使用“ onBackPressed（）”使开始的活动返回到先前的屏幕

Question

I have an activity which is repeated "x" times with this piece of code :

//create intent to start itself again with different parameters
            Intent intent = getIntent();

            intent.putExtra(CATEGORY_ID, temp.getCat_ID());
            intent.putExtra(CATEGORY_SHOPID, temp.getShopID());
            intent.putExtra(CATEGORY_SITEID, temp.getSiteID());
            intent.putExtra(CATEGORY_NAME, temp.getCat_Name());

            finish();
            startActivity(intent);

My goal is that when the user presses the back button that the same activity gets started as there was before with the same parameters as before and such. I tried saving them in an Activity ArrayList but that doesn't seem to work.

Answer 1

When you call finish, your activity will end. When you don't call finish, your activity just go to the background. In that case, when you press the backbutton in your new activity, your previous activity comes up.

I think when you just delete finish(), it will work.

Answer 2

It's okay if you save the parameters you've already set earlier, but you need to retrieve all that information from the Intent itself and repopulate your activity with the proper data.

This must be done like this:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    String categoryId = getIntent().getStringExtra(CATEGORY_ID);

    // retrieve the others and populate your activity 

}

Answer 3

in your activity, get event back

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK ) {
        // and you have to make a intent to call this activity again with parameter other
        finish(); // and call finish() here to close the old activity
    }
    return super.onKeyDown(keyCode, event);
}

hope this help!

Answer 4

您是否尝试覆盖onBackPressed方法？