在Android中设置root活动/意图

Question

I'm switching between different Activities using Intents. For one Activity, I would like it to clear the history stack so when the user presses the back button, it takes them Home instead of previous activities in my application.

Answer 1

I had to implement the same thing for my project. What I ended up doing was to replace: startActivity(i); with startActivityForResult(i, UniqueId); in all the activities I wanted to be part of the "history stack".

Then implemented:

setResult(UniqueId);
finish();

in the child activity when I wanted to close the child and return to "home/root".

In the parent activity, I implemented:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == UniqueId && resultCode == UniqueId) {
 setResult(UniqueId);
 finish();
}
super.onActivityResult(requestCode, resultCode, data);
}

Which effectively means if the child activity sent a "home/root" result (represented by UniqueId), all parents of that child activity that have used "startActivityForResult(i, UniqueId);" will close as well.

Hope that makes sense?

Answer 2

You could try calling finish() on the activities you don't want to keep around when calling startActivity ?

Or, the less android solution, listen for onBackPressed() in your activities and then call startActivity() on your main activity with the CLEAR_STACK flag set.