javascript - allow textbox input from barcode scanner only and restrict any input from keyboard

Question

There is functionality like, the textbox accepts input from only barcode scanner and restricts any other input from keyboard.

Answer 1

以下是限制键盘输入..只需尝试连接您的条形码扫描仪并检查它是否有效..

 textBox.onkeypress = function(e) {
       e = e || window.event;
       var charCode = (typeof e.which == "number") ? e.which : e.keyCode;
       if (/\D/.test(String.fromCharCode(charCode))) {
           return false;
       }
    };

现场演示

对于字母数字

看看这个

现场演示

Answer 2

在http://www.deadosaurus.com/detect-a-usb-barcode-scanner-with-javascript查看此内容

从链接中，我已修改为在不符合 10 个字符长度标准时自动清除文本，这可以假设不符合 10 个字符长度标准 = 不从条形码扫描仪输入。

我正在使用 ASP.NET，下面是我的示例：

对于 ASP 代码：

<asp:TextBox ID="TextBoxComponentPartNumber" runat="server" onkeypress="AutoClearOrSetInputText(event,this.id);" ></asp:TextBox>
        <asp:TextBox ID="TextBoxAssemblyPartNumber" runat="server" onkeypress="AutoClearOrSetInputText(event,this.id);" ></asp:TextBox>

对于 JavaScript：

<script type="text/javascript">

//This variables is for AutoClearOrSetInputText function
var pressed = false;
var chars = [];

//This function will auto clear or set input text box’s text value
function AutoClearOrSetInputText(eventForTextBox,idForTextBox) {

// add each entered char to the chars array
chars.push(String.fromCharCode(eventForTextBox.which));

// variable to ensure we wait to check the input we are receiving
if (pressed == false) {
// we set a timeout function that expires after 0.5 sec, once it does it clears out a list
// of characters
setTimeout(function() {
// check we have a long length e.g. it is a barcode
if (chars.length >= 10) {
// join the chars array to make a string of the barcode scanned
var barcode = chars.join(“”);
// assign value to input for barcode scanner scanned value
document.getElementById(idForTextBox).value = barcode;
}
else {
// clear value from input for non-barcode scanner scanned value
document.getElementById(idForTextBox).value = ”;
}
chars = [];
pressed = false;
}, 500);
}
// set press to true so we do not reenter the timeout function above
pressed = true;
}
</script>