First of all, to judge the network state, you need to have the corresponding permission. The following is the permission code (AndroidManifest.xml) :

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

It then detects whether the network state is available

/**
 *  Determine the network connection status
 * @return  true,  Available;  false .   Do not use
 */ 
private boolean isOpenNetwork() { 
    ConnectivityManager connManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); 
    if(connManager.getActiveNetworkInfo() != null) { 
        return connManager.getActiveNetworkInfo().isAvailable(); 
    } 

    return false; 
} 

Finally, unavailability turns on network Settings

/**
 *  Visit baidu homepage, the network is not available then need to set
 */ 
private void initMoreGames() { 
    String URL_MOREGAMES = "http://www.baidu.com"; 
    mWebView = (WebView) findViewById(R.id.view_gamesort); 

    if (mWebView != null) { 
        mWebView.requestFocus(); 
        WebSettings webSettings = mWebView.getSettings(); 
        if (webSettings != null) { 
            webSettings.setJavaScriptEnabled(true); 
            webSettings.setCacheMode(MODE_PRIVATE); 
            webSettings.setDefaultTextEncodingName("utf-8"); 
        } 

        //  Determine if the network is available  
        if(isOpenNetwork() == true) { 
            mWebView.loadUrl(URL_MOREGAMES); 
        } else { 
            AlertDialog.Builder builder = new AlertDialog.Builder(MoreGamesActivity.this); 
            builder.setTitle(" No network is available ").setMessage(" Whether to set up the network ?"); 

            builder.setPositiveButton(" is ", new DialogInterface.OnClickListener() { 
                @Override 
                public void onClick(DialogInterface dialog, int which) { 
                    Intent intent = null; 

                    try { 
                        String sdkVersion = android.os.Build.VERSION.SDK; 
                        if(Integer.valueOf(sdkVersion) > 10) { 
                            intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS); 
                        }else { 
                            intent = new Intent(); 
                            ComponentName comp = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings"); 
                            intent.setComponent(comp); 
                            intent.setAction("android.intent.action.VIEW"); 
                        } 
                        MoreGamesActivity.this.startActivity(intent); 
                    } catch (Exception e) { 
                        Log.w(TAG, "open network settings failed, please check..."); 
                        e.printStackTrace(); 
                    } 
                } 
            }).setNegativeButton(" no ", new DialogInterface.OnClickListener() { 
                @Override 
                public void onClick(DialogInterface dialog, int which) { 
                    dialog.cancel();         
                    finish(); 
                } 
            }).show(); 
        } 
    } else { 
        Log.w(TAG, "mWebView is null, please check..."); 
    } 
}