Question

我正在尝试在Android项目中进行登录验证。我想将cookie从活动传递给activity.To传递cookie，我创建了一个应用程序类。这是应用程序类;

public class TestApplication extends Application{

    public Cookie tempClass;

    public TestApplication () {
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate() { 
        // TODO Auto-generated method stub
        super.onCreate();
    }

    public Cookie getTempClass() {
        return tempClass;
    }

    public void setTempClass(Cookie tempClass) {
        this.tempClass  = tempClass;
    }

}

我试图在这里的活动中使用;

public void run() {
                        // TODO Auto-generated method stub          
                        //String sessionId="";
                        Cookie userCookie=null;
                        List<Cookie> cookies = ((AbstractHttpClient) httpClient).getCookieStore().getCookies();
                         if (cookies.isEmpty()) {
                                System.out.println("None");
                            } else {
                                for (int i = 0; i < cookies.size(); i++) {
                                    //System.out.println("-Cokkkiiieee " + cookies.get(i).toString());
                                    userCookie =cookies.get(i);
                                }
                                testAppObj = (TestApplication)getApplication();
                                testAppObj.setTempClass(userCookie);
                                Intent menu = new Intent("android.intent.action.MENU");
                                startActivity(menu);
                            }
                    }


             };
                (new Thread(runnable)).start();

显示LogCat：

 FATAL EXCEPTİON : Thread-9
 java.lang.ClassCastException : android.app.Application
 at com.example.example.MainActivity$2.run(MainActivity.java:176)
 at java.lang.Thread.Run(Thread.java:1096)

Answer 1

您可以使用Application类跨多个活动访问同一个对象。

public class TestApplication extends Application {

    //Object declaration

    public TestApplication () {
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate() { 
        // TODO Auto-generated method stub
        super.onCreate();
    }

    //setter getter for object
}

现在进入您的活动：

//after setContentView
TestApplication testAppObj = (TestApplication) getApplication();
testAppObj.setSomeObj(myObj);

//retrieve as:
someObj = testAppObj.getterMethodOfObj();

希望这有帮助。

P.S：

您必须在清单文件中注册Application类，就像注册活动一样：

<application
        android:name="com.pkg.test.TestApplication " />

如何将参数活动传递给活动

1 个答案: