This time I will show you how to interact with js in Android development. What are the precautions for interacting with js in Android development? The following is a practical case, let's take a look.
When we develop Android applications, we often need to deal with web pages. If we are making a takeaway app now, there will be a polling advertising space on the homepage of the app. When we click on one of them, it will jump. Go to a wap webpage. There may be promotional information for several restaurants on this webpage. After the user clicks on a restaurant, we hope that the wap page will pop up to display the details of the restaurant. At this time, we need to use js to call java code to achieve this. . Or, if we need to share in a wap page, we may also need to use js to call java code to perform the sharing operation. There are many scenarios like this. If we need to implement this function, we must understand the interaction method between java and js. Use of WebViewIf we want to display a web page in Android, we will basically use the WebView component. Its<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<WebView
android:id="@+id/web_view"
android:layout_width="match_parent"
android:layout_height="match_parent" /></RelativeLayout> and then use it in the java file WebView webView = (WebView) findViewById(R.id.web_view);
webView.loadUrl("http://www.baidu.com"); At the same time, WebView also allows us to modify some default settings. Modification, for example, if we want to enable support for javascript and be able to zoom, we need to make the following settings:
// 启用javascriptwebView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setUseWideViewPort(true);//是否可以缩放webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getSettings().setDisplayZoomControls(false);
} However, if we want to handle various notifications when the page loads , request events, or monitor the loading progress of the page, etc., you need to use two other classes: WebViewClient and WebChromeClient. Among them, WebViewClient is mainly used to listen for notifications or request events. The methods we may use in development are mainly the following: onPageStartedonPageFinishedonReceivedErrorshouldOverrideUrlLoadingThe WebChromeClient is used to handle javascript, website icons, website titles, loading progress, etc. When we use WeChat, if we open a webpage, we will see a green stripe on it. Progress bar, this function is achieved by overriding the onProgressChanged method of WebChromeClient:
public class CustomWebClient extends WebChromeClient {
@Override public void onProgressChanged(WebView view, int newProgress) {
if (newProgress == 100) {
mProgressBar.setVisibility(GONE);
} else {
if (mProgressBar.getVisibility() == GONE) {
mProgressBar.setVisibility(VISIBLE);
}
mProgressBar.setProgress(newProgress);
}
super.onProgressChanged(view, newProgress);
}
} In addition, WebView also provides the function of running javascript directly. For example, we can A simple dialog box pops up: webView.loadUrl("javascript:alert(\"提示信息！\");");Of course, if we want to execute js, then two conditions must be met. The first is to enable javascript support in the settings, that is, setJavascriptEnabled(true) needs to be called. The second is to set up WebChromeClient, both of which are indispensable. I believe you have mastered the methods after reading these cases. For more exciting information, please pay attention to other related articles on the php Chinese website! Related reading:
Basic JavaScript Data Types
How to Remember Account and Password in JS Code
The above is the detailed content of How to interact with js in Android development. For more information, please follow other related articles on the PHP Chinese website!
Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AMPython is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AMPython and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AMThe shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.
JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AMDifferent JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.
Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AMJavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.
Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AMI built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing
How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AMThis article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base
JavaScript: Exploring the Versatility of a Web LanguageApr 11, 2025 am 12:01 AMJavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.
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
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
SublimeText3 Chinese version
Chinese version, very easy to use
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
Zend Studio 13.0.1
Powerful PHP integrated development environment
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
Atom editor mac version download
The most popular open source editor
