Question

我有NavigationDrawer根据菜单上的选定值调用其他页面。它是通过片段加载的。

MainActivity.Java

package medapp.app;

import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends Activity
{
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    private String[] mActions;



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

        mTitle = mDrawerTitle = getTitle();
        mActions = getResources().getStringArray(R.array.action_array);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        // set a custom shadow that overlays the main content when the drawer opens
        //mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
        // set up the drawer's list view with items and click listener
        mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                R.layout.drawer_list_item, mActions));
        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        // enable ActionBar app icon to behave as action to toggle nav drawer
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the sliding drawer and the action bar app icon
        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  /* host Activity */
                mDrawerLayout,         /* DrawerLayout object */
                R.drawable.ic_drawer,  /* nav drawer image to replace 'Up' caret */
                R.string.drawer_open,  /* "open drawer" description for accessibility */
                R.string.drawer_close  /* "close drawer" description for accessibility */
        ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            selectItem(0);
        }
    }

    public void onItemClick(AdapterView<?> adapter, View view,
                            int position, long id) {
        Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
                Toast.LENGTH_SHORT).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        return super.onPrepareOptionsMenu(menu);
    }


    /* */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // The action bar home/up action should open or close the drawer.
        // ActionBarDrawerToggle will take care of this.
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
                return super.onOptionsItemSelected(item);
        //}
    }


    /* The click listener for ListView in the navigation drawer */
    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    private void selectItem(int position) {
        // update the main content by replacing fragments
        Fragment fragment = new ActionFragment();
        Bundle args = new Bundle();
        args.putInt(ActionFragment.ARG_ACTION1_NUMBER, position);
        fragment.setArguments(args);

        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        setTitle(mActions[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getActionBar().setTitle(mTitle);
    }

    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }


}

HERE是我的 Fragment.Java ，它为每个选项调用xml布局。

package medapp.app;

import android.app.*;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import org.json.JSONArray;
import org.json.JSONException;

public class ActionFragment extends Fragment
{
    public static final String ARG_ACTION1_NUMBER = "Fragment_layout";
    public JSONArray blogData;

    public ActionFragment() {
        // Empty constructor required for fragment subclasses
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_layout, container, false);
        int i = getArguments().getInt(ARG_ACTION1_NUMBER);

        if (i == 0)
        {
            rootView = inflater.inflate(R.layout.fragment_layout, container, false);
        }
        else if(i == 1)
        {
            PostActivity getBlogPostTask = new PostActivity();
            getBlogPostTask.execute();
            rootView = inflater.inflate(R.layout.fragment_articles, container, false);
        }
        else if(i == 2)
        {
            rootView = inflater.inflate(R.layout.fragment_news, container, false);
            PostActivity getBlogPostTask = new PostActivity();
            getBlogPostTask.execute();
        }
        else if(i == 3)
        {
            rootView = inflater.inflate(R.layout.fragment_signin, container, false);
        }
        return rootView;
    }

    public void updatelist() {

        if (blogData == null)
        {
            // TODO: update list when null.
        }
        else
        {
            try
            {
               Log.d("TAG", blogData.toString(2));
            } catch (JSONException e) {
                Log.e("TAG", "Exception Caught: ", e);
            }
        }
    }

}

现在我创建了layout_listitem.xml我要在fragment_article.xml内加载作为列表视图中的项目。

知道如何在layout_listitem的listview中将fragment_article.xml展示作为布局设计。

我在互联网上找到的所有教程都要求在主要活动中调用fragment_article.xml。

Answer 1

您可以像ListView这样获得fragment_articles：

PostActivity getBlogPostTask = new PostActivity();
getBlogPostTask.execute();
rootView = inflater.inflate(R.layout.fragment_articles, container, false);

ListView listView = (ListView) rootView.findViewById(R.id.list);  // assuming that the id of your listview in xml file is "list"

现在，您需要创建一个扩展BaseAdapter或ArrayAdapter的适配器类。在该适配器的getView方法中，您需要为layout_listitem充气。

public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater)
                context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(R.layout.layout_listitem, null);
    }

    .....................

    return view;
}

之后，将自定义适配器设置为列表视图的数据源。

Adapter adapter = new MyCustomAdapter(...);
listView.setAdapter(adapter);

Answer 2

如果您知道fragment_article.xml为您提供了ListView.java，那么以下代码可以解决您的问题。

else if(i == 1) 
{
    PostActivity getBlogPostTask = new PostActivity();
    getBlogPostTask.execute();
    rootView = inflater.inflate(R.layout.fragment_articles, container, false);
    ListView listView = (ListView) rootView;
    //convert JSONArray to ArrayList<JSONObject>
    List<JSONOject> data = //convert blogData
    ArrayAdapter<JSONObject> adapter = new ArrayAdapter<JSONObject(getActivity(), R.layout.layout_listitem.xml, data);
    listView.setAdapter(adapter); 
}

没有必要在这里写更多代码。这取决于您计划如何加载数据。

您需要了解进一步增强功能的内容：

上面代码中的ArrayAdapter将获取JSONObject.toString值并在layout_listitem.xml上调用setText，假设它是TextView。我想不是这样，你可以扩展ArrayAdapter并覆盖方法getView（）。
您可以将ArrayAdapter保留为ActionFragment的成员，并为每个ARG_ACTION1_NUMBER类型对其进行不同的初始化。如果您计划使用相同的数据但以不同的布局显示，这将非常有用。此外，如果您计划在ActionFragment之外加载数据，那么在updateList（）方法中，您可以轻松访问该适配器。
如果您知道要加载的JSON，请考虑创建Java POJO并使用GSON或Jackson库。然后在您的适配器中，您可以拥有自己的类。使用POJO比自己解析JSON要容易得多。

在片段创建的列表视图上加载布局

2 个答案: