Java Android:在片段之间传递对象
在开始之前,我已经仔细研究了以下问题: 以及Android文档: 除了这篇文章: 虽然上面提到的所有案例都与我的相似,但并不完全相同。我在这里遵循了一个很好的教程(我的部分代码基于本文): 我有以下文件: RegisterActivity.javaJava Android:在片段之间传递对象,java,android,android-fragments,Java,Android,Android Fragments,在开始之前,我已经仔细研究了以下问题: 以及Android文档: 除了这篇文章: 虽然上面提到的所有案例都与我的相似,但并不完全相同。我在这里遵循了一个很好的教程(我的部分代码基于本文): 我有以下文件: RegisterActivity.java NonSwipeableViewPager.java ScreenSliderAdapter.java RegisterOneFragment.java registerwofragment.java 以及以下布局: 活动\u regist
NonSwipeableViewPager.java
ScreenSliderAdapter.java
RegisterOneFragment.java
registerwofragment.java 以及以下布局: 活动\u register.xml
fragment\u register\u one.xml
fragment\u register\u two.xml 我试图实现的是将一个可序列化对象从RegisterFragmentOne传递到RegisterFragmentTwo 到目前为止,这就是我所做的(省略了一些代码): RegisterActivity.java
public class RegisterActivity extends FragmentActivity
implements RegisterOneFragment.OnEmailRegisteredListener{
public static NonSwipeableViewPager viewPager;
private ScreenSliderAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
// Initilization
mAdapter = new ScreenSliderAdapter(getSupportFragmentManager());
viewPager = (NonSwipeableViewPager) findViewById(R.id.pager);
viewPager.setAdapter(mAdapter);
}
public void onEmailRegistered(int position, Registration regData){
Bundle args = new Bundle();
args.putSerializable("regData", regData);
viewPager.setCurrentItem(position, true);
}
}
public class ScreenSliderAdapter extends FragmentPagerAdapter{
public ScreenSliderAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new RegisterOneFragment();
case 1:
return new RegisterTwoFragment();
case 2:
return new RegisterThreeFragment();
}
return null;
}
@Override
public int getCount() {
return 3;
}
}
public class RegisterOneFragment extends Fragment {
OnEmailRegisteredListener mCallBack;
public interface OnEmailRegisteredListener {
/** Called by RegisterOneFragment when an email is registered */
public void onEmailRegistered(int position, Registration regData);
}
public void onAttach(Activity activity){
super.onAttach(activity);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception.
try {
mCallBack = (OnEmailRegisteredListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnEmailRegisteredListener");
}
}
... And some to execute some HTTP request via separate thread...
}
ScreenSliderAdapter.java
public class RegisterActivity extends FragmentActivity
implements RegisterOneFragment.OnEmailRegisteredListener{
public static NonSwipeableViewPager viewPager;
private ScreenSliderAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
// Initilization
mAdapter = new ScreenSliderAdapter(getSupportFragmentManager());
viewPager = (NonSwipeableViewPager) findViewById(R.id.pager);
viewPager.setAdapter(mAdapter);
}
public void onEmailRegistered(int position, Registration regData){
Bundle args = new Bundle();
args.putSerializable("regData", regData);
viewPager.setCurrentItem(position, true);
}
}
public class ScreenSliderAdapter extends FragmentPagerAdapter{
public ScreenSliderAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new RegisterOneFragment();
case 1:
return new RegisterTwoFragment();
case 2:
return new RegisterThreeFragment();
}
return null;
}
@Override
public int getCount() {
return 3;
}
}
public class RegisterOneFragment extends Fragment {
OnEmailRegisteredListener mCallBack;
public interface OnEmailRegisteredListener {
/** Called by RegisterOneFragment when an email is registered */
public void onEmailRegistered(int position, Registration regData);
}
public void onAttach(Activity activity){
super.onAttach(activity);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception.
try {
mCallBack = (OnEmailRegisteredListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnEmailRegisteredListener");
}
}
... And some to execute some HTTP request via separate thread...
}
NonSwipeableViewPager.java(扩展ViewPager类,并覆盖以下内容)
RegisterOneFragment.java
public class RegisterActivity extends FragmentActivity
implements RegisterOneFragment.OnEmailRegisteredListener{
public static NonSwipeableViewPager viewPager;
private ScreenSliderAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
// Initilization
mAdapter = new ScreenSliderAdapter(getSupportFragmentManager());
viewPager = (NonSwipeableViewPager) findViewById(R.id.pager);
viewPager.setAdapter(mAdapter);
}
public void onEmailRegistered(int position, Registration regData){
Bundle args = new Bundle();
args.putSerializable("regData", regData);
viewPager.setCurrentItem(position, true);
}
}
public class ScreenSliderAdapter extends FragmentPagerAdapter{
public ScreenSliderAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new RegisterOneFragment();
case 1:
return new RegisterTwoFragment();
case 2:
return new RegisterThreeFragment();
}
return null;
}
@Override
public int getCount() {
return 3;
}
}
public class RegisterOneFragment extends Fragment {
OnEmailRegisteredListener mCallBack;
public interface OnEmailRegisteredListener {
/** Called by RegisterOneFragment when an email is registered */
public void onEmailRegistered(int position, Registration regData);
}
public void onAttach(Activity activity){
super.onAttach(activity);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception.
try {
mCallBack = (OnEmailRegisteredListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnEmailRegisteredListener");
}
}
... And some to execute some HTTP request via separate thread...
}
我试图实现的是,当用户按下RegisterOnFragment上的按钮时,数据将被发送到服务器(并通过JSON返回一些验证)。如果返回的数据有效,应用程序应该转到下一个片段,即RegistrationTwoFragment
对于如何在片段之间传递对象,我感到有些困惑,因为我的片段是使用适配器创建的。然后,该适配器连接到我的活动
有人能帮我吗?Thx
编辑1:
我试着做一个这样的捷径(不幸的是不起作用):
在我创建的RegisterActivity中:
public Registration regData;
在本节中:
/* PLACED ON POST EXECUTE */
((RegisterActivity)getActivity()).regData = regData;
最后在RegisterWoFragment中调用了它
Registration regData;
regData = ((RegisterActivity) getActivity()).regData;
它抛出一个nullPointerExceptions
编辑2
需要明确的是,RegisterActivity包含多个片段。用户在片段之间导航的唯一方法是单击按钮。该活动没有选项卡栏。我通常会在包含该活动的过程中使用类似的设置器或方法 因此,如果我理解正确,您希望用户访问
RegistrationOneFragment
,然后在完成后,使用此数据,验证它,如果有效,将其传递给RegistrationTwoFragment
,并将用户移动到此Fragment
您是否可以在onEmailRegistered
方法中调用validateJson(regData)
来处理活动中的验证,如果成功,请将事务提交到RegistrationTwoFragment
然后,您只需要在活动或片段中使用getter和setter,在活动中使用getRegistrationOneData()
,或在片段中使用setData(注册参数)
,如上面的示例所示
我不知道如何将args直接传递到片段中。我找到了我的问题的解决方案,我确信这不是正确的方法 因此,在RegisterActivity.java中,我添加并修改了以下几行(thx到@sturrockad): 然后在RegisterWoFragments.java中(或在我想要接收对象的片段中):
通过对自定义对象实现可序列化,可以很容易地共享对象。我写了一篇关于这个的教程 从片段一开始:
android.support.v4.app.FragmentTransaction ft =
getActivity().getSupportFragmentManager().beginTransaction();
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
OfficeCategoryFragment frag = new OfficeCategoryFragment();
Bundle bundles = new Bundle();
Division aDivision = divisionList.get(position);
// ensure your object has not null
if (aDivision != null) {
bundles.putSerializable("aDivision", aDivision);
Log.e("aDivision", "is valid");
} else {
Log.e("aDivision", "is null");
}
frag.setArguments(bundles);
ft.replace(android.R.id.content, frag);
ft.addToBackStack(null);
ft.commit();
第二部分:
Bundle bundle = getArguments();
Division division= (Division) bundle.getSerializable("aDivision");
Log.e("division TEST", "" + division.getName());
我过去常常将对象设置为PaceAble或Serializable以进行传输,但每当我向对象(模型)添加其他变量时,我都必须将其全部注册。太不方便了 在活动或片段之间传输对象非常容易
User userItem = new User(1, "KimKevin"); // Sample Model
KimchiDataCache.getInstance().put(userItem);
// add your activity or fragment
public class MainFragment extends Fragment{
private User userItem;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
userItem = KimchiDataCache.getInstance().get(User.class);
}
是的,这正是我试图用我的代码做的。关于您的解决方案,这是否意味着我不必使用适配器?同时,我会尽量听从你的建议。Thx…如果您想保留寻呼机和适配器,那么您应该保留它,但我认为您也可以使用supportFragmentManager()和事务轻松处理它。我想您是对的,只是我正在尽可能少的努力来完成这项工作…很高兴提供帮助。如果您对get()方法解决方案感到满意,请接受答案。这具有singleton模式的行为,这是一种非常反模式,它的痛苦在于单元测试。对于尝试以较少的努力完成类似操作的人:使用google gson将pojo序列化为json,并将其与捆绑包一起发送(setArguments)。对于试图以较少的努力完成类似工作的人:使用google gson将pojo序列化为json,并将其与捆绑包一起发送。这更好,因为您不需要为每个对象实现可序列化,并且当您更改对象属性(在后端)时,您不需要更改可序列化的实现。您能告诉我们