我已经动态创建了一些选择控件（a.k.a.groupbox），但每次我尝试访问其中一个控件时如果出现以下错误：
Uncaught TypeError: undefined is not a function
以下是代码：
var method =$("#slt" + (parseInt(buttonElementId + 1))).children("option").is("selected").text();
parseInt(buttonElementId + 1总是一个数字，所以错误不存在
<html>
<head lang="en">
<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.2/css/bootstrap.min.css"> <!-- load bootstrap css -->
<link rel="stylesheet" href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.min.css"> <!-- load fontawesome -->
<style>
body { padding-top:80px; }
html, body, #wrapper
{
width: 100%;
height: 100%;
}
</style>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<div class="container">
<div id="information"></div>
<div id="tableInformation"></div>
<div id="goBack"></div>
<br/>
<div id="inputDiv"></div>
<br/>
<br/>
<div id="UserGuide"></div>
</div>
<script src="js/jquery-1.11.js"> </script>
<script>
var apiUrl = 'http://localhost/devices';
$( document ).ready(function() {
// Handler for .ready() called.
jsonGETRequest(apiUrl, jsonExampleData);
});
$(document).on('click', ':button' , function() {
// reference clicked button via: $(this)
$("#UserGuide").empty();
var buttonElementId = $(this).attr('id');
if(buttonElementId.indexOf("btnShowFunc") > -1) {
buttonElementId = buttonElementId.replace("btnShowFunc","");
deviceUID = document.getElementById("mytable").rows[(parseInt(buttonElementId) + 1)].cells[1].innerHTML;
goBack = "firstAPIRequest";
$("#tableInformation tbody").remove();
jsonGETRequest(apiUrl + "/" + deviceUID + "/functions", jsonExampleDataFunctions);
} else if(buttonElementId.indexOf("btnGoBack") > -1 ) {
switch (goBack) {
case "firstAPIRequest":
goBack = "";
$("#tableInformation tbody").remove();
jsonGETRequest(apiUrl, jsonExampleData);
removeGoBackInputDiv();
break;
case "secondAPIRequest":
goBack = "firstAPIRequest";
$("#tableInformation tbody").remove();
jsonGETRequest(apiUrl + "/" + deviceUID + "/functions", jsonExampleDataFunctions);
removeGoBackInputDiv();
break;
}
}else if(buttonElementId.indexOf("btnRunFunc") > -1) {
goBack = "secondAPIRequest";
buttonElementId = buttonElementId.replace("btnRunFunc","");
var functionUID = document.getElementById("mytable").rows[(parseInt(buttonElementId) +1)].cells[2].innerHTML;
var method =$("#slt" + (parseInt(buttonElementId + 1))).children("option").is("selected").text();
$("#tableInformation tbody").remove();
$("#inputDiv").empty();
// /jsonPOST(apiUrl '/functions/' + functionUID )
}
});
function loadDataIntoDeviceGrid(jsonData) {
//$("#tableInformation").addClass("table table-responsive table-bordered");
var tbl=$("<table/>").attr("id","mytable");
$("#tableInformation").append(tbl);
$("#mytable").append("<tr>" + "<th>dal.device.status</th>" + "<th>dal.device.UID</th>"
+ "<th>dal.device.driver</th>" + "<th>service.id</th>" +"<th></th>" + "</tr>");
for(var i=0;i<jsonData.length;i++)
{
var tr = "<tr>";
var td1 = "<td>"+jsonData[i]["dal.device.status"]+"</td>";
var td2 = "<td>"+jsonData[i]["dal.device.UID"]+"</td>";
var td3 = "<td>"+jsonData[i]["dal.device.driver"]+"</td>";
var td4 = "<td>"+jsonData[i]["service.id"]+"</td>";
//@Deprecated var dataList = fillSelectControl(jsonData[i]["objectClass"]); @Deprecated
var btn = "<td>" + "<button id='btnShowFunc"+ i + "' class='btn btn-success btn-lg'>See function</button>" + "</td></tr>";
$("#mytable").append(tr + td1 + td2 + td3 + td4 + btn );
}
$("#mytable").addClass("table table-responsive table-bordered");
}
function loadInformationDeviceGrid() {
$("#UserGuide").addClass("alert alert-info");
$("#UserGuide").html("<h3>Getting devices list:</h3><br/> "+
"Using this request, you can retrieve a list of all the available devices."+
"For every device, among other info, there is the indication of the device unique ID, which" +
"can be used to directly access to the device and the indication of the device driver (ZigBee, Bluetooth, etc.).<br/>If you want see some request response example please visit this <a href='#'>site</a>");
}
function removeGoBackInputDiv() {
$("#inputDiv").empty();
$("#btnGoBack").remove();
}
function loadDataIntoFunctionsGrid(jsonData) {
$("#mytable").append("<tr>" + "<th>function.device.UID</th>"
+ "<th>service.id</th>" + "<th>function.UID</th>" + "<th>operation.names</th>" + "<th></th>" + "</tr>");
var tr, td2, td3, td4, dt2, btn;
for(var i = 0; i < jsonData.length; i++) {
tr = "<tr>";
//@Deprecated td1 = "<td>" + jsonData[i]["CLASS"] + "</td>";
td2 = "<td>" + jsonData[i]["al.function.device.UID"] + "</td>";
td3 = "<td>" + jsonData[i]["service.id"] + "</td>";
td4 = "<td>" + jsonData[i]["dal.function.UID"] + "</td>";
//@Deprecated dt1 = fillSelectControl(jsonData[i]["objectClass"]);
dt2 = fillSelectControl(jsonData[i]["dal.function.operation.names"], i);
btn = "<td>" + "<button id='btnRunFunc"+ i + "' class='btn btn-success btn-lg'>Run</button>" + "</td></tr>";
$("#mytable").append(tr + td2 + td3 + td4 + dt2 + btn );
}
createGoBackButton();
createInputTextParameters();
}
function loadInformationFunctionsGrid() {
$("#UserGuide").addClass("alert alert-info");
$("#UserGuide").html("<h3>Getting device functions:</h3><br/>"
+ "This API is used to retrieve the list of the available functions supported by the device. For"
+ "example a Smart Plug has two functions: one to retrieve the energy consumption and another"
+ "'boolean' function useful to change the status of the smart plug (ON/OFF). Every function"
+ "indicates the id, which can be used to access directly the function and the list of the operation"
+ "that can be invoked on the function.<br/>"
+ "P.S. If he want use a function that want some parameters he must write these into the dedicated textbox. If the API needs more parameters separate these using comma. <br/>"
+ "Example of parametes: <br/> <code>'type':'java.math.BigDecimal'</code><br/> <code>'value':1</code> <br/> etc...");
}
function createGoBackButton() {
var btn = '<button id="btnGoBack" class="btn btn-warning btn-lg">Go Back</button>';
$("#goBack").append(btn);
}
function createInputTextParameters() {
var lbl ="<label>Paramters</label>";
var txt ='<input type="text" class="form-control" name="email">';
$("#inputDiv").addClass("form-group");
$("#inputDiv").append(lbl);
$("#inputDiv").append(txt);
}
function fillSelectControl(obj, id) {
var dataList = "<td><select id='slt"+ id +"'>";
for(var j = 0; j < obj.length; j++)
dataList = dataList + "<option value='" + obj[j] + "'>" + obj[j] + "</option>";
return dataList = dataList + "</select></td>";
}
var json = "";
var goBack = "";
var deviceUID;
function jsonGETRequest(url, dataExample){
$.getJSON(apiUrl, function(data) {
alert(JSON.stringify(data));
this.json = data;
})
.done(function() {
$("#information").addClass("alert alert-success");
$("#information").text("getJSON request succeeded!");
if(goBack == "") {
loadDataIntoDeviceGrid(jsonExampleData);
loadInformationDeviceGrid();
} else if (goBack=="firstAPIRequest") {
loadDataIntoFunctionsGrid(jsonExampleDataFunctions);
loadInformationDeviceGrid();
}
})
.fail(function(jqXHR, textStatus, errorThrown) {
//alert('getJSON request failed! ' + textStatus);
$("#information").addClass("alert alert-danger");
$("#information").text("Impossible get data from API, it will be use example data" + errorThrown);
if(goBack == "") {
loadDataIntoDeviceGrid(jsonExampleData);
loadInformationDeviceGrid();
} else if (goBack=="firstAPIRequest") {
loadDataIntoFunctionsGrid(jsonExampleDataFunctions);
loadInformationFunctionsGrid();
} else if(goBack=="secondAPIRequest") {
}
})
.always(function() { });
}
function jsonPOST(url, method, paramters, dataExample) {
}
var jsonExampleData = [
{
"dal.device.status": 2,
"dal.device.UID": "ZigBee:test123",
"dal.device.driver": "ZigBee",
"service.id": 28,
"objectClass": [
"org.osgi.service.dal.Device"
]
},
{
"dal.device.status": 2,
"dal.device.UID": "ZigBee:test456",
"dal.device.driver": "ZigBee",
"service.id": 29,
"objectClass": [
"org.osgi.service.dal.Device"
]
},
{
"dal.device.status": 2,
"dal.device.UID": "ZigBee:test789",
"dal.device.driver": "ZigBee",
"service.id": 30,
"objectClass": [
"org.osgi.service.dal.Device"
]
}
];
var jsonExampleDataFunctions = [
{
"CLASS": "ismb.pert.jemma.dummydevice.DummyFunction",
"dal.function.device.UID": "ZigBee:test123",
"service.id": 27,
"dal.function.UID": "ZigBee:test123:testButton",
"objectClass": [
"org.osgi.service.dal.Function"
],
"dal.function.operation.names": [
"getData",
"reverse",
"setFalse",
"setTrue"
]
},
{
"CLASS": "ismb.pert.jemma.dummydevice.DummyFunction",
"dal.function.device.UID": "ZigBee:test456",
"service.id": 26,
"dal.function.UID": "ZigBee:test456:testButton",
"objectClass": [
"org.osgi.service.dal.Function"
],
"dal.function.operation.names": [
"getData",
"reverse",
"setFalse",
"setTrue"
]
},
{
"CLASS": "ismb.pert.jemma.dummydevice.DummyFunction",
"dal.function.device.UID": "ZigBee:test789",
"service.id": 25,
"dal.function.UID": "ZigBee:test789:testButton",
"objectClass": [
"org.osgi.service.dal.Function"
],
"dal.function.operation.names": [
"getData",
"reverse",
"setFalse",
"setTrue"
]
}
];
</script>
</body>
</html>
答案 0 :(得分：1)
.is()返回一个true / false值，它不会继续jQuery链，因此没有.text()函数可以调用
正如DevishOne在评论中指出的那样，获取所选选项的文本：
=$("#slt" + (parseInt(buttonElementId + 1))).children("option:selected").text();
答案 1 :(得分：0)
将其拆分为多个步骤并检查特定结果：
button = $("#slt" + (parseInt(buttonElementId + 1)));
if ( button )
{
childs = button.children("option");
if ( childs .....
如果没有选择任何选项，则无法捕捉到该选项，因为您直接引用方法.text()为null。