


10_Access the network through HttpUrlConnection in Android, use Handler and multi-threading, read network html code and display it on the interface, use of ScrollView component_html/css_WEB-ITnose
??
编写如下项目:
2 编写Android清单文件
|
3 编写布局文件activity_main.xml
|
4 编写Activity的类MainActivity如下:
package com.itheima28.htmldemo;
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL;
import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.text.TextUtils; import android.util.Log; import android.view.View; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast;
public class MainActivity extends Activity {
private static final String TAG = "MainActivity"; private static final int SUCCESS = 0; protected static final int ERROR = 1; private EditText etUrl; private TextView tvHtml;
private Handler handler = new Handler() {
@Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case SUCCESS: tvHtml.setText((String) msg.obj); break; case ERROR: Toast.makeText(MainActivity.this, "访问失败", 0).show(); break; default: break; } }
};
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
etUrl = (EditText) findViewById(R.id.et_url); tvHtml = (TextView) findViewById(R.id.tv_html);
}
public void getHtml(View v) { final String url = etUrl.getText().toString();
new Thread(new Runnable() {
@Override public void run() { // 请求网络 String html = getHtmlFromInternet(url);
if(!TextUtils.isEmpty(html)) { // 更新textview的显示了 Message msg = new Message(); msg.what = SUCCESS; msg.obj = html; handler.sendMessage(msg); } else { Message msg = new Message(); msg.what = ERROR; handler.sendMessage(msg); } } }).start(); }
/** * Access the network based on the given url and grab the html code * @param url * @return */ protected String getHtmlFromInternet(String url) {
try { URL mURL = new URL(url); HttpURLConnection conn = (HttpURLConnection) mURL.openConnection();
conn.setRequestMethod("GET"); conn.setConnectTimeout(10000); conn.setReadTimeout(5000);
// conn.connect();
int responseCode = conn.getResponseCode();
if(responseCode == 200) { InputStream is = conn.getInputStream(); String html = getStringFromInputStream(is); return html; } else { Log.i(TAG, "访问失败: " responseCode); } } catch (Exception e) { e.printStackTrace(); } return null; }
/** * Return a string information according to the stream * @param is * @return * @throws IOException */ private String getStringFromInputStream(InputStream is) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len = -1;
} is.close(); : utf-8 .contains("gb2312") || html.contains("GBK") || html.contains("GB2312")) { // If it contains gbk, gb2312 encoding, use gbk encoding for comparison String encoding charset = "gbk"; } html newString(baos.toByteArray() , charset); // Encode the encoding name after using the original byte array baos.close(); returnhtml; } }
Copyright statement: This article is an original article by the blogger and has not been authorized by the blogger. No reproduction allowed with permission of the owner.
|

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











The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTML, CSS and JavaScript are the core technologies for building modern web pages: 1. HTML defines the web page structure, 2. CSS is responsible for the appearance of the web page, 3. JavaScript provides web page dynamics and interactivity, and they work together to create a website with a good user experience.

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

The article discusses the differences between HTML tags , , , and , focusing on their semantic vs. presentational uses and their impact on SEO and accessibility.
