Question

当我使用设备的后退按钮从我的第二个Activity下方返回我的第一个MainActivity.java（MainActivity2.java）时，我的第一个{{1}每次调用Activity方法，但如果我使用onCreate()后退按钮，则不会调用ActionBar方法。

MainActivity.java

onCreate()

MainActivity2.java

package exam.mcq.it.intentdemo;

import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity {

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

        Toast.makeText(this,"Create method call",Toast.LENGTH_SHORT).show();

        Button btn=(Button)findViewById(R.id.btnClick);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in=new Intent(MainActivity.this,MainActivity2.class);
                startActivity(in);
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

AndroidMainfest.xml

package exam.mcq.it.intentdemo;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;


public class MainActivity2 extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_activity2);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main_activity2, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Answer 1

我有同样的问题。我使用了一个小黑客，不确定这是否是正确的方法。当按下箭头时，我调用了onBackPressed（）方法。

@Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId())
    {
        case R.id.action_save:
                            save();
                            return true;
        case android.R.id.home:
            //Pressing on up Arrow was calling onCreate of MainActivity
            getActivity().onBackPressed();
            return true;
    }

你的问题不明确所以我假设你不想在按下actionBar中的箭头时调用onCreate（）。

Answer 2

覆盖活动中的onBackPressed ()功能。使用背按按钮时将调用该功能。另外，请参考docs

中活动的生命周期

ActionBarActivity无法从popstack解析

2 个答案: