我想为产品创建一个条形码扫描仪。 我已经看到了答案：
$(document).ready(function() {
var barcode="";
$(document).keydown(function(e) {
var code = (e.keyCode ? e.keyCode : e.which);
if(code==13)// Enter key hit
{
alert(barcode);
}
else if(code==9)// Tab key hit
{
alert(barcode);
}
else
{
barcode=barcode+String.fromCharCode(code);
}
});
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>因此，当我尝试该代码时，我按下rando键，然后输入。 然后代码显示键，我先按。 以前有人说过，条形码就像键盘一样工作。
但是我现在如何创建扫描仪，扫描产品和(如果可能( 看到产品名称了吗？ 还是这段代码只是不是代码，我需要它和其他东西？
你可以在HTML页面中使用JS。
对于条形码扫描，您需要一个barcodescanner.js文件：
(function ($) {
$.fn.scannerDetection = function (options) {
// If string given, call onComplete callback
if (typeof options === "string") {
this.each(function () {
this.scannerDetectionTest(options);
});
return this;
}
// If false (boolean) given, deinitialize plugin
if (options === false) {
this.each(function () {
this.scannerDetectionOff();
});
return this;
}
var defaults = {
onComplete: false, // Callback after detection of a successfull scanning (scanned string in parameter)
onError: false, // Callback after detection of a unsuccessfull scanning (scanned string in parameter)
onReceive: false, // Callback after receiving and processing a char (scanned char in parameter)
onKeyDetect: false, // Callback after detecting a keyDown (key char in parameter) - in contrast to onReceive, this fires for non-character keys like tab, arrows, etc. too!
timeBeforeScanTest: 100, // Wait duration (ms) after keypress event to check if scanning is finished
avgTimeByChar: 30, // Average time (ms) between 2 chars. Used to do difference between keyboard typing and scanning
minLength: 6, // Minimum length for a scanning
endChar: [9, 13], // Chars to remove and means end of scanning
startChar: [], // Chars to remove and means start of scanning
ignoreIfFocusOn: false, // do not handle scans if the currently focused element matches this selector
scanButtonKeyCode: false, // Key code of the scanner hardware button (if the scanner button a acts as a key itself)
scanButtonLongPressThreshold: 3, // How many times the hardware button should issue a pressed event before a barcode is read to detect a longpress
onScanButtonLongPressed: false, // Callback after detection of a successfull scan while the scan button was pressed and held down
stopPropagation: false, // Stop immediate propagation on keypress event
preventDefault: false // Prevent default action on keypress event
};
if (typeof options === "function") {
options = { onComplete: options }
}
if (typeof options !== "object") {
options = $.extend({}, defaults);
} else {
options = $.extend({}, defaults, options);
}
this.each(function () {
var self = this, $self = $(self), firstCharTime = 0, lastCharTime = 0, stringWriting = '', callIsScanner = false, testTimer = false, scanButtonCounter = 0;
var initScannerDetection = function () {
firstCharTime = 0;
stringWriting = '';
scanButtonCounter = 0;
};
self.scannerDetectionOff = function () {
$self.unbind('keydown.scannerDetection');
$self.unbind('keypress.scannerDetection');
}
self.isFocusOnIgnoredElement = function () {
if (!options.ignoreIfFocusOn) return false;
if (typeof options.ignoreIfFocusOn === 'string') return $(':focus').is(options.ignoreIfFocusOn);
if (typeof options.ignoreIfFocusOn === 'object' && options.ignoreIfFocusOn.length) {
var focused = $(':focus');
for (var i = 0; i < options.ignoreIfFocusOn.length; i++) {
if (focused.is(options.ignoreIfFocusOn[i])) {
return true;
}
}
}
return false;
}
self.scannerDetectionTest = function (s) {
// If string is given, test it
if (s) {
firstCharTime = lastCharTime = 0;
stringWriting = s;
}
if (!scanButtonCounter) {
scanButtonCounter = 1;
}
// If all condition are good (length, time...), call the callback and re-initialize the plugin for next scanning
// Else, just re-initialize
if (stringWriting.length >= options.minLength && lastCharTime - firstCharTime < stringWriting.length * options.avgTimeByChar) {
if (options.onScanButtonLongPressed && scanButtonCounter > options.scanButtonLongPressThreshold) options.onScanButtonLongPressed.call(self, stringWriting, scanButtonCounter);
else if (options.onComplete) options.onComplete.call(self, stringWriting, scanButtonCounter);
$self.trigger('scannerDetectionComplete', { string: stringWriting });
initScannerDetection();
return true;
} else {
if (options.onError) options.onError.call(self, stringWriting);
$self.trigger('scannerDetectionError', { string: stringWriting });
initScannerDetection();
return false;
}
}
$self.data('scannerDetection', { options: options }).unbind('.scannerDetection').bind('keydown.scannerDetection', function (e) {
// If it's just the button of the scanner, ignore it and wait for the real input
if (options.scanButtonKeyCode !== false && e.which == options.scanButtonKeyCode) {
scanButtonCounter++;
// Cancel default
e.preventDefault();
e.stopImmediatePropagation();
}
// Add event on keydown because keypress is not triggered for non character keys (tab, up, down...)
// So need that to check endChar and startChar (that is often tab or enter) and call keypress if necessary
else if ((firstCharTime && options.endChar.indexOf(e.which) !== -1)
|| (!firstCharTime && options.startChar.indexOf(e.which) !== -1)) {
// Clone event, set type and trigger it
var e2 = jQuery.Event('keypress', e);
e2.type = 'keypress.scannerDetection';
$self.triggerHandler(e2);
// Cancel default
e.preventDefault();
e.stopImmediatePropagation();
}
// Fire keyDetect event in any case!
if (options.onKeyDetect) options.onKeyDetect.call(self, e);
$self.trigger('scannerDetectionKeyDetect', { evt: e });
}).bind('keypress.scannerDetection', function (e) {
if (this.isFocusOnIgnoredElement()) return;
if (options.stopPropagation) e.stopImmediatePropagation();
if (options.preventDefault) e.preventDefault();
if (firstCharTime && options.endChar.indexOf(e.which) !== -1) {
e.preventDefault();
e.stopImmediatePropagation();
callIsScanner = true;
} else if (!firstCharTime && options.startChar.indexOf(e.which) !== -1) {
e.preventDefault();
e.stopImmediatePropagation();
callIsScanner = false;
} else {
if (typeof (e.which) != 'undefined') {
stringWriting += String.fromCharCode(e.which);
}
callIsScanner = false;
}
if (!firstCharTime) {
firstCharTime = Date.now();
}
lastCharTime = Date.now();
if (testTimer) clearTimeout(testTimer);
if (callIsScanner) {
self.scannerDetectionTest();
testTimer = false;
} else {
testTimer = setTimeout(self.scannerDetectionTest, options.timeBeforeScanTest);
}
if (options.onReceive) options.onReceive.call(self, e);
$self.trigger('scannerDetectionReceive', { evt: e });
});
});
return this;
}
})(jQuery);
对于HTML内部的用例：
<script type="text/javascript">
$(document).scannerDetection({
timeBeforeScanTest: 200, // wait for the next character for upto 200ms
startChar: [120], // Prefix character for the cabled scanner (OPL6845R)
endChar: [13], // be sure the scan is complete if key 13 (enter) is detected
avgTimeByChar: 40, // it's not a barcode if a character takes longer than 40ms
onComplete: function(barcode, qty) {
console.log(barcode);
console.log(qty);
// barcode number code
// qty scanned by barcode scanner
},
onKeyDetect: function(event) {
return false;
}
});
</script>