Java Android:在片段交互侦听器上出错
我一直在研究stackoverflow来解决我的问题,并发现了一些不错的东西,但它对我不起作用,或者我看到它太愚蠢了() 我想在一个框架内放置一个片段,所以我创建了它,以此类推。我必须植入一个接口及其方法。我(想)我做到了,但我的应用程序每次都崩溃 *编辑:我的应用程序崩溃,当我调用openHome或OpenRecommendated时,onCreate方法工作,我得到这些错误,但所有内容都正确显示 这是我的代码: MainActivity.javaJava Android:在片段交互侦听器上出错,java,android,android-fragments,interface,fragment,Java,Android,Android Fragments,Interface,Fragment,我一直在研究stackoverflow来解决我的问题,并发现了一些不错的东西,但它对我不起作用,或者我看到它太愚蠢了() 我想在一个框架内放置一个片段,所以我创建了它,以此类推。我必须植入一个接口及其方法。我(想)我做到了,但我的应用程序每次都崩溃 *编辑:我的应用程序崩溃,当我调用openHome或OpenRecommendated时,onCreate方法工作,我得到这些错误,但所有内容都正确显示 这是我的代码: MainActivity.java import android.app.Act
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends Activity implements HomeFragment.OnFragmentInteractionListener, RecommendedFragment.OnFragmentInteractionListener
{
FragmentTransaction fragmentTransaction;
HomeFragment homeFragment;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
homeFragment = new HomeFragment();
getFragmentManager().beginTransaction().add(R.id.mainFrame, homeFragment).commit();
}
protected void openHome(View view)
{
/*Intent homeIntent = new Intent(this, HomeFragment.class);
startActivity(homeIntent);
homeFragment = new HomeFragment();
getFragmentManager().beginTransaction().replace(R.id.mainFrame, homeFragment).commit();*/
System.out.println("Success");
}
public void openRecommended(View view)
{
Intent recommendedIntent = new Intent(this, RecommendedFragment.class);
startActivity(recommendedIntent);
RecommendedFragment recommendedFragment = new RecommendedFragment();
getFragmentManager().beginTransaction().replace(R.id.mainFrame, recommendedFragment).commit();
}
@Override
public void onFragmentInteractionHome(Uri uri)
{
}
@Override
public void onFragmentInteractionRecommended(Uri uri)
{
}
}
HomeFragment.java
import android.app.Activity;
import android.app.Fragment;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {@link Fragment} subclass.
* Activities that contain this fragment must implement the
* {@link HomeFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {@link HomeFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class HomeFragment extends Fragment
{
private OnFragmentInteractionListener mListener;
public static HomeFragment newInstance()
{
HomeFragment fragment = new HomeFragment();
return fragment;
}
public HomeFragment()
{
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home, container, false);
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri)
{
if (mListener != null)
{
mListener.onFragmentInteractionHome(uri);
}
}
@Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
try
{
mListener = (OnFragmentInteractionListener) activity;
}
catch (ClassCastException e)
{
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach()
{
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener
{
// TODO: Update argument type and name
public void onFragmentInteractionHome(Uri uri);
}
}
导入android.app.Activity;
导入android.app.Fragment;
导入android.net.Uri;
导入android.os.Bundle;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
/**
*一个简单的{@link Fragment}子类。
*包含此片段的活动必须实现
*{@link homepragment.OnFragmentInteractionListener}接口
*处理交互事件。
*使用{@link HomeFragment#newInstance}工厂方法
*创建此片段的实例。
*/
公共类HomeFragment扩展了片段
{
私有OnFragmentInteractionListener mListener;
公共静态HomeFragment newInstance()
{
HomeFragment=新的HomeFragment();
返回片段;
}
公共HomeFragment()
{
//必需的空公共构造函数
}
@凌驾
创建时的公共void(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState)
{
//为该碎片膨胀布局
返回充气机。充气(R.layout.fragment_home,容器,假);
}
//TODO:重命名方法、更新参数并将方法挂接到UI事件中
public void onButtonPressed(Uri)
{
if(mListener!=null)
{
onFragmentInteractionHome(uri);
}
}
@凌驾
公共事务主任(活动)
{
超级转速计(活动);
尝试
{
mListener=(OnFragmentInteractionListener)活动;
}
catch(ClassCastException e)
{
抛出新的ClassCastException(activity.toString()
+“必须实现OnFragmentInteractionListener”);
}
}
@凌驾
公共无效连接()
{
super.onDetach();
mListener=null;
}
/**
*此接口必须由包含以下内容的活动实现
*片段,以允许通信此片段中的交互
*该活动以及其中可能包含的其他片段
*活动。
*
*有关更多信息,请参阅Android培训课程。
*/
FragmentInteractionListener上的公共接口
{
//TODO:更新参数类型和名称
公共void onFragmentInteractionHome(Uri);
}
}
RecommendedFragment看起来相同,只是有些方法的名称不同
我总是会遇到这样的错误:
java.lang.RuntimeException:无法启动活动
ComponentInfo{com.domain.app/com.domain.app.MainActivity}:
java.lang.ClassCastException:com.domain.app。MainActivity@b1d296b0
必须实现OnFragmentInteractionListener
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
在android.app.ActivityThread.access$800(ActivityThread.java:135)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)上
位于android.os.Handler.dispatchMessage(Handler.java:102)
位于android.os.Looper.loop(Looper.java:136)
位于android.app.ActivityThread.main(ActivityThread.java:5017)
位于java.lang.reflect.Method.Invokenactive(本机方法)
位于java.lang.reflect.Method.invoke(Method.java:515)
在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)上
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
在dalvik.system.NativeStart.main(本机方法)
原因:java.lang.ClassCastException:com.domain.app。MainActivity@b1d296b0必须实施
OnFragmentInteractionListener
位于com.domain.app.HomeFragment.onAttach(HomeFragment.java:74)
在android.app.FragmentManagerImpl.moveToState(FragmentManager.java:849)
位于android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
运行(BackStackRecord.java:684)
位于android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
位于android.app.Activity.performStart(Activity.java:5240)
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2168)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
在android.app.ActivityThread.access$800(ActivityThread.java:135)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)上
位于android.os.Handler.dispatchMessage(Handler.java:102)
位于android.os.Looper.loop(Looper.java:136)
位于android.app.ActivityThread.main(ActivityThread.java:5017)
位于java.lang.reflect.Method.Invokenactive(本机方法)
位于java.lang.reflect.Method.invoke(Method.java:515)
在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)上
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
a
public class MainActivity extends Activity implements HomeFragment.OnFragmentInteractionListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getFragmentManager().beginTransaction()
.add(R.id.mainFrame, new HomeFragment())
.commit();
}
@Override
public void openHome(View view) {
System.out.println("Success");
}
@Override
public void onFragmentInteractionHome(Uri uri) {
Toast.makeText(this, "Success", Toast.LENGTH_SHORT).show();
}
}
public class HomeFragment extends Fragment {
private OnFragmentInteractionListener mListener;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_home, container, false);
}
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteractionHome(uri);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
mListener.onFragmentInteractionHome(Uri.parse("doWhatYouWant"));
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
public void onFragmentInteractionHome(Uri uri);
public void openHome(View view);
}
}