以下内容为原创,转载请注明:http://www.cnblogs.com/tiantianbyconan/p/3360938.html
如新浪微博下面的标签切换功能,我以前也写过一篇博文(http://www.cnblogs.com/tiantianbyconan/archive/2012/02/24/2366237.html),可以实现,用的是TabHost。但是android发展比较迅速,TabHost这玩意现在已经被弃用了,虽说用现在也能用,但是被弃用的东西还是少用为妙。
官方有个FragmentTabHost这么一个替代品,于是试了一下,发现每次切换tab,都会调用onCreateView()方法,控件被重新加载,也就是说你从tab1切换到别的tab后,再切换回来,tab1的状态并没有保存,重新加载了控件。
搞了半天,暂时没有好的解决办法(有朋友知道解决办法的话,希望联系我,赐教下哈)
于是,怒了,自己实现一个吧- -
先来看看整个demo的结构:
TabAFm到TabEFm都是Fragment,并且每个Fragment对应一个布局文件。
TabAFm.java:
class="code_img_closed" src="/Upload/Images/2013101117/0015B68B3C38AA5B.gif" alt="" />1 package com.wangjie.fragmenttabhost; 2 3 import android.app.Activity; 4 import android.os.Bundle; 5 import android.support.v4.app.Fragment; 6 import android.view.LayoutInflater; 7 import android.view.View; 8 import android.view.ViewGroup; 9 10 /** 11 * Created with IntelliJ IDEA. 12 * Author: wangjie email:tiantian.china.2@gmail.com 13 * Date: 13-6-14 14 * Time: 下午2:39 15 */ 16 public class TabAFm extends Fragment{ 17 @Override 18 public void onAttach(Activity activity) { 19 super.onAttach(activity); 20 System.out.println("AAAAAAAAAA____onAttach"); 21 } 22 23 @Override 24 public void onCreate(Bundle savedInstanceState) { 25 super.onCreate(savedInstanceState); 26 System.out.println("AAAAAAAAAA____onCreate"); 27 } 28 29 @Override 30 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 31 System.out.println("AAAAAAAAAA____onCreateView"); 32 return inflater.inflate(R.layout.tab_a, container, false); 33 } 34 35 @Override 36 public void onActivityCreated(Bundle savedInstanceState) { 37 super.onActivityCreated(savedInstanceState); 38 System.out.println("AAAAAAAAAA____onActivityCreated"); 39 } 40 41 @Override 42 public void onStart() { 43 super.onStart(); 44 System.out.println("AAAAAAAAAA____onStart"); 45 } 46 47 @Override 48 public void onResume() { 49 super.onResume(); 50 System.out.println("AAAAAAAAAA____onResume"); 51 } 52 53 @Override 54 public void onPause() { 55 super.onPause(); 56 System.out.println("AAAAAAAAAA____onPause"); 57 } 58 59 @Override 60 public void onStop() { 61 super.onStop(); 62 System.out.println("AAAAAAAAAA____onStop"); 63 } 64 65 @Override 66 public void onDestroyView() { 67 super.onDestroyView(); 68 System.out.println("AAAAAAAAAA____onDestroyView"); 69 } 70 71 @Override 72 public void onDestroy() { 73 super.onDestroy(); 74 System.out.println("AAAAAAAAAA____onDestroy"); 75 } 76 77 @Override 78 public void onDetach() { 79 super.onDetach(); 80 System.out.println("AAAAAAAAAA____onDetach"); 81 } 82 }View Code
如上述代码所示,TabAFm是一个Fragment,对应的布局文件是tab_a.xml,并实现了他的所有的生命周期回调函数并打印,便于调试
tab_a.xml布局中有个EditText
其他的Fragment大同小异,这里就不贴出代码了
现在来看MainActivity:
1 package com.wangjie.fragmenttabhost; 2 3 import android.os.Bundle; 4 import android.support.v4.app.Fragment; 5 import android.support.v4.app.FragmentActivity; 6 import android.widget.RadioGroup; 7 8 import java.util.ArrayList; 9 import java.util.List; 10 11 public class MainActivity extends FragmentActivity { 12 /** 13 * Called when the activity is first created. 14 */ 15 private RadioGroup rgs; 16 public List<Fragment> fragments = new ArrayList<Fragment>(); 17 18 public String hello = "hello "; 19 20 @Override 21 public void onCreate(Bundle savedInstanceState) { 22 super.onCreate(savedInstanceState); 23 setContentView(R.layout.main); 24 25 fragments.add(new TabAFm()); 26 fragments.add(new TabBFm()); 27 fragments.add(new TabCFm()); 28 fragments.add(new TabDFm()); 29 fragments.add(new TabEFm()); 30 31 32 rgs = (RadioGroup) findViewById(R.id.tabs_rg); 33 34 FragmentTabAdapter tabAdapter = new FragmentTabAdapter(this, fragments, R.id.tab_content, rgs); 35 tabAdapter.setOnRgsExtraCheckedChangedListener(new FragmentTabAdapter.OnRgsExtraCheckedChangedListener(){ 36 @Override 37 public void OnRgsExtraCheckedChanged(RadioGroup radioGroup, int checkedId, int index) { 38 System.out.println("Extra---- " + index + " checked!!! "); 39 } 40 }); 41 42 } 43 44 }View Code
MainActivity上述代码所示
MainActivity是包含Fragment的Activity(也就是这里的5个Fragment)
他继承了FragmentActivity(因为我这里用的是android-support-v4.jar)
用一个List<Fragment>去维护5个Fragment,也就是5个tab
main布局中有一个id为tab_content的FrameLayout,用来存放要显示的Fragment。底部有一个RadioGroup,用于tab的切换,如下:
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:orientation="vertical" 4 android:layout_width="fill_parent" 5 android:layout_height="fill_parent" 6 android:background="@android:color/white" 7 > 8 <LinearLayout 9 android:layout_width="fill_parent" 10 android:layout_height="fill_parent" 11 android:orientation="vertical" 12 > 13 14 <FrameLayout 15 android:id="@+id/tab_content" 16 android:layout_width="fill_parent" 17 android:layout_height="0dp" 18 android:layout_weight="1.0" 19 android:background="#77557799" 20 /> 21 22 <RadioGroup 23 android:id="@+id/tabs_rg" 24 android:layout_width="fill_parent" 25 android:layout_height="wrap_content" 26 android:orientation="horizontal" 27 android:gravity="center" 28 android:paddingTop="7dp" 29 android:paddingBottom="7dp" 30 > 31 <RadioButton 32 android:id="@+id/tab_rb_a" 33 android:layout_width="0dp" 34 android:layout_height="wrap_content" 35 android:drawableTop="@drawable/tablatestalert" 36 android:button="@null" 37 android:text="Tab1" 38 android:textColor="#000000" 39 android:textSize="13sp" 40 android:layout_weight="1.0" 41 android:gravity="center" 42 android:singleLine="true" 43 android:checked="true" 44 android:background="@drawable/selector_tab" 45 /> 46 <RadioButton 47 android:id="@+id/tab_rb_b" 48 android:layout_width="0dp" 49 android:layout_height="wrap_content" 50 android:drawableTop="@drawable/tabsearch" 51 android:button="@null" 52 android:text="Tab2" 53 android:textColor="#000000" 54 android:textSize="13sp" 55 android:layout_weight="1.0" 56 android:gravity="center" 57 android:singleLine="true" 58 android:background="@drawable/selector_tab" 59 /> 60 <RadioButton 61 android:id="@+id/tab_rb_c" 62 android:layout_width="0dp" 63 android:layout_height="wrap_content" 64 android:drawableTop="@drawable/tabrecommd" 65 android:button="@null" 66 android:text="Tab3" 67 android:textColor="#000000" 68 android:textSize="13sp" 69 android:layout_weight="1.0" 70 android:gravity="center" 71 android:singleLine="true" 72 android:background="@drawable/selector_tab" 73 /> 74 <RadioButton 75 android:id="@+id/tab_rb_d" 76 android:layout_width="0dp" 77 android:layout_height="wrap_content" 78 android:drawableTop="@drawable/tabconfigicon" 79 android:button="@null" 80 android:text="Tab4" 81 android:textColor="#000000" 82 android:textSize="13sp" 83 android:layout_weight="1.0" 84 android:gravity="center" 85 android:singleLine="true" 86 android:background="@drawable/selector_tab" 87 /> 88 <RadioButton 89 android:id="@+id/tab_rb_e" 90 android:layout_width="0dp" 91 android:layout_height="wrap_content" 92 android:drawableTop="@drawable/tababoutus" 93 android:button="@null" 94 android:text="Tab5" 95 android:textColor="#000000" 96 android:textSize="13sp" 97 android:layout_weight="1.0" 98 android:gravity="center" 99 android:singleLine="true" 100 android:background="@drawable/selector_tab" 101 /> 102 103 </RadioGroup> 104 </LinearLayout> 105 </LinearLayout>View Code
现在回到MainActivity中,下面这个FragmentTabAdapter类是关键,是我自己编写的用于绑定和处理fragments和RadioGroup之间的逻辑关系
FragmentTabAdapter tabAdapter = new FragmentTabAdapter(this, fragments, R.id.tab_content, rgs);
现在看下FragmentTabAdapter:
1 package com.wangjie.fragmenttabhost; 2 3 import android.support.v4.app.Fragment; 4 import android.support.v4.app.FragmentActivity; 5 import android.support.v4.app.FragmentTransaction; 6 import android.widget.RadioGroup; 7 8 import java.util.List; 9 10 /** 11 * Created with IntelliJ IDEA. 12 * Author: wangjie email:tiantian.china.2@gmail.com 13 * Date: 13-10-10 14 * Time: 上午9:25 15 */ 16 public class FragmentTabAdapter implements RadioGroup.OnCheckedChangeListener{ 17 private List<Fragment> fragments; // 一个tab页面对应一个Fragment 18 private RadioGroup rgs; // 用于切换tab 19 private FragmentActivity fragmentActivity; // Fragment所属的Activity 20 private int fragmentContentId; // Activity中所要被替换的区域的id 21 22 private int currentTab; // 当前Tab页面索引 23 24 private OnRgsExtraCheckedChangedListener onRgsExtraCheckedChangedListener; // 用于让调用者在切换tab时候增加新的功能 25 26 public FragmentTabAdapter(FragmentActivity fragmentActivity, List<Fragment> fragments, int fragmentContentId, RadioGroup rgs) { 27 this.fragments = fragments; 28 this.rgs = rgs; 29 this.fragmentActivity = fragmentActivity; 30 this.fragmentContentId = fragmentContentId; 31 32 // 默认显示第一页 33 FragmentTransaction ft = fragmentActivity.getSupportFragmentManager().beginTransaction(); 34 ft.add(fragmentContentId, fragments.get(0)); 35 ft.commit(); 36 37 rgs.setOnCheckedChangeListener(this); 38 39 40 } 41 42 @Override 43 public void onCheckedChanged(RadioGroup radioGroup, int checkedId) { 44 for(int i = 0; i < rgs.getChildCount(); i++){ 45 if(rgs.getChildAt(i).getId() == checkedId){ 46 Fragment fragment = fragments.get(i); 47 FragmentTransaction ft = obtainFragmentTransaction(i); 48 49 getCurrentFragment().onPause(); // 暂停当前tab 50 // getCurrentFragment().onStop(); // 暂停当前tab 51 52 if(fragment.isAdded()){ 53 // fragment.onStart(); // 启动目标tab的onStart() 54 fragment.onResume(); // 启动目标tab的onResume() 55 }else{ 56 ft.add(fragmentContentId, fragment); 57 } 58 showTab(i); // 显示目标tab 59 ft.commit(); 60 61 // 如果设置了切换tab额外功能功能接口 62 if(null != onRgsExtraCheckedChangedListener){ 63 onRgsExtraCheckedChangedListener.OnRgsExtraCheckedChanged(radioGroup, checkedId, i); 64 } 65 66 } 67 } 68 69 } 70 71 /** 72 * 切换tab 73 * @param idx 74 */ 75 private void showTab(int idx){ 76 for(int i = 0; i < fragments.size(); i++){ 77 Fragment fragment = fragments.get(i); 78 FragmentTransaction ft = obtainFragmentTransaction(idx); 79 80 if(idx == i){ 81 ft.show(fragment); 82 }else{ 83 ft.hide(fragment); 84 } 85 ft.commit(); 86 } 87 currentTab = idx; // 更新目标tab为当前tab 88 } 89 90 /** 91 * 获取一个带动画的FragmentTransaction 92 * @param index 93 * @return 94 */ 95 private FragmentTransaction obtainFragmentTransaction(int index){ 96 FragmentTransaction ft = fragmentActivity.getSupportFragmentManager().beginTransaction(); 97 // 设置切换动画 98 if(index > currentTab){ 99 ft.setCustomAnimations(R.anim.slide_left_in, R.anim.slide_left_out); 100 }else{ 101 ft.setCustomAnimations(R.anim.slide_right_in, R.anim.slide_right_out); 102 } 103 return ft; 104 } 105 106 public int getCurrentTab() { 107 return currentTab; 108 } 109 110 public Fragment getCurrentFragment(){ 111 return fragments.get(currentTab); 112 } 113 114 public OnRgsExtraCheckedChangedListener getOnRgsExtraCheckedChangedListener() { 115 return onRgsExtraCheckedChangedListener; 116 } 117 118 public void setOnRgsExtraCheckedChangedListener(OnRgsExtraCheckedChangedListener onRgsExtraCheckedChangedListener) { 119 this.onRgsExtraCheckedChangedListener = onRgsExtraCheckedChangedListener; 120 } 121 122 /** 123 * 切换tab额外功能功能接口 124 */ 125 static class OnRgsExtraCheckedChangedListener{ 126 public void OnRgsExtraCheckedChanged(RadioGroup radioGroup, int checkedId, int index){ 127 128 } 129 } 130 131 }View Code
这里解决Fragment切换重新加载布局的办法,用的是把几个Fragment全部Add,然后根据要显示的哪个Fragment设置show或者hide
效果输出:
10-10 11:55:41.168: INFO/System.out(18368): AAAAAAAAAA____onAttach // 第一次进入,显示TabA
10-10 11:55:41.168: INFO/System.out(18368): AAAAAAAAAA____onCreate
10-10 11:55:41.168: INFO/System.out(18368): AAAAAAAAAA____onCreateView
10-10 11:55:41.175: INFO/System.out(18368): AAAAAAAAAA____onActivityCreated
10-10 11:55:41.179: INFO/System.out(18368): AAAAAAAAAA____onStart
10-10 11:55:41.179: INFO/System.out(18368): AAAAAAAAAA____onResume
10-10 11:55:44.980: INFO/System.out(18368): AAAAAAAAAA____onPause // 从TabA切换到TabB(TabA调用onPause)
10-10 11:55:44.980: INFO/System.out(18368): Extra---- 1 checked!!!
10-10 11:55:44.996: INFO/System.out(18368): BBBBBBBBBBB____onAttach
10-10 11:55:44.996: INFO/System.out(18368): BBBBBBBBBBB____onCreate
10-10 11:55:44.996: INFO/System.out(18368): BBBBBBBBBBB____onCreateView
10-10 11:55:45.004: INFO/System.out(18368): BBBBBBBBBBB____onActivityCreated
10-10 11:55:45.004: INFO/System.out(18368): BBBBBBBBBBB____onStart
10-10 11:55:45.004: INFO/System.out(18368): BBBBBBBBBBB____onResume
10-10 11:55:52.062: INFO/System.out(18368): BBBBBBBBBBB____onPause // 从TabB切换到TabC(TabB调用onPause)
10-10 11:55:52.062: INFO/System.out(18368): Extra---- 2 checked!!!
10-10 11:55:52.082: INFO/System.out(18368): CCCCCCCCCC____onAttach
10-10 11:55:52.082: INFO/System.out(18368): CCCCCCCCCC____onCreate
10-10 11:55:52.086: INFO/System.out(18368): CCCCCCCCCC____onCreateView
10-10 11:55:52.090: INFO/System.out(18368): CCCCCCCCCC____onActivityCreated
10-10 11:55:52.090: INFO/System.out(18368): CCCCCCCCCC____onStart
10-10 11:55:52.090: INFO/System.out(18368): CCCCCCCCCC____onResume
10-10 11:56:06.535: INFO/System.out(18368): CCCCCCCCCC____onPause // 从TabC切换到TabB(TabC调用onPause)
10-10 11:56:06.535: INFO/System.out(18368): BBBBBBBBBBB____onResume // 从TabC切换到TabB(TabB调用onResume)
10-10 11:56:06.535: INFO/System.out(18368): Extra---- 1 checked!!!
好了,到此为止,我们已经用Fragment实现了类似TabHost的功能了,下面来看下各个Fragment之间的通信
现在的情况是TabAFm中有个EditText,TabBFm中有个Button,MainActivity中有个变量“hello”
要做的是,切换到TabA,输入“I'm TabA”,切换到B,点击Button后,Toast显示“hello I'm TabA”
MainActivity中没什么好说的,就一个hello变量:
public String hello = "hello ";
TabAFm在布局文件tab_a.xml中加个EditText,设置个id就可以了
TabBFm中:
1 @Override 2 public void onActivityCreated(Bundle savedInstanceState) { 3 super.onActivityCreated(savedInstanceState); 4 System.out.println("BBBBBBBBBBB____onActivityCreated"); 5 this.getView().findViewById(R.id.clickme).setOnClickListener(new View.OnClickListener() { 6 @Override 7 public void onClick(View view) { 8 // 获得绑定的FragmentActivity 9 MainActivity activity = ((MainActivity)getActivity()); 10 // 获得TabAFm的控件 11 EditText editText = (EditText) activity.fragments.get(0).getView().findViewById(R.id.edit); 12 13 Toast.makeText(activity, activity.hello + editText.getText(), Toast.LENGTH_SHORT).show(); 14 } 15 }); 16 }View Code
// 获得绑定的FragmentActivity MainActivity activity = ((MainActivity)getActivity());
通过getActivity()即可得到Fragment所在的FragmentActivity
最终效果图:
demo下载地址:http://pan.baidu.com/s/1wxsIX