App inventor:aix檔練習3，取得網路資料。

 import android.app.Activity;

import android.content.Context;

import com.google.appinventor.components.annotations.*;

import com.google.appinventor.components.common.ComponentCategory;

import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;

import com.google.appinventor.components.runtime.ComponentContainer;

import com.google.appinventor.components.runtime.EventDispatcher;

import com.google.appinventor.components.runtime.AndroidViewComponent;

import android.view.View;

import android.graphics.Bitmap;

import java.io.FileOutputStream;

import android.graphics.Bitmap.CompressFormat;

import android.content.pm.PackageManager;

import java.net.CookieHandler;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.ProtocolException;

import java.net.SocketTimeoutException;

import java.net.URISyntaxException;

import java.net.URL;

import java.net.URLDecoder;

import java.net.URLEncoder;

import android.os.Environment;

import java.io.File;

import com.google.appinventor.components.runtime.util.AsynchUtil;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.URL;

import java.net.HttpURLConnection;

import java.net.URLConnection;

@DesignerComponent(

version = 1,

description = "",

category = ComponentCategory.EXTENSION,

nonVisible = true,

iconName = "")

@SimpleObject(external = true)

//Libraries

@UsesLibraries(libraries = "")

//Permissions

@UsesPermissions(permissionNames = "android.permission.INTERNET"+"android.permission.ACCESS_NETWORK_STATE")

public class TA extends AndroidNonvisibleComponent {

//Activity and Context

private Context context;

private Activity activity;

public TA(ComponentContainer container){

super(container.$form());

this.activity = container.$context();

this.context = container.$context();

}

@SimpleFunction(description = "Sample Function Generated by Niotron")

public void WebsiteContent(final String website) {

AsynchUtil.runAsynchronously(new Runnable() { // Always do get request Asynchronously

@Override

public void run() {

try {

URL url = new URL(website);

URLConnection urlConnection = url.openConnection();

HttpURLConnection connection = null;

if(urlConnection instanceof HttpURLConnection)

{

connection = (HttpURLConnection) urlConnection;

}

else

{

}

BufferedReader readStream = new BufferedReader(

new InputStreamReader(connection.getInputStream()));

// BufferedReader的作用在於用串流的方式讀取資料的，URL()可連接網頁.openStream是它的一種連接方法

String readLine; // 宣告讀取的變數資料名為readLine

StringBuilder data = new StringBuilder(); // 這結果的資將建立於此

//當資料不為空的時間，就將新的資料readLine存到 data這個變數的最後

while (( readLine = readStream.readLine() ) != null)

data.append(readLine); // Read all the lines from the readStream

readStream.close(); //關掉這個readStream

final String finalData = data.toString(); // 將findaData轉為String型態

activity.runOnUiThread(new Runnable() { // Always raise events on UI thread

@Override

public void run() {

//取得資料後，傳到Event中執行

myEvent(finalData); // You're event with data

}

});

} catch (IOException e) {

e.printStackTrace(); // Error occured

}

}

});

}

@SimpleEvent(description = "Test Event Generated by Niotron")

public void myEvent(String Data){

EventDispatcher.dispatchEvent(this, "myEvent",Data);

}

}

參考網頁：https://juejin.cn/post/6844903970649931783