Question

所以我有一个基于webview的应用程序。我的问题是，当网络丢失时调用OnReceivedError时，我想

当用户在对话框中单击“确定”以检查连接时，

如果连接可用，请关闭提醒并致电web.reload();
如果没有网络连接（wifi或移动设备），请拨打finish();

由以下决议解决：

将警报对话框更改按钮更改为以下

.setPositiveButton(R.string.alert_dialog_ok,new DialogInterface.OnClickListener() {         
 public void onClick(DialogInterface dialog,int id) {

问题在于以下

DialogInterface paramDialogInterface,int paramInt)

上下文上下文;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  this.context = this;
  ...
  @Override
public void onReceivedError(WebView view, int errorCode,
            String description, String failingUrl) {
        AlertDialog.Builder localBuilder2 = new AlertDialog.Builder(
                Webview_Main.this);
        localBuilder2.setTitle(R.string.webview_error_received_title);
        localBuilder2.setMessage(R.string.webview_error_received);
        localBuilder2.setIcon(R.drawable.ic_launcher);
        localBuilder2.setPositiveButton(R.string.alert_dialog_ok,new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                 if(isNetworkAvailible(context))
                 web.reload();
                 else
                 finish();
         }
    };
        localBuilder2.show();
    };

isNetworkAvailible Class

   public boolean isNetworkAvailible(Context ctx) {

    NetworkInfo info = (NetworkInfo) ((ConnectivityManager) ctx
            .getSystemService(Context.CONNECTIVITY_SERVICE))
            .getActiveNetworkInfo();

    if (info == null || !info.isConnected()) {
        return false;
    }
    if (info.isRoaming()) {
        // here is the roaming option you can change it if you want to
        // disable internet while roaming, just return false
        return false;
    }
    return true;
}

Answer 1

由于代码中的此关键字引用了DialogInterface.OnClickListener，因此没有为该类型定义getSystemService，因此必须从引用当前内容的上下文变量调用getSystemService活动，例如，像这样：

context.getSystemService(Activity.CONNECTIVITY_SERVICE)

Answer 2

纠正我的回答：

    Context context;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
            this.context = this; 
    }


@Override
public void onReceivedError(WebView view, int errorCode,
            String description, String failingUrl) {
        AlertDialog.Builder localBuilder2 = new AlertDialog.Builder(
                Webview_Main.this);
        localBuilder2.setTitle(R.string.webview_error_received_title);
        localBuilder2.setMessage(R.string.webview_error_received);
        localBuilder2.setIcon(R.drawable.ic_launcher);
        localBuilder2.setPositiveButton(R.string.alert_dialog_ok,
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface paramDialogInterface,int paramInt) {
                    if(haveInternet(context))
                        web.reload();
                    else
                        finish();
                }
            });
        localBuilder2.show();
    };

public boolean haveInternet(Context ctx) {

    NetworkInfo info = (NetworkInfo) ((ConnectivityManager) ctx
            .getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();

    if (info == null || !info.isConnected()) {
        return false;
    }
    if (info.isRoaming()) {
        // here is the roaming option you can change it if you want to
        // disable internet while roaming, just return false
        return false;
    }
    return true;
}

Answer 3

我可能会错过很多时间，但似乎你正在创建一个DialogInterface.OnClickListener，但没有指定它来处理任何事情。

更改您的代码：

    localBuilder2.setPositiveButton(R.string.alert_dialog_ok, null);

    localBuilder2.setOnClickListener(new DialogInterface.OnClickListener() {
        ...
    });

Answer 4

检查网络可用性

在你的Activtiy中

if(CheckNetwork.isInternetAvailable(ActvityName.this))// pass activity context
     {
             //do soemthing
     }

如果需要检查非活动类中的网络可用性，则需要将活动上下文作为参数传递给类构造函数并使用活动上下文。

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);
    MyAnotherClass = new MyAnotherClass(MainActivtity.this); 

}

在你的MyAnotherClass

中

    Class MyAnotherClass
      {
          Context context;
         public MyAnotherClass(Context activitycontext)
         {
             this.context= activitycontext;
             if(CheckNetwork.isInternetAvailable(context))
             {
                     //do something
             }
         }
      }

CheckNetwork类

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;
        }

    }
}
}

在解除警报对话框之前检查网络连接

4 个答案: