如何使用onpause和onresume创建浏览url的活动

Question

你能帮我一下吗?

如果互联网连接可用，如何创建一个在oncreate方法运行url的活动?

我想检查互联网连接是否可用，每5秒，如果互联网连接消失，它会警告为对话框只有一次。

如果Internet连接到来，那么活动将在会话关闭的地方恢复

我的代码下面是:

    public class MainActivity extends Activity {
private String URL="http://www.moneycontrol.com/";
private Handler mHandler = new Handler();
private boolean isRunning = true;
private TextView textlabel=null;    
public WebView webview=null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textlabel=(TextView)findViewById(R.id.textlabel);
        displayData();
    }
    private void Chekstate() {
    new Thread(new Runnable() {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            while (isRunning) {
                try {
                    Thread.sleep(1000);
                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            // TODO Auto-generated method stub
                            // Write your code here to update the UI.
                            displayData();
                        }
                    });
                } catch (Exception e) {
                    // TODO: handle exception
                }
            }
        }
    }).start(); 
    }

    @SuppressWarnings("deprecation")
    private void displayData() {
        ConnectivityManager cn=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo nf=cn.getActiveNetworkInfo();
        if(nf != null && nf.isConnected()==true )
        {
           textlabel.setText("Network Available");
           Webview();
        }
        else
        {
           textlabel.setText("Network Not Available");
           final AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
           alertDialog.setTitle("Intenet Connecction");
           alertDialog.setMessage("Internet Connetion is not available now.");
           alertDialog.setButton(" OK ", new OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                alertDialog.dismiss();
            }
        });
           alertDialog.show();
        }       
    } 

      @Override
        protected void onResume() {
            super.onResume();
        }
        @Override
        protected void onPause() {
            super.onPause();
        }
    @SuppressLint("SetJavaScriptEnabled")
    private void Webview() {
        webview= (WebView) findViewById(R.id.webview);
        webview.getSettings().setJavaScriptEnabled(true);
        webview.setWebViewClient(new WebViewClient());
        webview.loadUrl(URL);
        webview.setInitialScale(1);
        webview.getSettings().setBuiltInZoomControls(true);
        webview.getSettings().setUseWideViewPort(true);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

Answer 1

要检查网络连接，您可以使用以下命令。

在清单

中添加以下权限

 <uses-permission android:name="android.permission.INTERNET"/>
 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

使用处理程序

Handler mHandler = new Handler();
boolean isRunning = true;

然后，从你的onCreate()方法中使用这个线程:

new Thread(new Runnable() {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            while (isRunning) {
                try {
                    Thread.sleep(5000);
                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            // TODO Auto-generated method stub
                            // Write your code here to update the UI.
                            displayData();
                        }
                    });
                } catch (Exception e) {
                    // TODO: handle exception
                }
            }
        }
    }).start(); 

然后，声明这个由你的处理器每5秒调用一次的方法:

    private void displayData() {
    ConnectivityManager cn=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo nf=cn.getActiveNetworkInfo();
    if(nf != null && nf.isConnected()==true )
    {
        Toast.makeText(this, "Network Available", Toast.LENGTH_SHORT).show();
        myTextView.setText("Network Available");
    }
    else
    {
        Toast.makeText(this, "Network Not Available", Toast.LENGTH_SHORT).show();
        myTextView.setText("Network Not Available");
    }       
} 

停止线程调用:

   isRunning = false;

或者，您可以使用下面的命令。但是它不会每5秒检查一次连接

public class CheckNetwork {
private static final String TAG = CheckNetwork.class.getSimpleName();
public static boolean isInternetAvailable(Context context)
{
NetworkInfo info = (NetworkInfo) ((ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
if (info == null)
{
     Log.d(TAG,"no internet connection");
     return false;
}
else
{
    if(info.isConnected())
    {
        Log.d(TAG," internet connection available...");
        return true;
    }
    else
    {
        Log.d(TAG," internet connection");
        return true;
    }
   }
 }
}

在onCreate()

if(CheckNetwork.isInternetAvailable(MainActivtiy.this))  //if connection available
{
}

http://developer.android.com/training/monitoring-device-state/connectivity-monitoring.html

您可以使用广播接收器。当连通性丢失时，系统会广播。但我建议不要使用广播接收器。