CODEWITHSUNDEEP
androidmemory-leaksandroid-activitycomponents
user1118019
user1118019

Reputation: 3969

Android use component name to launch an activity

There are many ways to start another activity. The most of the overloading methods requires you to pass a context.

But when using componentName to launch an activity using

public Intent setComponent (ComponentName component)

and this constructor for ComponentName

ComponentName(String pkg, String cls)

You see above, I am able to launch an activity WITHOUT using any Context argument

But it must use some "context" somehow internally, am I right? If so, which context? Application one or the activity one? Does this mean that every time I use this two methods (above), I do not need to worry about memory leak becuase I am not passing any context around??

Thanks

Upvotes: 5

Views: 10257

Answers (4)

Squonk
Squonk

Reputation: 48871

adamp's answer is correct (he got to it before I could post).

Just to expand on it this is the source for the Intent(Context packageContext, Class<?> cls) constructor...

public Intent(Context packageContext, Class<?> cls) {
    mComponent = new ComponentName(packageContext, cls);
}

...and this is the source for ComponentName(Context pkg, Class<?> cls) constructor

public ComponentName(Context pkg, Class<?> cls) {
    mPackage = pkg.getPackageName();
    mClass = cls.getName();
}

As adamp implies, the Intent methods that take a Context are convenience methods that only use it to create the ComponentName which in turn only deals in String types (mPackage and mClass). Neither the Intent nor the ComponentName hold a reference to the Context.

Upvotes: 5

adamp
adamp

Reputation: 28932

You don't have to worry about memory leaks in either case, but it's good that you're keeping an eye on where you're passing Context objects. Intent simply uses the Context parameter to look up your package name when you use the Intent(Context, Class) constructor or setClass(Context, Class) method. They're just convenience methods.

Upvotes: 5

Yury
Yury

Reputation: 20936

Maybe I did not understand your question. But you do not use context when you defining intents. You use context to call components using intents. For instance, you use:

context.startActivity(intent)

But usually you call these methods inside your Activities and Services, that extends Context. Thus, you simply use:

startActivity(intent)

Upvotes: 0

mah
mah

Reputation: 39827

startActivity() does not require a context as a parameter; it's a method within a class which is already derived from (or implements) Context. That is -- you cannot call startActivity() if you do not have a Context from which to call it.

Upvotes: 0

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