Android 检查数据连接

我有一个按钮，带有打开另一个类的onclick事件。另一个类正在进行网络调用以检索数据，因此如果没有连接，则应用程序强制关闭

如何实现可以检查数据连接的try-catch或if语句，如果没有，则显示这样的toast语句。如果有，则进入二等舱。

我使用：

public boolean isOnline() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnectedOrConnecting()) {
        return true;
    }
    return false;
}

---

执行以下操作以检查internet连接：

static public boolean isInternetActive() 
{
    ConnectivityManager connectivity = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo info = (NetworkInfo) connectivity.getActiveNetworkInfo();

    if (info == null || !info.isConnected()) 
    {
        return false;
    }
    if (info.isRoaming()) 
    {
        return false;
    }
    return true;
}

您还需要：

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

---

在android清单中。

此代码检查是否打开或关闭了internet连接。此代码检查wifi和电话网络

public boolean CheckInternet() 
{
    ConnectivityManager connec = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
 android.net.NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

    android.net.NetworkInfo mobile = connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

    // Here if condition check for wifi and mobile network is available or not.
    // If anyone of them is available or connected then it will return true, otherwise false;

    if (wifi.isConnected()) {
        return true;
    } else if (mobile.isConnected()) {
        return true;
    }
    return false;
}

清单文件：：

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

---

试试这个，这会对你有所帮助

public class CheckNetworkInfo {

    public static boolean haveNetworkConnection(Context context) {

         ConnectivityManager cm = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);
            // test for connection
            if (cm.getActiveNetworkInfo() != null
                    && cm.getActiveNetworkInfo().isAvailable()
                    && cm.getActiveNetworkInfo().isConnected()) {
                Log.v("Yeah", "Internet is working");
                // txt_status.setText("Internet is working");
                return true;
            } else {
                // txt_status.setText("Internet Connection Not Present");
                Log.v("Sorry", "Internet Connection Not Present");
                return false;
            }
}

//在需要检查网络可用性的地方，调用上述类静态方法

class Myactivity extends Activity{

public void onCreate(Bundle savedInstanceState) {

    if(CheckNetworkInfo.haveNetworkConnection(Myactivity.this)){
            startActivity(new Intent(HomePage.this,SearchTerm.class));
        }
        else{
            AlertDialog.Builder a=new AlertDialog.Builder(Myactivity.this);
            a.setTitle("Check Network Connection");
            a.setPositiveButton("OK",new android.content.DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                dialog.dismiss();   
                }
            });
            a.show();
        }
}
}

简单地使用它

从任何地方调用此代码，它将返回网络的当前状态

public static boolean isInternetAvailable(Context c)
    {
         ConnectivityManager connectivityManager 
         = (ConnectivityManager) c.getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
         return activeNetworkInfo != null && activeNetworkInfo.getState() == NetworkInfo.State.CONNECTED;
    }

如果已连接，则返回true，否则返回false。对其输出执行任何所需的操作

注：这是一种静态方法。所以，如果您只想在Android活动类中调用static关键字，请删除它

public static boolean isInternetAvailable(Context c)
    {
         ConnectivityManager connectivityManager 
         = (ConnectivityManager) c.getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
         return activeNetworkInfo != null && activeNetworkInfo.getState() == NetworkInfo.State.CONNECTED;
    }