如何在活动中接收意向

Question

老实说，我在询问之前对此进行了一些搜索。 如何从活动接收意向fragmentactivity 我正在尝试使用查看页。我在获取参数时遇到错误Bundle extras = getArguments();

public class SingleViewActivity extends FragmentActivity {
    ImageView   imageView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_page_view);
   ArrayList<Listitem> personArrayList = new ArrayList<Listitem>();
       // Listitem item = new Listitem("1", "http://developer.android.com/assets/images/android_logo.png");//I used to add it staticly
        Bundle extras = getArguments();
        if (extras != null) {
            extras = extras.getParcelableArrayList(ARG_PERSON_LIST);
            personArrayList.add(item);        }
    //    DemoObjectFragment f = DemoObjectFragment.newInstance(personArrayList);
        ViewPager    mViewPager = (ViewPager) findViewById(R.id.pager);
        Log.d("s", "singleview");

        DemoCollectionPagerAdapter mDemoCollectionPagerAdapter =      new DemoCollectionPagerAdapter( getSupportFragmentManager(),personArrayList);
        mViewPager.setAdapter(mDemoCollectionPagerAdapter);

Answer 1

您将需要两个活动。由于您没有发布启动已发布Activity的Activity，因此我制作了一个简单的Button，仅包含一个启动所显示Activity的。

记下注释的步骤。总共有六个步骤。

第一个Activity获取ArrayList数据，将其传递给第二个Activity，后者又交给DemoCollectionAdapter。

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // Step 1: Build an ArrayList to pass to the next Activity
                ArrayList<Listitem> items = new ArrayList<Listitem>();
                items.add(new Listitem("1", "http://developer.android.com/assets/images/android_logo.png"));
                items.add(new Listitem("2", "https://i.stack.imgur.com/B28Ca.jpg?s=328&g=1"));
                // Step 2: Create an Intent to start the next Activity
                Intent intent = new Intent(getApplicationContext(), SingleViewActivity.class);
                // Step 3: Put the ArrayList into the Intent
                intent.putParcelableArrayListExtra(SingleViewActivity.ARG_PERSON_LIST, items);
                // Step 4: Start the next Activity
                startActivity(intent);
            }
        });
    }
}

---

public class SingleViewActivity extends FragmentActivity {
    public static final String ARG_PERSON_LIST = "ARG_PERSON_LIST";
    private ArrayList<Listitem> items;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_page_view);
        // Step 5: Get the Bundle from the Intent that started this Activity
        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            // Step 6: Get the data out of the Bundle
            items = extras.getParcelableArrayList(ARG_PERSON_LIST);
        } else {
            items = new ArrayList<Listitem>();
        }
        ViewPager pager = (ViewPager) findViewById(R.id.pager);
        DemoCollectionPagerAdapter adapter = new DemoCollectionPagerAdapter(getSupportFragmentManager(), items);
        pager.setAdapter(adapter);
    }
}

Answer 2

您正在将 ParcelableList 对象分配给 Bundle 变量。

extras = extras.getParcelableArrayList(ARG_PERSON_LIST); //change it

将其分配给ParcelableList而不是extras。

编辑：

试试这个，

ArrayList<Listitem> personArrayList;
// Listitem item = new Listitem("1", "http://developer.android.com/assets/images/android_logo.png");//I used to add it staticly
Bundle extras = getArguments();
if (extras != null) {
    personArrayList = (ArrayList<Listitem>) extras.getParcelableArrayList("jh");
    personArrayList.add(item); 
    ....       
}

Answer 3

创建片段对象时，您还在创建的片段对象中设置了参数。

像这样的东西...

Fragment f = new Fragment();
Bundle args = new Bundle();
args.putInt("someNum", 0);
f.setArguments(args);

然后在片段的onCreate（）或onCreateView方法中，获取参数。

getArguments().getInt("someNum");

在您的情况下，它将是可包裹或可序列化的对象。