Web Front-end
JS Tutorial
JavaScript determines the file type uploaded by the FileUpload control_javascript skills
JavaScript determines the file type uploaded by the FileUpload control_javascript skills
In order to make the code simpler, the author uses regular expressions to obtain the file extension. If the reader does not know much about regular expressions or has never been exposed to them, please make up for it immediately! After all, it's so important that most programming languages support regular expressions.
As we all know, the method to obtain the FileUpload extension in the background:
string ext = Path.GetExtension(fu.PostedFile.FileName);
JS determines the extension of the file uploaded by the FileUpload control:
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>JS判断文件类型-乐猪网</title>
<script type="text/javascript">
function CheckFileUpload() {
var obj = document.getElementById('fu');
if (obj.value == "") {
alert("请选择要上传的文件！");
return false;
}
var stuff = obj.value.match(/^(.*)(\.)(.{1,8})$/)[3];
if (stuff != "zip") {
alert("文件类型不正确，请选择.zip文件！");
return false;
}
return true;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="fu" runat="server" />
<asp:Button ID="btnSave" runat="server" Text="保存"
OnClientClick="return CheckFileUpload();" />
</div>
</form>
</body>
</html>FileUpload instance rendering:
The above is how JS determines the extension of the file uploaded by the FileUpload control. I hope it will be helpful to everyone's learning.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1389
52
What should I do if I encounter garbled code printing for front-end thermal paper receipts?
Apr 04, 2025 pm 02:42 PM
Frequently Asked Questions and Solutions for Front-end Thermal Paper Ticket Printing In Front-end Development, Ticket Printing is a common requirement. However, many developers are implementing...
Who gets paid more Python or JavaScript?
Apr 04, 2025 am 12:09 AM
There is no absolute salary for Python and JavaScript developers, depending on skills and industry needs. 1. Python may be paid more in data science and machine learning. 2. JavaScript has great demand in front-end and full-stack development, and its salary is also considerable. 3. Influencing factors include experience, geographical location, company size and specific skills.
Demystifying JavaScript: What It Does and Why It Matters
Apr 09, 2025 am 12:07 AM
JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.
How to merge array elements with the same ID into one object using JavaScript?
Apr 04, 2025 pm 05:09 PM
How to merge array elements with the same ID into one object in JavaScript? When processing data, we often encounter the need to have the same ID...
The difference in console.log output result: Why are the two calls different?
Apr 04, 2025 pm 05:12 PM
In-depth discussion of the root causes of the difference in console.log output. This article will analyze the differences in the output results of console.log function in a piece of code and explain the reasons behind it. �...
How to achieve parallax scrolling and element animation effects, like Shiseido's official website?
or:
How can we achieve the animation effect accompanied by page scrolling like Shiseido's official website?
Apr 04, 2025 pm 05:36 PM
Discussion on the realization of parallax scrolling and element animation effects in this article will explore how to achieve similar to Shiseido official website (https://www.shiseido.co.jp/sb/wonderland/)...
Is JavaScript hard to learn?
Apr 03, 2025 am 12:20 AM
Learning JavaScript is not difficult, but it is challenging. 1) Understand basic concepts such as variables, data types, functions, etc. 2) Master asynchronous programming and implement it through event loops. 3) Use DOM operations and Promise to handle asynchronous requests. 4) Avoid common mistakes and use debugging techniques. 5) Optimize performance and follow best practices.
How to implement panel drag and drop adjustment function similar to VSCode in front-end development?
Apr 04, 2025 pm 02:06 PM
Explore the implementation of panel drag and drop adjustment function similar to VSCode in the front-end. In front-end development, how to implement VSCode similar to VSCode...
