在 Android 项目中的列表片段中配置操作栏

Question

我正在关注这本书，并使用片段制作了一个列表视图。但我无法在该应用程序中配置操作栏，因为现在我想将选项菜单添加到操作栏。这是我在github 中的代码。如果有人能指出我应该在哪里更改代码，我将不胜感激。

我试图找出我的代码与新项目模板的不同之处，但无法弄清楚。

代码：

这是要继承给所有Activity的基础Activity

import android.os.Bundle;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;


// universal fragment activity
public abstract class SingleFragmentActivity extends FragmentActivity {

    protected abstract Fragment createFragment();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment);
        FragmentManager manager = getSupportFragmentManager();
        Fragment fragment = manager.findFragmentById(R.id.fragmentContainer);

        if (fragment == null) {
            fragment = createFragment();
            manager.beginTransaction()
                    .add(R.id.fragmentContainer, fragment)
                    .commit();
        }
    }
}

这是[R.id.fragmentContainer]使用的上述片段活动的布局文件：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/fragmentContainer">


</FrameLayout>

这是托管列表活动的活动

import android.support.v4.app.Fragment;


public class CrimeListActivity extends SingleFragmentActivity {

    @Override
    protected Fragment createFragment() {
        return new CrimeListFragment();
    }
}

这是列表片段活动：

import java.util.ArrayList;

import android.content.Intent;

import android.os.Bundle;

import android.support.v4.app.ListFragment;

import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;

import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;


public class CrimeListFragment extends ListFragment {

    private ArrayList<Crime> mCrimes;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
        getActivity().setTitle(R.string.crimes_title);
        mCrimes = CrimeLab.get(getActivity()).getCrimes();
        CrimeAdapter adapter = new CrimeAdapter(mCrimes);
        setListAdapter(adapter);
    }

    public void onListItemClick(ListView l, View v, int position, long id) {
        // get the Crime from the adapter
        Crime c = ((CrimeAdapter)getListAdapter()).getItem(position);
        // start an instance of CrimePagerActivity
        Intent i = new Intent(getActivity(), CrimePagerActivity.class);
        i.putExtra(CrimeFragment.EXTRA_CRIME_ID, c.getId());
        startActivityForResult(i, 0);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        ((CrimeAdapter)getListAdapter()).notifyDataSetChanged();
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate(R.menu.fragment_crime_list,menu);
    }

    private class CrimeAdapter extends ArrayAdapter<Crime> {
        public CrimeAdapter(ArrayList<Crime> crimes) {
            super(getActivity(), android.R.layout.simple_list_item_1, crimes);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // if we weren't given a view, inflate one
            if (null == convertView) {
                convertView = getActivity().getLayoutInflater()
                        .inflate(R.layout.list_item_crime, null);
            }

            // configure the view for this Crime
            Crime c = getItem(position);

            TextView titleTextView =
                    (TextView)convertView.findViewById(R.id.crime_list_item_titleTextView);
            titleTextView.setText(c.getTitle());
            TextView dateTextView =
                    (TextView)convertView.findViewById(R.id.crime_list_item_dateTextView);
            dateTextView.setText(c.getDate().toString());
            CheckBox solvedCheckBox =
                    (CheckBox)convertView.findViewById(R.id.crime_list_item_solvedCheckBox);
            solvedCheckBox.setChecked(c.isSolved());

            return convertView;
        }
    }
}

这是CrimeAdapter inner class [R.layout.list_item_crime] 使用的布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <CheckBox
        android:id="@+id/crime_list_item_solvedCheckBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_alignParentRight="true"
        android:enabled="false"
        android:padding="4dp"
        android:focusable="false"/>

    <TextView
        android:id="@+id/crime_list_item_titleTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_toLeftOf="@id/crime_list_item_solvedCheckBox"
        android:textStyle="bold"
        android:paddingLeft="4dp"
        android:paddingRight="4dp"
        android:text="Crime Title"/>

    <TextView
        android:id="@+id/crime_list_item_dateTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/crime_list_item_titleTextView"
        android:layout_toLeftOf="@id/crime_list_item_solvedCheckBox"
        android:paddingLeft="4dp"
        android:paddingRight="4dp"
        android:paddingTop="4dp"
        android:text="Crime Date"/>

</RelativeLayout>

那么我应该在哪里更改以添加操作栏？？

Answer 1

我做了一些简单的修改，首先编辑styles.xml：

<!-- Changed your app theme -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

然后更新 SingleFragmentActivity.java 以扩展 AppCompatActivity：

public abstract class SingleFragmentActivity extends AppCompatActivity {

    protected abstract Fragment createFragment();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment);
        FragmentManager manager = getSupportFragmentManager();
        Fragment fragment = manager.findFragmentById(R.id.fragmentContainer);

        if (fragment == null) {
            fragment = createFragment();
            manager.beginTransaction()
                    .add(R.id.fragmentContainer, fragment)
                    .commit();
        }
    }
}

然后创建了一个 menu_list.xml：

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="Settings"
        app:showAsAction="ifRoom"/>
</menu>

然后让 CrimeListActivity 膨胀并处理选项菜单点击：

public class CrimeListActivity extends SingleFragmentActivity {

    @Override
    protected Fragment createFragment() {
        return new CrimeListFragment();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_list, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int itemId = item.getItemId();

        if(itemId == R.id.action_settings){

            // Handle the action

            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

这只会将它添加到您的一个 CrimeListActivity 中。全面做出改变。您需要拥有所有不使用 SingleFragmentActivity extend AppCompatActivity 的 Activity 类

说明

这些更改起作用的基本原因：

1. FragmentActivity 不知道ActionBar，如果您想要具有ActionBar 的东西，您需要使用更新但现已弃用的Activity，它扩展了FragmentActivity 调用@987654331 @

2. ActionBarActivity 现在已弃用并替换为 AppCompatActivity，当您的案例中应用正确的主题时，AppCompatActivity 确实知道 ActionBar Theme.AppCompat.Light.DarkActionBar 可以解决此问题。

祝你好运，编码愉快！