我试图做到这一点: HTTP: //android-er.blogspot.com/2012/06/communication-between-fragments-in.html 除我使用FragmentStatePagerAdapter
我有一个活动有两个片段(碎裂&安培; FragmentB )
碎裂有一个EditText和一个按钮,FragmentB有一个TextView
现在我要的是,每当我进入东西在的EditText并单击按钮时,事情会出现在我的TextView。
MainActivity:
公共类MainActivity扩展FragmentActivity {
ViewPager viewPager = NULL;
字符串TabFragmentB;
@覆盖
保护无效的onCreate(包savedInstanceState){
super.onCreate(savedInstanceState);
的setContentView(R.layout.activity_main);
viewPager =(ViewPager)findViewById(R.id.pager);
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager.setAdapter(新MyAdapter(fragmentManager));
}
公共类MyAdapter扩展FragmentStatePagerAdapter {
公共MyAdapter(FragmentManager FM){
超(FM);
}
@覆盖
公共片段的getItem(int i)以{
片段片段= NULL;
如果(我== 0)
{
片段=新碎裂();
}
如果(ⅰ== 1)
{
片段=新FragmentB();
}
返回片段;
}
@覆盖
公众诠释getCount将(){
返回2;
}
}
公共无效setTabFragmentB(串T){
TabFragmentB = T;
}
公共字符串getTabFragmentB(){
返回TabFragmentB;
}
}
碎裂:
公共类碎裂扩展片段{
的EditText等;
按钮胜;
@覆盖
公共查看onCreateView(LayoutInflater充气,容器的ViewGroup,
捆绑savedInstanceState){
视图V = inflater.inflate(R.layout.fraga,集装箱,假);
等=(EditText上)v.findViewById(R.id.edit1);
BT =(按钮)v.findViewById(R.id.button1);
bt.setOnClickListener(点击);
返回伏;
}
OnClickListener点击=新OnClickListener(){
@覆盖
公共无效的onClick(视图v){
。字符串textPassToB = et.getText()的toString();
串TabOfFragmentB =((MainActivity)getActivity())getTabFragmentB()。
FragmentB fragmentB =(FragmentB)getActivity()
.getSupportFragmentManager()
.findFragmentByTag(TabOfFragmentB);
fragmentB.updateText(textPassToB);
}
};
}
FragmentB:
公共类FragmentB扩展片段{
TextView的电视;
@覆盖
公共查看onCreateView(LayoutInflater充气,容器的ViewGroup,
捆绑savedInstanceState){
视图V = inflater.inflate(R.layout.fragb,集装箱,假);
电视=(TextView中)v.findViewById(R.id.text1);
串MyTag的= getTag();
((MainActivity)getActivity())setTabFragmentB(MyTag的)。
返回伏;
}
公共无效UPDATETEXT(串T){
tv.setText(T);
}
}
LogCat中:
致命异常:主要
显示java.lang.NullPointerException
在lmf.sample1.FragmentA $ 1.onClick(FragmentA.java:43)
在android.view.View.performClick(View.java:4212)
在android.view.View $ PerformClick.run(View.java:17476)
在android.os.Handler.handleCallback(Handler.java:800)
在android.os.Handler.dispatchMessage(Handler.java:100)
在android.os.Looper.loop(Looper.java:194)
在android.app.ActivityThread.main(ActivityThread.java:5371)
在java.lang.reflect.Method.invokeNative(本机方法)
在java.lang.reflect.Method.invoke(Method.java:525)
在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:833)
在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
在dalvik.system.NativeStart.main(本机方法)
每当我点击我的第一个片段,我的应用程序崩溃的按钮。到底是什么问题?
解决方案 您可以使用意图(注册广播接收器在B片段和片段A.发送广播 使用EventBus: https://github.com/greenrobot/EventBus 。这是我最喜欢的方式。十分便利使用,任何组件之间的便捷通信(活动及放大器;服务,例如)。步骤做:
首先,创建一些类来重新present事件时,你的文字变化:
公共类TextChangedEvent {
公共字符串newText;
公共TextChangedEvent(字符串newText){
this.newText = newText;
}
}
然后,在片段答:
//当文字变化
EventBus总线= EventBus.getDefault();
bus.post(新TextChangedEvent(newText));
在B片段:
EventBus总线= EventBus.getDefault();
//注册EventBus
@覆盖
公共无效的onCreate(SavedInstanceState savedState){
bus.register(本);
}
//渔获物片段A事件
公共无效的onEvent(TextChangedEvent事件){
yourTextView.setText(event.newText);
}
I'm trying to do this: http://android-er.blogspot.com/2012/06/communication-between-fragments-in.html Except that I'm using a FragmentStatePagerAdapter
I have an Activity with two fragments(FragmentA & FragmentB)
FragmentA has an edittext and a button, FragmentB has a textview
Now all I want is that whenever I enter something in the edittext and click the button, that something will appear on my textview.
MainActivity:
public class MainActivity extends FragmentActivity {
ViewPager viewPager = null;
String TabFragmentB;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager)findViewById(R.id.pager);
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager.setAdapter(new MyAdapter(fragmentManager));
}
public class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter (FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
Fragment fragment = null;
if (i == 0)
{
fragment = new FragmentA();
}
if (i == 1)
{
fragment = new FragmentB();
}
return fragment;
}
@Override
public int getCount() {
return 2;
}
}
public void setTabFragmentB(String t) {
TabFragmentB = t;
}
public String getTabFragmentB() {
return TabFragmentB;
}
}
FragmentA:
public class FragmentA extends Fragment {
EditText et;
Button bt;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fraga, container, false);
et = (EditText)v.findViewById(R.id.edit1);
bt = (Button)v.findViewById(R.id.button1);
bt.setOnClickListener(Click);
return v;
}
OnClickListener Click = new OnClickListener(){
@Override
public void onClick(View v) {
String textPassToB = et.getText().toString();
String TabOfFragmentB = ((MainActivity)getActivity()).getTabFragmentB();
FragmentB fragmentB = (FragmentB)getActivity()
.getSupportFragmentManager()
.findFragmentByTag(TabOfFragmentB);
fragmentB.updateText(textPassToB);
}
};
}
FragmentB:
public class FragmentB extends Fragment {
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragb, container, false);
tv = (TextView)v.findViewById(R.id.text1);
String myTag = getTag();
((MainActivity)getActivity()).setTabFragmentB(myTag);
return v;
}
public void updateText(String t){
tv.setText(t);
}
}
LogCat:
FATAL EXCEPTION: main
java.lang.NullPointerException
at lmf.sample1.FragmentA$1.onClick(FragmentA.java:43)
at android.view.View.performClick(View.java:4212)
at android.view.View$PerformClick.run(View.java:17476)
at android.os.Handler.handleCallback(Handler.java:800)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5371)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Whenever I click the button on my first fragment, my app crashes. What the hell is the problem?
解决方案 You could use Intents (register broadcast receiver in fragment B and send broadcasts from fragment A. Use EventBus: https://github.com/greenrobot/EventBus. It's my favorite approach. Very convinient to use, easy communications between any components (Activity & Services, for example).Steps to do:
First, create some class to represent event when your text changes:
public class TextChangedEvent {
public String newText;
public TextChangedEvent(String newText) {
this.newText = newText;
}
}
Then, in fragment A:
//when text changes
EventBus bus = EventBus.getDefault();
bus.post(new TextChangedEvent(newText));
in fragment B:
EventBus bus = EventBus.getDefault();
//Register to EventBus
@Override
public void onCreate(SavedInstanceState savedState) {
bus.register(this);
}
//catch Event from fragment A
public void onEvent(TextChangedEvent event) {
yourTextView.setText(event.newText);
}
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