Different flow in the Android Activity Stack?

I have a set of activities A, B, C.

The user can go A->B->C->B->C->B. I don't want B and C to be repeating like this. Is there any intent flag I can set to limit this to A->B->C so that 开发者_如何转开发the user doesn't have to press the back button many times?

Thank you

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Use FLAG_ACTIVITY_REORDER_TO_FRONT.

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Add following attribute to your AndroidManifest.xml. You should add this attribute to each activity's block, which you want to initialize only once and preserve it's state during application lifetime:

    android:launchMode="singleTask" 

And use following sample of code to switch between activities:

    Intent i = new Intent(C.this, B.class);
    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    startActivity(i);

You also can use Intent.FLAG_ACTIVITY_REORDER_TO_FRONT, but launchMode should be set to "singleTask" too.