Android 如何从导航抽屉中打开新片段？

我正在使用developer.android.com指南构建一个应用程序。当我在Android Studio中创建一个新项目时，我选择了“导航：导航抽屉”。我在互联网上搜索了我的问题的答案，但我找不到任何有效的答案。很抱歉，我是编程新手

在导航抽屉中单击时，如何使我的应用程序在主视图中打开新片段

在导航抽屉中单击时，是否可以使用选项卡打开多个可切换片段

如何使“标题”可展开/折叠

这就是我想要的布局：

---

标题（章节*而非章节（标题；）

导航抽屉是当今一种新的时尚设计。在为导航抽屉活动设计xml.layout（layout）时，我们使用两种布局：主内容布局和抽屉列表布局。我在这里回答你所有愚蠢的问题

我如何使我的应用程序在主视图中打开一个新片段 在导航抽屉中单击

只需在抽屉列表项上添加clicklistener，并根据单击的列表项的位置替换主要内容中的片段

示例代码：

    // The click listener for ListView in the navigation drawer
    @SuppressWarnings("unused")
    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) {

        Fragment newFragment;
        FragmentTransaction transaction = getFragmentManager().beginTransaction();

        switch (position) {
        case 0:
            newFragment = new f1();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 1:
            newFragment = new f2();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 2:
            newFragment = new f3();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;

        case 3:
            newFragment = new f4();
            transaction.replace(R.id.content_frame, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();
            break;  


        }
        //DrawerList.setItemChecked(position, true);
        setTitle(ListTitles[position]);
        DrawerLayout.closeDrawer(DrawerList);   
    }

另一个片段的代码。i、 e F_tab2.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class F_tab2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.friends_list, container,false);


        return view;
    }

}

现在，只需在抽屉列表中使用前面提到的clicklistener，即可在项目上加载F_main，单击抽屉列表，这将进一步在主内容视图中加载F_main fragmnet中的选项卡

如何使“标题”可展开/折叠

我不知道NV抽屉是否提供此功能。但它提供了一个功能，可以根据选定的抽屉项目或加载的主要内容片段切换操作栏标题

如《导航抽屉设计指南》中所述，当抽屉可见时，应修改操作栏的内容，例如更改标题并删除与主要内容相关的操作项。下面的代码显示了如何通过使用ActionBarDrawerToggle类的实例重写DrawerLayout.DrawerListener回调方法来实现这一点，如下所示

 public class MainActivity extends Activity {
    private DrawerLayout mDrawerLayout;
    private ActionBarDrawerToggle mDrawerToggle;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    ...

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

        mTitle = mDrawerTitle = getTitle();
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };

        // Set the drawer toggle as the DrawerListener
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    /* 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);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }
    }

---

+1为伟大的油漆使用技能…真棒！这是一个很好的答案！非常感谢这是一个非常详细的答案，太棒了！通过这种方式，如果您在同一导航抽屉项目上单击两次，那么您将获得相同的片段，并将其添加到后堆栈中两次（即，如果您按下“后退”按钮，您将看到相同的片段，而不是上一个片段）。@Aman_devy，以及如何通过另一个活动打开抽屉中的特定片段？每次您只是通过“newFragment=new f1（）；”创建一个新片段，这是一个好的做法吗？您认为将所有片段作为成员变量保存会更好吗？因此，每次用户单击菜单项时，只需使用“transaction.replace（R.id.content_frame，MFFragment1）”，无需创建新的片段。

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class F_tab1 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.friends_list, container,false);


        return view;
    }

}

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class F_tab2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.friends_list, container,false);


        return view;
    }

}

 public class MainActivity extends Activity {
    private DrawerLayout mDrawerLayout;
    private ActionBarDrawerToggle mDrawerToggle;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    ...

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

        mTitle = mDrawerTitle = getTitle();
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };

        // Set the drawer toggle as the DrawerListener
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    /* 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);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }
    }