Question

我在我的Android应用程序中从服务器获取数据，同时检查Internet连接，当没有Internet连接时应用程序崩溃。我使用默认的http连接来连接服务器。

检查互联网连接的代码是：

public void onClick(View view) {
    ConnectivityManager cm = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnectedOrConnecting()) {
        //if it is connected to internet than start Another Activity.
        startActivity(new Intent(SearchActivity.this, SearchActivity.class));
    } else if (netInfo == null) {
        AlertDialog alertDialog = new AlertDialog.Builder(ListViewExample.this).create();
        alertDialog.setTitle("Connection Problem");
        alertDialog.setMessage("You are not connected to Internet");
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface dialog, int which) {
                return;
            }
        });
        alertDialog.show();
    }

}

Answer 1

确保您已在清单文件中添加此权限，

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

Answer 2

使用此代码检查互联网连接，检查设备上的所有互联网连接。并且确保你已经在menifest中添加了Internet权限。

        boolean flag=false;
        ConnectivityManager connectivity = (ConnectivityManager) getApplicationContext().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)
                    {
                        flag=true;

                    }

        }
        if(flag==true)
        {
             startActivity(new Intent(SearchActivity.this, SearchActivity.class));
        }
        else
        {
             AlertDialog alertDialog = new AlertDialog.Builder(ListViewExample.this).create();
        alertDialog.setTitle("Connection Problem");
        alertDialog.setMessage("You are not connected to Internet");
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface dialog, int which) {
                return;
            }
        });
        alertDialog.show();
        }

无法检查互联网连接（Android）？

2 个答案: