browser will submit the selected items, or collect multiple options separated by commas. The following is an example of its specific usage. The select element creates single-select or multiple-select menus. When the form is submitted, the browser submits the selected items, or collects multiple comma-separated options, combines them into a single parameter list, and includes the name attribute when submitting the
The code is as follows:
Among them, the tag can be omitted and used in the page
The code is as follows:
2. The Select element can also be used for multiple selections, see the following code:
The code is as follows:
//有multiple属性，则可以多选 //下面没有multiple属性 , 只显示一条，不能多选 //下面是设置了size属性的情况 , 如果size = 3 那么就显示三条数据，注意不能多选的。
3. All common operations involved in the multi-select Select component:
1. Determine whether there is an Item with a specified value in the select option
The code is as follows:
@param objSelectId 将要验证的目标select组件的id
@param objItemValue 将要验证是否存在的值
function isSelectItemExit(objSelectId,objItemValue) {
var objSelect = document.getElementById(objSelectId);
var isExit = false;
if (null != objSelect && typeof(objSelect) != "undefined") {
for(var i=0;iCopy after login
2. Add an Item to the select option
The code is as follows:
@param objSelectId 将要加入item的目标select组件的id
@param objItemText 将要加入的item显示的内容
@param objItemValue 将要加入的item的值
function addOneItemToSelect(objSelectId,objItemText,objItemValue) {
var objSelect = document.getElementById(objSelectId);
if (null != objSelect && typeof(objSelect) != "undefined") {
//判断是否该值的item已经在select中存在
if(isSelectItemExit(objSelectId,objItemValue)) {
$.messager.alert('提示消息','该值的选项已经存在!','info');
} else {
var varItem = new Option(objItemText,objItemValue);
objSelect.options.add(varItem);
}
}
}
3. Delete the selected item from the select option, support multiple selections and multiple deletions
The code is as follows:
@param objSelectId 将要进行删除的目标select组件id
function removeSelectItemsFromSelect(objSelectId) {
var objSelect = document.getElementById(objSelectId);
var delNum = 0;
if (null != objSelect && typeof(objSelect) != "undefined") {
for(var i=0;iCopy after login
4. Delete an Item from the select option according to the specified value
The code is as follows:
@param objSelectId 将要验证的目标select组件的id
@param objItemValue 将要验证是否存在的值
function removeItemFromSelectByItemValue(objSelectId,objItemValue) {
var objSelect = document.getElementById(objSelectId);
if (null != objSelect && typeof(objSelect) != "undefined") {
//判断是否存在
if(isSelectItemExit(objSelect,objItemValue)) {
for(var i=0;iCopy after login
5. Clear all options in the select
The code is as follows:
@param objSelectId 将要进行清空的目标select组件id
function clearSelect(objSelectId) {
var objSelect = document.getElementById(objSelectId);
if (null != objSelect && typeof(objSelect) != "undefined") {
for(var i=0;iCopy after login
6. Get all the items in the select and assemble all values into one character String, separated by commas between values
The code is as follows:
@param objSelectId 目标select组件id
@return select中所有item的值，值与值之间用逗号隔开
function getAllItemValuesByString(objSelectId) {
var selectItemsValuesStr = "";
var objSelect = document.getElementById(objSelectId);
if (null != objSelect && typeof(objSelect) != "undefined") {
var length = objSelect.options.length
for(var i = 0; i < length; i = i + 1) {
if (0 == i) {
selectItemsValuesStr = objSelect.options[i].value;
} else {
selectItemsValuesStr = selectItemsValuesStr + "," + objSelect.options[i].value;
}
}
}
return selectItemsValuesStr;
}
7. Move all selected options in one select to another select Go
The code is as follows:
@param fromObjSelectId 移动item的原select组件id
@param toObjectSelectId 移动item将要进入的目标select组件id
function moveAllSelectedToAnotherSelectObject(fromObjSelectId, toObjectSelectId) {
var objSelect = document.getElementById(fromObjSelectId);
var delNum = 0;
if (null != objSelect && typeof(objSelect) != "undefined") {
for(var i=0;iCopy after login
8. Move all options in one select to another select
The code is as follows :
@param fromObjSelectId 移动item的原select组件id
@param toObjectSelectId 移动item将要进入的目标select组件id
function moveAllToAnotherSelectObject(fromObjSelectId, toObjectSelectId) {
var objSelect = document.getElementById(fromObjSelectId);
if (null != objSelect) {
for(var i=0;iCopy after login For more detailed introduction to the single-select and multi-select usage of the select tag in HTML, please pay attention to the PHP Chinese website for related articles!
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