android - Fragments 安卓版本<3.0

Question

我想在已经扩展了 ListActivity 的 Activity 中创建 fragment 。这个fragment activity应该甚至适用于android版本<3.0

从下面的链接中，我得到了在较低的 android 版本中实现 fragment 的解决方案。他们告诉我将主要 Activity 扩展到 FragmentActivity。 Fragments in Android 2.2.1, 2.3, 2.0. Is this possible?

现在我的问题是如何将我的主 Activity 扩展到 FragmentActivity，因为它已经在扩展 ListActivity。

请帮助我。谢谢。

Answer 1

不幸的是，android 支持库不包含 FragmentListActivity。您必须通过让自定义 Listactivity 扩展 FragmentActivity 来创建您自己的。

我在 GitHub 上找到了这个类。也许你试一试 :)

*
 * Copyright (C) 2006 The Android Open Source Project
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */

import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;

/**
 * <em>Copy from Android source to enable {@link Fragment} support.</em>
 * 
 * @see ListActivity
 */
public abstract class FragmentListActivity extends FragmentActivity {

    // changed to private as original suggested
    private ListAdapter mAdapter;
    // changed to private as original suggested
    private ListView mList;

    private Handler mHandler = new Handler();
    private boolean mFinishedStart = false;

    private Runnable mRequestFocus = new Runnable() {
    public void run() {
        mList.focusableViewAvailable(mList);
    }
    };

    /**
     * This method will be called when an item in the list is selected. Subclasses should override. Subclasses can call
     * getListView().getItemAtPosition(position) if they need to access the data associated with the selected item.
     * 
     * @param l
     *            The ListView where the click happened
     * @param v
     *            The view that was clicked within the ListView
     * @param position
     *            The position of the view in the list
     * @param id
     *            The row id of the item that was clicked
     */
    protected void onListItemClick(ListView l, View v, int position, long id) {
    }

    /**
     * Ensures the list view has been created before Activity restores all of the view states.
     * 
     * @see Activity#onRestoreInstanceState(Bundle)
     */
    @Override
    protected void onRestoreInstanceState(Bundle state) {
    ensureList();
    super.onRestoreInstanceState(state);
    }

    /**
     * Updates the screen state (current list and other views) when the content changes.
     * 
     * @see Activity#onContentChanged()
     */
    @Override
    public void onContentChanged() {
    super.onContentChanged();

    // changed references from com.android.internal.R to android.R.* 
    View emptyView = findViewById(android.R.id.empty);
    mList = (ListView) findViewById(android.R.id.list);

    if (mList == null) {
        throw new RuntimeException(
            "Your content must have a ListView whose id attribute is " +
                "'android.R.id.list'");
    }
    if (emptyView != null) {
        mList.setEmptyView(emptyView);
    }
    mList.setOnItemClickListener(mOnClickListener);
    if (mFinishedStart) {
        setListAdapter(mAdapter);
    }
    mHandler.post(mRequestFocus);
    mFinishedStart = true;
    }

    /**
     * Provide the cursor for the list view.
     */
    public void setListAdapter(ListAdapter adapter) {
    synchronized (this) {
        ensureList();
        mAdapter = adapter;
        mList.setAdapter(adapter);
    }
    }

    /**
     * Set the currently selected list item to the specified position with the adapter's data
     * 
     * @param position
     */
    public void setSelection(int position) {
    mList.setSelection(position);
    }

    /**
     * Get the position of the currently selected list item.
     */
    public int getSelectedItemPosition() {
    return mList.getSelectedItemPosition();
    }

    /**
     * Get the cursor row ID of the currently selected list item.
     */
    public long getSelectedItemId() {
    return mList.getSelectedItemId();
    }

    /**
     * Get the activity's list view widget.
     */
    public ListView getListView() {
    ensureList();
    return mList;
    }

    /**
     * Get the ListAdapter associated with this activity's ListView.
     */
    public ListAdapter getListAdapter() {
    return mAdapter;
    }

    private void ensureList() {
    if (mList != null) {
        return;
    }
    // use legacy hack to get layout ID instead of com.android.internal.R.layout.list_*
    setContentView(getSupportLayoutResourceId());
    }

    /**
     * Support-hack to make legacy methods work.
     * 
     * @return the layout ID used for this {@link Activity}. This must be the same you are using with
     *         {@link #setContentView(int)}.
     */
    abstract protected int getSupportLayoutResourceId();

    private AdapterView.OnItemClickListener mOnClickListener = new AdapterView.OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View v, int position, long id)
    {
        onListItemClick((ListView) parent, v, position, id);
    }
    };
}

来源:https://gist.github.com/panzerfahrer/4201753