How can I use the Android back button to move back within my app instead of closing my app?

问题

My app has three activities, A, B and C. I am moving from A to B through an OK button, and I want to move back from B to A by using the default back button of Android devices. When I press the button, though, the entire app gets closed. How can I get around this problem?

回答1:

I suspect you call finish() in your OK button onclick listener. Don't do that. finish() removes your activity from activity stack.

回答2:

why start your activity for result ? when you press the backbutton, the result is set to RESULT_CANCELED form the B activity, so it crashes if you don't handle the resultcode...

you can handle the backpress like this

private static final int NONE = -1;

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_BACK) {

   setResult(NONE, intent);
        finish();
    return super.onKeyDown(keyCode, event);
}

回答3:

When you are Ok button r u starting an intent...like

Intent int=new intent(context,B.class); startActivity(int);

then if you are not handling backbutton.

If use default back button...it will goes back to A.

Hope it helps...

回答4:

In my onClick method (in Main Activity) I use the code:

 Intent intent = new Intent(context, SecondActivity.class);
 context.startActivityForResult(intent, SecondActivity.SECONDACTIVITY_REQUEST);

In the manifest I've got:

 <activity android:name=".SecondActivity" android:screenOrientation="landscape" android:launchMode="standard"></activity>

This works for me without any other settings that I can see. What events are you responding to?

Note that you can also go back an activity, in code like this:

super.setResult(Activity.RESULT_OK);
super.finish();

Edit... Make sure you're not swallowing the event in the Main Activitys onKeyDown event.

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    //your code here
    //if (keyCode ==
    //...
    //else
    return super.onKeyDown(keyCode, event);
}

来源：https://stackoverflow.com/questions/5406919/how-can-i-use-the-android-back-button-to-move-back-within-my-app-instead-of-clos

标签

java

android

callback