Android Java：设置从一个活动发送到另一个 Java 类的参数时出错

Question

I have an Activity 'LoginPage' which contains pwd and email.

Once logged in, i am sending the 'email' value as a parameter at some random point to a class 'EmailDetails' in the following manner:-

obj.setEmail(email); //where obj is object of EmailDetails

'EmailDetails' contains the following code:-

public class EmailDetails
{
    public String Usermail;

    public void setEmail(String email)
    {
       Usermail = email; //Username='null' & email='XYZ@yahoo.co.in'
    }

    public String getEmail()
    {
      return Usermail; //Username='null'
    }
}

When some other random activity 'X' wants to access 'email' value in the following manner:-

 email=obj1.getEmail(); //where obj1 is Object of EmailDetails

The 'email' value return null.

So, where am i going wrong in the code? Thanks.

Answer 1

You have to use intents to send data from one activity to another in android This link might help you http://www.c-sharpcorner.com/uploadfile/kirtan007/passing-data-from-one-activity-to-another-activity-in-android/

If this will help you accept the answer as true So,it will be helpful for others too.

Answer 2

Are you storing the data you get from user somewhere? I mean does this EmailDetails class persists somewhere outside of the login activity? try using shared preferences as most simple data persisting storage. Here's one of most popular answers on this matter on SO How to use SharedPreferences in Android to store, fetch and edit values

Hope this helps!

Answer 3

The value is null because you used this operator, it should be

public void setEmail(String email)
    {
       this.Usermail = email; //Username='null' & email='XYZ@yahoo.co.in'
    }