Question

我正在研究Android应用程序，它主要在互联网上运行。现在问题是当我使用我的应用程序时，由于互联网应用程序崩溃了。事情是在打开妻子之后，我编写了使用连接管理器类来获取网络状态的代码，它给网络带来了好处并且返回了真值，但实际上通过网络的数据没有处理（这意味着没有互联网访问）。那么，当网络状态为真且网络访问为假（无法访问Internet）时，如何防止应用程序崩溃消息。

Answer 1

在从您的应用使用互联网之前，尝试检查设备是否已连接

    ConnectivityManager con=(ConnectivityManager)getSystemService(Activity.CONNECTIVITY_SERVICE);
    boolean wifi=con.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();
    boolean internet=con.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting();
    //check Internet connection
    if(internet||wifi)
    {
        //your code
    }else{
        new AlertDialog.Builder(this)
        .setIcon(R.drawable.title)
        .setTitle("No internet connection")
        .setMessage("Please turn on mobile data")
        .setPositiveButton("OK", new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //code for exit
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.addCategory(Intent.CATEGORY_HOME);            
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(intent);
            }

        })
        .show();
    }

不要忘记添加所需的权限

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

Answer 2

试试这段代码：

 //Check if Internet Network is active
 private boolean checkNetwork() {
 boolean wifiDataAvailable = false;
 boolean mobileDataAvailable = false;
ConnectivityManager conManager = (ConnectivityManager)     
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo[] networkInfo = conManager.getAllNetworkInfo();
for (NetworkInfo netInfo : networkInfo) {
 if (netInfo.getTypeName().equalsIgnoreCase("WIFI"))
  if (netInfo.isConnected())
     wifiDataAvailable = true;
       if (netInfo.getTypeName().equalsIgnoreCase("MOBILE"))
       if (netInfo.isConnected())
         mobileDataAvailable = true;
}
   return wifiDataAvailable || mobileDataAvailable;
}

将代码放在try catch块中以查看异常。

来源：http://code2care.org/pages/how-to-check-internet-connection-wifi-3g-4g-is-active-on-android-programatically/

Answer 3

制作一个班级ConnectionDetector

public class ConnectionDetector {

private Context _context;

public ConnectionDetector(Context context) {
    this._context = context;
}


public boolean isConnectingToInternet() {
    ConnectivityManager connectivity = (ConnectivityManager) _context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity != null) {

        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;
}
   }

现在在您的Activity中将onCreate（）方法称为

 ConnectionDetector cd = new ConnectionDetector(this);

 if(cd.isConnectingToInternet) {

   // do your stuff here

 } else {
   // No Internet Connection
 }

Answer 4

   //define global variable   

    public static boolean isHaveInternet = true;

    //add permission in androidmainfest file
    <receiver android:name="NetworkReciver" >
        <intent-filter>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
        </intent-filter>
    </receiver>


    //add class for networkcheck

    package com.example;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.util.Log;

     public class NetworkReciver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent arg1) {

    boolean status = GeneralClass.getConnectivityStatusString(context);

    GeneralClass.isHaveInternet = status ? true : false;
    if (status)

        Log.e("NET-------------->", "connecte" + status);

    else
        Log.e("NET------------->", "not connecte" + status);
}
}

    //check network connection where  you want

    if (GeneralClass.isHaveInternet) 
    {
                    //your code

    } 
    else
    {
                    Toast.makeText(getApplicationContext(),
                            "Internet connection not avilable",
                            Toast.LENGTH_SHORT).show();
    }

如何在与网络连接时停止崩溃Android应用程序？

4 个答案: