在UI中动态更新Fragment中的控件监听，显示等

在开发中有时候会遇见一些的情况：根据不同的需求切换不同的fragment ,然后一些操作使当前fragment中显示的内容进行一些调整。很多时候我们都是想的在fragment添加到Activity中时通过 fragmet. getView()获取fragment对象的View 。然后用findViewById()获取到fragment中的控件对象进行操作，很悲剧的是不管用啊有木有。我是个小白，研究了近一周都没搞定，只有采用另一种方式对fragment中的控件进行操作了。

一. 发送广播更新UI

    UI中需要时发送一条广播 可顺便传入一些需要的值，在fragment中接收广播，获取值并对fragment中的控件进行操作，经本人验证完全可以。以下是Demo关键代码

在Fragment中

public class GasFragment extends Fragment {private TextView gasName;private TextView gasadderss;private ReceiveBroadCast receiveBroadCast;publicGasFragment (){}@Overridepublic void onAttach(Activity activity) {/** 注册广播 */receiveBroadCast = new ReceiveBroadCast();        IntentFilter filter = new IntentFilter();        filter.addAction("com.gasFragment");    //只有持有相同的action的接受者才能接收此广播        activity.registerReceiver(receiveBroadCast, filter);super.onAttach(activity);}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {    View view=inflater.inflate(R.layout.fragment_gas, null);gasName = (TextView) view.findViewById(R.id.frag_tv_gasname);gasadderss = (TextView) view.findViewById(R.id.fraggas_tv_adderss);        }        });return view;} class ReceiveBroadCast extends BroadcastReceiver{        @Override        public void onReceive(Context context, Intent intent)        {            //得到广播中得到的数据，并显示出来            String gasname = intent.getExtras().getString("gasName");            String address = intent.getExtras().getString("address");            gasadderss.setText("地址：\n  "+address);            gasName.setText(gasname);        }} /**  *注销广播  * */ @Override public void onDestroyView() { getActivity().unregisterReceiver(receiveBroadCast); super.onDestroyView(); } }   

在UI中

public class MainPage extends FragmentActivity {private GasFragment gasFragment;       //加油站的fragment@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main_page);        gasFragment = new GasFragment();        FragmentManager fm = getSupportFragmentManager();FragmentTransaction ft = fm.beginTransaction();ft.replace(R.id.main_fl_fragment, couponFragment);// 将帧布局替换成Fragmentft.commit();// 提交Intent intent = new Intent(); // Itent就是我们要发送的内容intent.setAction("com.gasFragment"); // 设置你这个广播的actionintent.putExtra("gasName","核反应能量加油站");intent.putExtra("address", "太平洋街11号");sendBroadcast(intent); // 发送广播}}

对应xml就不用上传了吧，很简单的布局。这样就可以动态的更新fragment中的显示内容了。

二. 通过Handler刷新Fragment

       在需要交互的Activity中建立Handler对象 具体上代码

public class MainActivity extends FragmentActivity implements OnClickListener{FrameLayout fl_replace;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);fragmentA = new FragmentA();fragmentA.setHandler(handler);fl_replace=(FrameLayout) findViewById(R.id.fl_replace);findViewById(R.id.btn_replace).setOnClickListener(this);findViewById(R.id.btn_refresh).setOnClickListener(this);findViewById(R.id.btn_return).setOnClickListener(this);}@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.btn_replace:fl_replace.setVisibility(View.VISIBLE);        FragmentManager fm=getSupportFragmentManager();        FragmentTransaction ft = fm.beginTransaction();        ft.replace(R.id.fl_replace, fragmentA);        ft.commit();break;case R.id.btn_refresh:handler.sendEmptyMessage(FragmentA.ACT_REF);break;case R.id.btn_return: fl_replace.setVisibility(View.GONE);break;}}Handler handler =new Handler(){public void handleMessage(android.os.Message msg) {switch (msg.what) {case FragmentA.ACT_REF:// 在Activity中刷新FragmentfragmentA.setTextStr("on Activity refresh ");break;case FragmentA.FRAG_REF://在Fragment中刷新FragmentfragmentA.setTextStr("on Fragment refresh ");break;}};};private FragmentA fragmentA;}

在Fragment 中获取Handler 并通过此对象发消息  代码如下

public class FragmentA extends Fragment{public static final int FRAG_REF=0;//on Fragment refresh Fragmentpublic static final int ACT_REF=1;//on Activity refresh Fragmentprivate TextView tv;public FragmentA(){}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {        View view=inflater.inflate(R.layout.frag_a, null);        tv = (TextView) view.findViewById(R.id.fragment_tv);        view.findViewById(R.id.fragment_btn).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {handler.sendEmptyMessage(FRAG_REF);}});        return view;}  Handler handler;    public void setHandler(Handler handler){    this.handler =handler;    }     public void setTextStr(String str){    tv.setText(str);    }}

handler 更新是随后添加的  所以我写了一个Demo 需要的可以去下载，一看就懂了 很简单的  http://download.csdn.net/detail/yangbo437993234/8423493

我是小白，如果有什么不足的地方请大家提出来我改正，谢谢