Android：是否有可能在未来进行一些活动？

Question

For example: I have 5 activities:

Activity A --> Activity B --> Activity C --> Activity D --> Activity E

Activity A must go through Activity B then C then D then E in sequence .

I want to pass an intent in Activity A to Activity E without passing it through B, C, D.

Is it possible to do that?

My passing intent in Activity A currently:

fab = (FloatingActionButton) rootView.findViewById(R.id.fabAddConList);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent createContactList = new Intent(context, ActivityB.class);
                createContactList.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
                createContactList.putExtra("userid", userID);
                startActivity(createContactList);
            }
        });

My receiving intent in Activity E currently:

 Intent lastIntent = getIntent();
        userid = lastIntent.getStringExtra("userid");

-----------------------------------EDIT-----------------------------------------

As based on my codes in this post, I am passing the intent in Activity A to Activity B instead of E, because I want to go to Activity B when I click the button. But how can I go to Activity B without passing the "userid" to Activity B and keep it till it reached Activity E?

Answer 1

No, it is not possible to have an Activity pass an Intent to the next Activity in the sequence without first receiving that Intent . How else to pass it on?

In your case, consider writing the piece of information for Activity E to SharedPreferences . They use key-value pairs for storing data just like intents do, see also this link to documentation .

By the way, from a security point of view: at least in some versions of android, the Intent used with startActivity() is not private to your app. So be careful not to pass sensitive data with startActivity() .

Answer 2

Yes, As long as intent is not clear everything will pass with intent from start to end. Whenever you want to clean intent data you can call

getIntent().removeExtra("key"); 

If you want to forward the intent. You can do it by

Intent newIntent = new Intent(receivedIntent);

Answer 3

No, you have to pass value from all activities.

Otherthan this you can use SharedPreferences to store value in Activity A and fetch that value in Activity E . check this for reference.

Other way is static variable, take public static variable in A and access it from Activity E

in Activity A

public static String yourVariable="value";

in Activity E access it by using A.yourVariable

Answer 4

For my app, the user will have to go through activity A to E in sequence. The user cannot go from Activity A to Activity E straight without passing B,C and D. Can I still pass the intent from A to E when process is still going in sequence like A,B,C,D, E?

your all activity in sequence then you must have to pass value from all activities using intent.

alternative

use Preference to store your value or static variable

Answer 5

One option is to use a public static variable (or singleton) to store a value to be read at a later point by another activity. Usually you don't want to use statics like this, but it might be the easiest thing for you to do.

This is basic application of static variables in Java. Declare a new class with the state you want to retain:

public class State {
    public static String value;
}

In Activity A:

State.value = "value that you want to read in activity E"

In Activity E:

String v = State.value;