Javascript 读取当前文本输入值后的Ajax调用
为了从手持式条形码扫描仪中读取值,我遵循这个答案。代码工作正常,如答案所述(fiddle附在上面的链接中) 然而,我试图做的是在读取条形码后,根据文本输入的当前值进行一些ajax调用 我面临的问题是,如果我多次扫描条形码,在按下按钮(触发ajax调用)后,我会进行相同次数的ajax调用。例如,如果我读了4个条形码,我会进行4次相同的ajax调用(在我的例子中)。我要做的是按下按钮后只打一个电话,但只从文本输入框中读取最新的值 每次扫描条形码时,文本输入框都会显示新值(以前的值会被覆盖)。但是,ajax调用在按下Javascript 读取当前文本输入值后的Ajax调用,javascript,jquery,ajax,Javascript,Jquery,Ajax,为了从手持式条形码扫描仪中读取值,我遵循这个答案。代码工作正常,如答案所述(fiddle附在上面的链接中) 然而,我试图做的是在读取条形码后,根据文本输入的当前值进行一些ajax调用 我面临的问题是,如果我多次扫描条形码,在按下按钮(触发ajax调用)后,我会进行相同次数的ajax调用。例如,如果我读了4个条形码,我会进行4次相同的ajax调用(在我的例子中)。我要做的是按下按钮后只打一个电话,但只从文本输入框中读取最新的值 每次扫描条形码时,文本输入框都会显示新值(以前的值会被覆盖)。但是,a
#scanner verify按钮
按钮时也会触发之前的所有扫描
这是我用自定义ajax调用修改的
/*
This code will determine when a code has been either entered manually or
entered using a scanner.
It assumes that a code has finished being entered when one of the following
events occurs:
• The enter key (keycode 13) is input
• The input has a minumum length of text and loses focus
• Input stops after being entered very fast (assumed to be a scanner)
*/
var inputStart, inputStop, firstKey, lastKey, timing, userFinishedEntering;
var minChars = 3;
// handle a key value being entered by either keyboard or scanner
$("#scanInput").keypress(function(e) {
// restart the timer
if (timing) {
clearTimeout(timing);
}
// handle the key event
if (e.which == 13) {
// Enter key was entered
// don't submit the form
e.preventDefault();
// has the user finished entering manually?
if ($("#scanInput").val().length >= minChars) {
userFinishedEntering = true; // incase the user pressed the enter key
inputComplete();
}
} else {
// some other key value was entered
// could be the last character
inputStop = performance.now();
lastKey = e.which;
// don't assume it's finished just yet
userFinishedEntering = false;
// is this the first character?
if (!inputStart) {
firstKey = e.which;
inputStart = inputStop;
// watch for a loss of focus
$("body").on("blur", "#scanInput", inputBlur);
}
// start the timer again
timing = setTimeout(inputTimeoutHandler, 500);
}
});
// Assume that a loss of focus means the value has finished being entered
function inputBlur() {
clearTimeout(timing);
if ($("#scanInput").val().length >= minChars) {
userFinishedEntering = true;
inputComplete();
}
};
// reset the page
$("#reset").click(function(e) {
e.preventDefault();
resetValues();
});
function resetValues() {
// clear the variables
inputStart = null;
inputStop = null;
firstKey = null;
lastKey = null;
// clear the results
inputComplete();
}
// Assume that it is from the scanner if it was entered really fast
function isScannerInput() {
return (((inputStop - inputStart) / $("#scanInput").val().length) < 15);
}
// Determine if the user is just typing slowly
function isUserFinishedEntering() {
return !isScannerInput() && userFinishedEntering;
}
function inputTimeoutHandler() {
// stop listening for a timer event
clearTimeout(timing);
// if the value is being entered manually and hasn't finished being entered
if (!isUserFinishedEntering() || $("#scanInput").val().length < 3) {
// keep waiting for input
return;
} else {
reportValues();
}
}
// here we decide what to do now that we know a value has been completely entered
function inputComplete() {
// stop listening for the input to lose focus
$("body").off("blur", "#scanInput", inputBlur);
// report the results
reportValues();
}
function reportValues() {
// update the metrics
$("#startTime").text(inputStart == null ? "" : inputStart);
$("#firstKey").text(firstKey == null ? "" : firstKey);
$("#endTime").text(inputStop == null ? "" : inputStop);
$("#lastKey").text(lastKey == null ? "" : lastKey);
$("#totalTime").text(inputStart == null ? "" : (inputStop - inputStart) + " milliseconds");
if (!inputStart) {
// clear the results
$("#resultsList").html("");
$("#scanInput").focus().select();
} else {
// prepend another result item
var inputMethod = isScannerInput() ? "Scanner" : "Keyboard";
$("#resultsList").prepend("<div class='resultItem " + inputMethod + "'>" +
"<span>Value: " + $("#scanInput").val() + "<br/>" +
"<span>ms/char: " + ((inputStop - inputStart) / $("#scanInput").val().length) + "</span></br>" +
"<span>InputMethod: <strong>" + inputMethod + "</strong></span></br>" +
"</span></div></br>");
$("#scanInput").focus().select();
inputStart = null;
// Some transformations
const barcodeString = $("#scanInput").val();
const productCode = barcodeString.substring(5, 19);
const serialNumber = barcodeString.substring(36, 46);
const batch = barcodeString.substring(29, 34);
const expirationDate = barcodeString.substring(21, 27);
// AJAX calls
$('#scanner-verify-button').click(function() {
$.ajax({
url: "DecodeScanner",
type: "POST",
data: {
productCode: productCode,
serialNumber: serialNumber,
batch: batch,
expirationDate: expirationDate,
commandStatusCode: 0
},
async: true,
success: function(data) {
$('#pTextAreaResult').text(data);
}
});
});
}
}
$("#scanInput").focus();
/*
此代码将确定何时手动或手动输入代码
使用扫描仪输入。
它假定在下列情况之一时,代码已输入完毕
发生的事件:
•输入输入键(键代码13)
•输入的文本长度最小,失去焦点
•输入速度非常快(假设为扫描仪)后停止输入
*/
var inputStart、inputStop、firstKey、lastKey、timing、userFinishedEntering;
var-minChars=3;
//处理键盘或扫描仪输入的键值
$(“#扫描输入”)。按键(功能(e){
//重新启动计时器
如果(定时){
清除超时(定时);
}
//处理关键事件
如果(e.which==13){
//输入了回车键
//不要提交表格
e、 预防默认值();
//用户是否已完成手动输入?
if($(“#scanInput”).val().length>=minChars){
userFinishedEntering=true;//如果用户按了enter键
inputComplete();
}
}否则{
//输入了其他一些键值
//可能是最后一个角色
inputStop=performance.now();
lastKey=e.which;
//不要以为它刚刚完成
userFinishedEntering=false;
//这是第一个角色吗?
如果(!inputStart){
firstKey=e.which;
输入开始=输入停止;
//注意注意力不集中
$(“正文”)。在(“模糊”、“扫描输入”、“输入模糊”);
}
//再次启动计时器
计时=设置超时(inputTimeoutHandler,500);
}
});
//假设失去焦点意味着该值已输入完毕
函数inputBlur(){
清除超时(定时);
if($(“#scanInput”).val().length>=minChars){
userFinishedEntering=true;
inputComplete();
}
};
//重新设置页面
$(“#重置”)。单击(功能(e){
e、 预防默认值();
重置值();
});
函数resetValues(){
//清除变量
inputStart=null;
inputStop=null;
firstKey=null;
lastKey=null;
//清除结果
inputComplete();
}
//如果输入速度非常快,则假定它来自扫描仪
函数isScannerInput(){
返回(((inputStop-inputStart)/$(“#scanInput”).val().length)<15);
}
//确定用户是否只是在缓慢地键入
函数isUserFinishedEntering(){
return!isScannerInput()&&userFinishedEntering;
}
函数inputTimeoutHandler(){
//停止侦听计时器事件
清除超时(定时);
//如果该值是手动输入的,但尚未完成输入
如果(!isUserFinishedEntering()| |$(“#scanInput”).val().length<3){
//继续等待输入
返回;
}否则{
reportValues();
}
}
//在这里,我们决定现在要做什么,因为我们知道已经完全输入了一个值
函数inputComplete(){
//停止收听,以使输入失去焦点
$(“body”).off(“模糊”,“扫描输入”,输入模糊);
//报告结果
reportValues();
}
函数reportValues(){
//更新指标
$(“#开始时间”).text(inputStart==null?”:inputStart);
$(“#firstKey”).text(firstKey==null?”:firstKey);
$(“#endTime”).text(inputStop==null?”:inputStop);
$(“#lastKey”).text(lastKey==null?”:lastKey);
$(“#totalTime”).text(inputStart==null?”:(inputStop-inputStart)+“毫秒”);
如果(!inputStart){
//清除结果
$(“#结果列表”).html(“”);
$(“#扫描输入”).focus().select();
}否则{
//预加另一个结果项
var inputMethod=isScannerInput()?“扫描仪”:“键盘”;
$(“#结果列表”).prepend(”+
“值:”+$(“#scanInput”).val()+“
”+
“ms/char:”+((inputStop-inputStart)/$(“#scanInput”).val().length)+“”+
“InputMethod:“+InputMethod+””+
“”;
$(“#扫描输入”).focus().select();
inputStart=null;
//一些转变
常量条形码字符串=$(“#扫描输入”).val();
const productCode=barcodeString.substring(5,19);
const serialNumber=条形码字符串.子字符串(36,46);
const batch=条形码字符串.子字符串(29,34);
const expirationDate=barcodeString.substring(21,27);
//AJAX调用
$(“#扫描仪验证按钮”)。单击(函数(){
$.ajax({
url:“解码扫描程序”,
类型:“POST”,
数据:{
productCode:productCode,
serialNumber:serialNumber,
批次:批次,
到期日期:到期日期,
commandStatusCode:0
},
async:true,
成功:功能(数据){
$('pTextAreaResult')。文本(数据);
}
});
});
}
}
$(“#scanInput”).focus();
HTML
重置
事件信息开始:
第一个键:
最后一天:
结束:
结果
验证
根据代码,扫描仪按钮的单击处理程序似乎已注册多次
单击处理程序应该
<form>
<input id="scanInput" />
<button id="reset">Reset</button>
</form>
<br/>
<div>
<h2>Event Information</h2> Start: <span id="startTime"></span>
<br/>First Key: <span id="firstKey"></span>
<br/>Last Ley: <span id="lastKey"></span>
<br/>End: <span id="endTime"></span>
<br/>Elapsed: <span id="totalTime"></span>
</div>
<div>
<h2>Results</h2>
<div id="resultsList"></div>
</div>
<div class="col-sm-12">
<button id="scanner-verify-button" type="submit">Verify</button>
</div>
// Check for any input changes
var productCode, serialNumber, batch, expirationDate;
$("#scanInput").on("change paste keyup", function () {
barcodeString = $("#scanInput").val();
productCode = barcodeString.substring(5, 19);
serialNumber = barcodeString.substring(36, 46);
batch = barcodeString.substring(29, 34);
expirationDate = barcodeString.substring(21, 27);
});
// Ajax calls
$("#scanner-verify-button").click(function () {
$.ajax({
url: "DecodeScanner",
type: "POST",
data: {
productCode: productCode,
serialNumber: serialNumber,
batch: batch,
expirationDate: expirationDate,
commandStatusCode: 0
},
async: true,
success: function (data) {
$('#pTextAreaResult').text(data);
}
});
});