检查Android中的internet连接,如果活动不可用,请重新加载该活动
我开发了一个Android RSS阅读器。我创建了一个选项卡布局,并为每种类型的新闻创建了每个选项卡(如标题、国家、国际等) 然后我在tablayout的第一页的CustomListView中列出了RSS标题及其图像。 见下图 现在,当用户单击新闻标题时,另一个活动(页面)将打开,其中包含新闻描述 我的问题是,当用户单击选项卡并加载时,如果internet连接不可用,我想显示一个带有两个按钮的对话框,请重试并退出 当用户单击“重试”时,应该重新加载活动。我使用了一种方法(if(International.Title==null))。但我认为这不是一种正确的方法。我想知道是否有更好的解决方案来检查网络是否可用 这是我的密码检查Android中的internet连接,如果活动不可用,请重新加载该活动,android,android-networking,Android,Android Networking,我开发了一个Android RSS阅读器。我创建了一个选项卡布局,并为每种类型的新闻创建了每个选项卡(如标题、国家、国际等) 然后我在tablayout的第一页的CustomListView中列出了RSS标题及其图像。 见下图 现在,当用户单击新闻标题时,另一个活动(页面)将打开,其中包含新闻描述 我的问题是,当用户单击选项卡并加载时,如果internet连接不可用,我想显示一个带有两个按钮的对话框,请重试并退出 当用户单击“重试”时,应该重新加载活动。我使用了一种方法(if(Internat
public class International extends Activity {
static final String URL = "http://www.abcd.com/en/taxonomy/term/3/0/feed";
static final String KEY_HEAD = "item";
static final String KEY_DATE = "pubDate";
ListView list;
InternationalAdapter adapter;
public static String[] Title;
public static String[] Description;
public static String[] image;
public static String[] Date;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.headlines);
Bundle mybundle = new Bundle();
mybundle.putString("number", "0");
new DoInBackground().execute();
}
public void do_update()
{
internationalparser.parse();//this is the function to parse RSS feeds
}
public void populate_listview()
{
ArrayList<HashMap<String, String>> newsList = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML from URL
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_HEAD);
// looping through all song nodes <song>
NodeList itemLst = doc.getElementsByTagName("item");
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
//map.put(KEY_DATE, parser.getValue(e, KEY_DATE));
newsList.add(map);
}
list=(ListView)findViewById(R.id.list);
// Getting adapter by passing xml data ArrayList
adapter=new InternationalAdapter(this, newsList);
list.setAdapter(adapter);
// Click event for single list row
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Intent myintent = new Intent("com.abcd.rssreaderinternationalpodcast.PODCAST");
Bundle mybundle = new Bundle();
mybundle.putInt("number", position);
myintent.putExtras(mybundle);
startActivity(myintent);
}
});
}
private class DoInBackground extends AsyncTask<Void, Void, Void>
implements DialogInterface.OnCancelListener
{
private ProgressDialog dialog;
private Intent intent;
private Intent intent2;
public void onPreExecute()
{
dialog = ProgressDialog.show(International.this, "", "Loading", true);
}
protected Void doInBackground(Void... unused)
{
do_update();
return null;
}
public void retry()
{
internationalparser.parse();
}
protected void onPostExecute(Void unused)
{
if(International.Title!=null)
{
dialog.dismiss();
populate_listview();
}
if(International.Title==null) ///this is what I tried.
{
dialog.dismiss();
AlertDialog.Builder alertbox = new AlertDialog.Builder(International.this);
alertbox.setMessage("Error in connection!");
alertbox.setPositiveButton("Retry", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
retry(); //here i want to reload activity
}
});
alertbox.setNegativeButton("Exit", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
finish();
}
});
alertbox.show();
}
}
public void onCancel(DialogInterface dialog)
{
cancel(true);
dialog.dismiss();
}
}
}
公共类国际扩展活动{
静态最终字符串URL=”http://www.abcd.com/en/taxonomy/term/3/0/feed";
静态最终字符串键\u HEAD=“item”;
静态最终字符串键\u DATE=“pubDate”;
列表视图列表;
国际适配器;
公共静态字符串[]标题;
公共静态字符串[]说明;
公共静态字符串[]图像;
公共静态字符串[]日期;
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.headlines);
Bundle mybundle=新Bundle();
mybundle.putString(“数字”、“0”);
新建DoInBackground().execute();
}
public void do_update()
{
internationalparser.parse();//这是解析RSS源的函数
}
public void populate_listview()
{
ArrayList newsList=新建ArrayList();
XMLParser=新的XMLParser();
字符串xml=parser.getXmlFromUrl(URL);//从URL获取xml
Document doc=parser.getDomeElement(xml);//获取DOM元素
NodeList nl=doc.getElementsByTagName(键头);
//循环通过所有歌曲节点
nodelistitemlst=doc.getElementsByTagName(“项”);
对于(int i=0;i
更新::
new DoInBackground().execute();
按如下所示替换此行,然后重试
if(isNetworkAvailable(YourActivity.this))
new DoInBackground().execute();
else{
makeAndShowDialogBox();
}
更新::
new DoInBackground().execute();
按如下所示替换此行,然后重试
if(isNetworkAvailable(YourActivity.this))
new DoInBackground().execute();
else{
makeAndShowDialogBox();
}
这是我使用重试/退出进行internet连接的类 用法:
URLContent httpContent = new URLContent(this);
String test = httpContent.getContent("http://www.hotmail.com/");
类别:
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
public class URLContent {
MainActivity mMainActivity;
String returnData;
String address;
public URLContent(MainActivity mMainActivity)
{
this.mMainActivity = mMainActivity;
}
public String getContent(String address)
{
this.address = address;
processContent(address);
return returnData;
}
private void processContent(String address)
{
try {
if (!isNetworkAvailable(mMainActivity))
{
throw new Exception("No internet connectivity.");
}
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(address));
HttpResponse response = client.execute(request);
if (response.getStatusLine().getStatusCode() == 200)
{
InputStream ips = response.getEntity().getContent();
BufferedReader buf = new BufferedReader(new InputStreamReader(ips,"UTF-8"));
StringBuilder sb = new StringBuilder();
String s;
while(true)
{
s = buf.readLine();
if(s==null || s.length()==0)
break;
sb.append(s);
}
buf.close();
ips.close();
returnData = sb.toString();
}
else
{
throw new Exception();
}
} catch (Exception e) {
makeAndShowDialogBox(e.getMessage()).show();
}
}
private static boolean isNetworkAvailable(Context context)
{
ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity == null)
{
return false;
} else
{
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
{
for (int i = 0; i < info.length; i++)
{
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
}
}
return false;
}
private AlertDialog makeAndShowDialogBox(String msg)
{
AlertDialog myQuittingDialogBox = new AlertDialog.Builder(mMainActivity)
.setCancelable(false)
.setTitle(R.string.connectionerr)
.setMessage(msg)
.setPositiveButton("Retry", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
//whatever should be done when answering "YES" goes here
getContent(address);
}
})//setPositiveButton
.setNegativeButton("Exit", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
//whatever should be done when answering "NO" goes here
mMainActivity.finish();
}
})//setNegativeButton
.create();
return myQuittingDialogBox;
}
}
导入java.io.BufferedReader;
导入java.io.InputStream;
导入java.io.InputStreamReader;
导入java.net.URI;
导入org.apache.http.HttpResponse;
导入org.apache.http.client.HttpClient;
导入org.apache.http.client.methods.HttpGet;
导入org.apache.http.impl.client.DefaultHttpClient;
导入android.app.AlertDialog;
导入android.content.Context;
导入android.content.DialogInterface;
导入android.net.ConnectivityManager;
导入android.net.NetworkInfo;
公共类URL内容{
主要活动和不活动;
字符串返回数据;
字符串地址;
公共URL内容(主活动和非活动)
{
this.mMainActivity=mMainActivity;
}
公共字符串getContent(字符串地址)
{
this.address=地址;
处理内容(地址);
返回数据;
}
私有void processContent(字符串地址)
{
试一试{
如果(!isNetworkAvailable(不活动))
{
抛出新异常(“无internet连接”);
}
HttpClient=new DefaultHttpClient();
HttpGet请求=新建HttpGet();
请求.setURI(ne)