Android 开发Fragment类似微信主页切换

Fragment（碎片）

Fragment可以实现在一个Activity下显示多个视图，类似于微信首页底部栏切换。

一、在需要用到Fragment视图中的Activity

public class NewsActivity extends FragmentActivity implements OnClickListener {    // 底部菜单3个Linearlayout    private LinearLayout message;    private LinearLayout fair;    private LinearLayout question;    // 3个Fragment    private Fragment first_f;    private Fragment two_f;    private Fragment three_f;        private FragmentManager manager;    private FragmentTransaction transaction;    @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_news); initView();       // 初始化控件                         initEvent();// 初始化按钮事件                 // 初始化并设置当前Fragment                initFragment(0);    }    private void initFragment(int index) {        // 由于是引用了V4包下的Fragment，所以这里的管理器要用getSupportFragmentManager获取        FragmentManager fragmentManager = getSupportFragmentManager();        // 开启事务        FragmentTransaction transaction = fragmentManager.beginTransaction();        // 隐藏所有Fragment        hideFragment(transaction);        switch (index) {        case 0:            if (first_f == null) {                first_f = new NewsOne();      //NewsOne是fragment视图1                transaction.add(R.id.fl_content, first_f);            } else {                transaction.show(first_f);            }            break;        case 1:            if (two_f == null) {            two_f = new NewsTwo();         //NewsTwo是fragment视图2                transaction.add(R.id.fl_content, two_f);            } else {                transaction.show(two_f);            }            break;        case 2:            if (three_f == null) {            three_f = new NewsThree();         //Newsthree是fragment视图3                transaction.add(R.id.fl_content, three_f);            } else {                transaction.show(three_f);            }            break;           default:            break;        }        // 提交事务        transaction.commit();    }    //隐藏Fragment    private void hideFragment(FragmentTransaction transaction) {        if (first_f != null) {            transaction.hide(first_f);        }        if (two_f != null) {            transaction.hide(two_f);        }        if (three_f != null) {            transaction.hide(three_f);        }    }    private void initEvent() {        // 设置按钮监听        message.setOnClickListener(this);        fair.setOnClickListener(this);        question.setOnClickListener(this);    }    private void initView() {        // 底部菜单4个ImageView        this.message = (LinearLayout) findViewById(R.id.message);        this.fair = (LinearLayout) findViewById(R.id.fair);        this.question = (LinearLayout) findViewById(R.id.question);    }    @Override    public void onClick(View v) {        // 在每次点击后将所有的底部按钮(ImageView,TextView)颜色改为灰色，然后根据点击着色       restartButton();        // ImageView和TetxView置为绿色，页面随之跳转        switch (v.getId()) {        case R.id.message:            message.setBackgroundResource(R.drawable.msg_after_bg);            initFragment(0);            break;        case R.id.fair:        fair.setBackgroundResource(R.drawable.msg_after_bg);            initFragment(1);            break;        case R.id.question:        question.setBackgroundResource(R.drawable.msg_after_bg);            initFragment(2);            break;        default:            break;        }    }    private void restartButton() {        // ImageView置为灰色        message.setBackgroundResource(R.drawable.msg_before_bg);        fair.setBackgroundResource(R.drawable.msg_before_bg);        question.setBackgroundResource(R.drawable.msg_before_bg);    }}

二、对应的Fragment视图NewsOne、NewsTwo、NewsThree

在对应的Fragment中：

    public View onCreateView(LayoutInflater inflater,  ViewGroup container,  Bundle savedInstanceState) {        View view = inflater.inflate(R.layout.activity_news_three, container, false);    return view;            }