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Understand the essence of iframe from beginning to end
- 王林Original
- 2024-01-07 09:33:48821browse
Understand the essence of iframe from beginning to end
Iframe (Inline Frame) is a tag in HTML that is used to embed another web page in a web page. It allows us to embed the content of other web pages into the current web page to achieve nested display of the page and expansion of functions. This article will gradually analyze the essence of Iframe from beginning to end and provide specific code examples.
The essence of Iframe is an independent HTML document, displayed in the form of a window in the current web page. Through the Iframe tag, we can embed other pages in a page to achieve page segmentation, function expansion and data interaction. The content in the Iframe is independent of the current web page. It has its own HTML code and CSS styles, and can be dynamically modified and manipulated through JavaScript.
The following is a sample code that shows how to use Iframe to embed another web page within the current web page.
<!DOCTYPE html>
<html>
<head>
<title>Iframe示例</title>
</head>
<body>
<h1>主页面</h1>
<iframe src="https://www.example.com" width="500" height="300"></iframe>
<p>这是主页面的内容。</p>
</body>
</html>In the above code, we have embedded the page with the URL https://www.example.com using the <iframe></iframe> tag. The page link to be displayed is specified through the src attribute, and the width and height of the Iframe are set through the width and height attributes. After the other content of the main page, we can see an embedded page displayed in the form of a window.
It should be noted that since the Iframe has an independent HTML document, the embedded page and the main page are independent of each other. Variables and functions cannot be shared directly between them and need to be communicated through other means.
You can use JavaScript to interact with embedded pages. Through the contentWindow property of Iframe, we can get the window object embedded in the page and then operate it using JavaScript. The sample code below shows how to pass data between the main page and the embedded page via a button click event.
<!DOCTYPE html>
<html>
<head>
<title>页面间数据传递</title>
</head>
<body>
<h1>主页面</h1>
<p>请输入内容：</p>
<input id="inputValue" type="text">
<button id="submitButton">提交</button>
<iframe id="myFrame" src="iframe.html" width="500" height="300"></iframe>
<script>
var iframe = document.getElementById("myFrame");
var inputValue = document.getElementById("inputValue");
var submitButton = document.getElementById("submitButton");
submitButton.addEventListener("click", function() {
var value = inputValue.value;
var iframeWindow = iframe.contentWindow;
iframeWindow.postMessage(value, "*");
});
</script>
</body>
</html>In the above code, we enter text content in the main page and pass the entered content to the embedded page when the submit button is clicked. Get the window object of the embedded page through the contentWindow property, and use the postMessage method to pass data to the embedded page.
In the embedded page, we can listen to the message event through the addEventListener method, receive the data passed from the main page, and perform corresponding operations. The following is a sample code embedded in the page:
<!DOCTYPE html>
<html>
<head>
<title>Iframe嵌入页面</title>
</head>
<body>
<h1>嵌入页面</h1>
<p id="output"></p>
<script>
window.addEventListener("message", function(event) {
var value = event.data;
var output = document.getElementById("output");
output.innerHTML = "接收到的数据：" + value;
});
</script>
</body>
</html>In the above code, we listen to the message event passed from the main page through the addEventListener method, and obtain the event object data attribute is the data passed from the main page. The data is then displayed on the page.
Through the above code examples, we can understand the essence of Iframe from beginning to end, and how to interact between the main page and the embedded page. Iframe has a wide range of application scenarios in web development and can help us implement complex functions and rich interactive experiences on the page. I hope this article will help you understand Iframe.
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