Question

当我在某些设备上运行应用程序时，所以一切正常，但用户通常使用的其他设备，但随着时间的推移，应用程序退出并在每次打开后写入应用程序不幸停止工作。卸载并再次安装后，只能工作大约10分钟，然后再次出现相同的错误。当我报告错误发挥时，Google向我宣布了此消息。有谁知道该怎么办？抱歉英语不好。

java.lang.NullPointerException
at www.clientbook.cz.ClientBook.controlWebUrl(ClientBook.java:92)
at www.clientbook.cz.ClientBook.access$1(ClientBook.java:90)
at www.clientbook.cz.ClientBook$ClientBookClient.onPageFinished(ClientBook.java:239)
at android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:332)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:153)
at android.app.ActivityThread.main(ActivityThread.java:5297)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)

这是我的函数controlWebUrl()

private void controlWebUrl(String url) {
    //nastavení navigation
    if(!url.contains("/index/login") && !url.contains("/index/register") && !url.contains("/index/wait") && !url.contains("/index/active") && !url.contains("/index/forgotpassword")){
    mDrawerList.setAdapter(menuListLogin);
    login = true;
} else{
    mDrawerList.setAdapter(menuList);
    login = false;
}

if(url.contains("/index/login")){
    setTitle("Přihlášení");
} else if(url.contains("/index/register")){
    setTitle("Registrace");
} else if(url.contains("/index/forgotpassword")){
    setTitle("Zapomenuté heslo");
} else if(url.contains("/index/wait")){
    setTitle("Nepřišel vám e-mail ?");
} else if(url.contains("/index/profile")){
    setTitle("Můj profil");
} else if(url.contains("/clients/add")){
    setTitle("Přidat klienta");
} else if(url.contains("/clients/list")){
    setTitle("Seznam klientů");
} else if(url.contains("/clients/search")){
    setTitle("Hledat");
} else if(url.contains("/clients/map")){
    setTitle("Mapa klientů");
} else if(url.contains("/clients/show")){
    setTitle("Profil klienta");
} else if(url.contains("/clients/edit")){
    setTitle("Upravit klienta");
} else if(url.contains("/meetings")){
    setTitle("Schůzky");
} else if(url.contains("/forms")){
    setTitle("Dotazníky");
} else if(url.contains("/index/account")){
    setTitle("Můj účet");
} else if(url.contains("/index/settings")){
    setTitle("Nastavení");
} else if(url.contains("/index/search/type/sms")){
    setTitle("Hromadná SMS");
} else if(url.contains("/index/search/type/email")){
    setTitle("Hromadný E-mail");
} else if(url.contains("/index/search/type/dual")){
    setTitle("Hromadná SMS+E-mail");
} else if(url.contains("/index/search/type/history")){
    setTitle("Historie Hromadného rozesílání");
}  else {
    setTitle("ClientBook.cz");
}

}

问题出在哪里？功能必须有回报吗？

这是WebViewClient

private class ClientBookClient extends WebViewClient {

    @Override
    public boolean shouldOverrideUrlLoading(WebView webview, String url)
    {           
           if (!loadingFinished) {
               redirect = true;
            }

        loadingFinished = false;
        webview.loadUrl(url);
        return true;
    }

    @Override
    public void onPageStarted(WebView webview, String url, Bitmap favicon){
        loadingFinished = false;
    }


    @Override
    public void onPageFinished(WebView webview, String url) {
        controlWebUrl(mWebView.getUrl());
        if(!redirect){
            loadingFinished = true;
         }

         if(loadingFinished && !redirect && findViewById(R.id.connect).getVisibility() == View.GONE){
            findViewById(R.id.load_pb).setVisibility(View.GONE);
            findViewById(R.id.load_text).setVisibility(View.GONE);
            findViewById(R.id.connect).setVisibility(View.GONE);
            mWebView.setVisibility(View.VISIBLE);
         } else{
             if(findViewById(R.id.connect).getVisibility() == View.VISIBLE){
                 findViewById(R.id.load_pb).setVisibility(View.GONE);
             }
            redirect = false; 
            //error = false;
         }             


    }

    public void onReceivedError(WebView view, int errorCod,String description, String failingUrl) {
        if(errorCod == -1){
            mWebView.goBack();
        } else if(errorCod == -2){
            mWebView.setVisibility(View.GONE);
            TextView error_text = (TextView) findViewById(R.id.load_text);
            error_text.setText("Neumím pracovat bez internetu..");
            error_text.setVisibility(View.VISIBLE); 
            findViewById(R.id.connect).setVisibility(View.VISIBLE);

        }
    }       
}

Answer 1

在手机上，在菜单中启用Developer Options|Don't Save Activities，这样每次将Activity置于后台时都会被破坏。然后将您的应用程序放在ClientBook活动（或其他任何活动）的后台，然后恢复。您可能会遇到该异常，并且可以进行调试。

Answer 2

听起来问题是变量的生命周期。当你的应用程序处于睡眠状态时，操作系统会进入并释放一些内存。

您可以在onResume（）中执行一些空检查以帮助捕获它。基本上你想要检查你的应用程序是否已经被清除了＃39;虽然它睡着了。

您可以这样做：

protected void onResume(){      
    super.onResume();

    if(important_val == null){
        initialize_app();
        return;
    }
}

Answer 3

我在函数controlWebUrl（）

中添加了一个条件

private void controlWebUrl(String url) {
    if(url!=null){
    //nastavení navigation
    if(!url.contains("/index/login") && !url.contains("/index/register") && !url.contains("/index/wait") && !url.contains("/index/active") && !url.contains("/index/forgotpassword")){
        mDrawerList.setAdapter(menuListLogin);
        login = true;
    } else{
        mDrawerList.setAdapter(menuList);
        login = false;
    }

    if(url.contains("/index/login")){
        setTitle("Přihlášení");
    } else if(url.contains("/index/register")){
        setTitle("Registrace");
    } else if(url.contains("/index/forgotpassword")){
        setTitle("Zapomenuté heslo");
    } else if(url.contains("/index/wait")){
        setTitle("Nepřišel vám e-mail ?");
    } else if(url.contains("/index/profile")){
        setTitle("Můj profil");
    } else if(url.contains("/clients/add")){
        setTitle("Přidat klienta");
    } else if(url.contains("/clients/list")){
        setTitle("Seznam klientů");
    } else if(url.contains("/clients/search")){
        setTitle("Hledat");
    } else if(url.contains("/clients/map")){
        setTitle("Mapa klientů");
    } else if(url.contains("/clients/show")){
        setTitle("Profil klienta");
    } else if(url.contains("/clients/edit")){
        setTitle("Upravit klienta");
    } else if(url.contains("/meetings")){
        setTitle("Schůzky");
    } else if(url.contains("/forms")){
        setTitle("Dotazníky");
    } else if(url.contains("/index/account")){
        setTitle("Můj účet");
    } else if(url.contains("/index/settings")){
        setTitle("Nastavení");
    } else if(url.contains("/index/search/type/sms")){
        setTitle("Hromadná SMS");
    } else if(url.contains("/index/search/type/email")){
        setTitle("Hromadný E-mail");
    } else if(url.contains("/index/search/type/dual")){
        setTitle("Hromadná SMS+E-mail");
    } else if(url.contains("/index/search/type/history")){
        setTitle("Historie Hromadného rozesílání");
    }  else {
        setTitle("ClientBook.cz");
    }

    } else{
        return;
    }


}

然而它似乎正在发挥作用。但我不知道生命周期有什么问题，应用程序睡眠时有什么问题。所以，谢谢你的帮助：）

Android应用关机

3 个答案: