我正在尝试创建一个滑动标签布局，并且已将两级列表视图的代码导入到应用程序中。在构建它之后试图使应用程序工作一周后，只需构建两级列表视图，而不在顶部使用滑动选项卡布局。我只是这样做了大约一个月所以我真的不了解logcat输出所以我找不到问题所在。如果有人能帮助我，我将不胜感激。我的代码可能存在问题，所以我已将所有文件发布在这里。
logcat的
03-09 12:32:40.801: I/Process(1026): Sending signal. PID: 1026 SIG: 9
03-09 12:34:23.966: D/dalvikvm(1081): GC_FOR_ALLOC freed 77K, 8% free 2559K/2756K, paused 28ms, total 32ms
03-09 12:34:23.966: I/dalvikvm-heap(1081): Grow heap (frag case) to 3.220MB for 635812-byte allocation
03-09 12:34:24.006: D/dalvikvm(1081): GC_FOR_ALLOC freed 2K, 6% free 3177K/3380K, paused 39ms, total 39ms
03-09 12:34:24.066: D/dalvikvm(1081): GC_CONCURRENT freed 9K, 6% free 3198K/3380K, paused 7ms+14ms, total 53ms
03-09 12:34:24.176: D/AndroidRuntime(1081): Shutting down VM
03-09 12:34:24.176: W/dalvikvm(1081): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
03-09 12:34:24.196: E/AndroidRuntime(1081): FATAL EXCEPTION: main
03-09 12:34:24.196: E/AndroidRuntime(1081): java.lang.ClassCastException: com.learn2crack.tab.MainActivity@40ce7420 must implement OnHeadlineSelectedListener
03-09 12:34:24.196: E/AndroidRuntime(1081): at com.learn2crack.tab.HeadlinesFragment.onAttach(HeadlinesFragment.java:68)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:883)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.app.FragmentManagerImpl.performPendingDeferredStart(FragmentManager.java:823)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.app.Fragment.setUserVisibleHint(Fragment.java:841)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.app.FragmentStatePagerAdapter.setPrimaryItem(FragmentStatePagerAdapter.java:152)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.view.ViewPager.populate(ViewPager.java:1066)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.View.measure(View.java:15518)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.View.measure(View.java:15518)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.View.measure(View.java:15518)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
03-09 12:34:24.196: E/AndroidRuntime(1081): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2176)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.View.measure(View.java:15518)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.Choreographer.doFrame(Choreographer.java:532)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.os.Handler.handleCallback(Handler.java:725)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.os.Handler.dispatchMessage(Handler.java:92)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.os.Looper.loop(Looper.java:137)
03-09 12:34:24.196: E/AndroidRuntime(1081): at android.app.ActivityThread.main(ActivityThread.java:5041)
03-09 12:34:24.196: E/AndroidRuntime(1081): at java.lang.reflect.Method.invokeNative(Native Method)
03-09 12:34:24.196: E/AndroidRuntime(1081): at java.lang.reflect.Method.invoke(Method.java:511)
03-09 12:34:24.196: E/AndroidRuntime(1081): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-09 12:34:24.196: E/AndroidRuntime(1081): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-09 12:34:24.196: E/AndroidRuntime(1081): at dalvik.system.NativeStart.main(Native Method)
ArticleFragment.java
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.learn2crack.tab;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class ArticleFragment extends Fragment {
final static String ARG_POSITION = "position";
int mCurrentPosition = -1;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// If activity recreated (such as from screen rotate), restore
// the previous article selection set by onSaveInstanceState().
// This is primarily necessary when in the two-pane layout.
if (savedInstanceState != null) {
mCurrentPosition = savedInstanceState.getInt(ARG_POSITION);
}
// Inflate the layout for this fragment
return inflater.inflate(R.layout.article_view, container, false);
}
@Override
public void onStart() {
super.onStart();
// During startup, check if there are arguments passed to the fragment.
// onStart is a good place to do this because the layout has already been
// applied to the fragment at this point so we can safely call the method
// below that sets the article text.
Bundle args = getArguments();
if (args != null) {
// Set article based on argument passed in
updateArticleView(args.getInt(ARG_POSITION));
} else if (mCurrentPosition != -1) {
// Set article based on saved instance state defined during onCreateView
updateArticleView(mCurrentPosition);
}
}
public void updateArticleView(int position) {
TextView article = (TextView) getActivity().findViewById(R.id.article);
article.setText(Ipsum.Articles[position]);
mCurrentPosition = position;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save the current article selection in case we need to recreate the fragment
outState.putInt(ARG_POSITION, mCurrentPosition);
}
}
HeadlinesFragment.java
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.learn2crack.tab;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class HeadlinesFragment extends ListFragment {
OnHeadlineSelectedListener mCallback;
// The container Activity must implement this interface so the frag can deliver messages
public interface OnHeadlineSelectedListener {
/** Called by HeadlinesFragment when a list item is selected */
public void onArticleSelected(int position);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// We need to use a different list item layout for devices older than Honeycomb
int layout = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ?
android.R.layout.simple_list_item_activated_1 : android.R.layout.simple_list_item_1;
// Create an array adapter for the list view, using the Ipsum headlines array
setListAdapter(new ArrayAdapter<String>(getActivity(), layout, Ipsum.Headlines));
}
@Override
public void onStart() {
super.onStart();
// When in two-pane layout, set the listview to highlight the selected list item
// (We do this during onStart because at the point the listview is available.)
if (getFragmentManager().findFragmentById(R.id.article_fragment) != null) {
getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
}
}
@Override
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 = (OnHeadlineSelectedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnHeadlineSelectedListener");
}
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// Notify the parent activity of selected item
mCallback.onArticleSelected(position);
// Set the item as checked to be highlighted when in two-pane layout
getListView().setItemChecked(position, true);
}
}
MainActivity.java
package com.learn2crack.tab;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity {
ViewPager Tab;
TabPagerAdapter TabAdapter;
ActionBar actionBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TabAdapter = new TabPagerAdapter(getSupportFragmentManager());
Tab = (ViewPager)findViewById(R.id.pager);
Tab.setOnPageChangeListener(
new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar = getActionBar();
actionBar.setSelectedNavigationItem(position); }
});
Tab.setAdapter(TabAdapter);
actionBar = getActionBar();
//Enable Tabs on Action Bar
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.TabListener tabListener = new ActionBar.TabListener(){
@Override
public void onTabReselected(android.app.ActionBar.Tab tab,
FragmentTransaction ft) {
// TODO Auto-generated method stub
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
Tab.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(android.app.ActionBar.Tab tab,
FragmentTransaction ft) {
// TODO Auto-generated method stub
}};
//Add New Tab
actionBar.addTab(actionBar.newTab().setText("Android").setTabListener(tabListener));
actionBar.addTab(actionBar.newTab().setText("iOS").setTabListener(tabListener));
actionBar.addTab(actionBar.newTab().setText("Windows").setTabListener(tabListener));
}
}
SoftwareSearchActivity.java
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.learn2crack.tab;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
interface OnHeadlineSelectedListener {
/** Called by HeadlinesFragment when a list item is selected */
public void onArticleSelected(int position);
}
public class SoftWareSearchActivity extends FragmentActivity
implements HeadlinesFragment.OnHeadlineSelectedListener {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news_articles);
// Check whether the activity is using the layout version with
// the fragment_container FrameLayout. If so, we must add the first fragment
if (findViewById(R.id.fragment_container) != null) {
// However, if we're being restored from a previous state,
// then we don't need to do anything and should return or else
// we could end up with overlapping fragments.
if (savedInstanceState != null) {
return;
}
// Create an instance of ExampleFragment
HeadlinesFragment firstFragment = new HeadlinesFragment();
// In case this activity was started with special instructions from an Intent,
// pass the Intent's extras to the fragment as arguments
firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, firstFragment).commit();
}
}
public void onArticleSelected(int position) {
// The user selected the headline of an article from the HeadlinesFragment
// Capture the article fragment from the activity layout
ArticleFragment articleFrag = (ArticleFragment)
getSupportFragmentManager().findFragmentById(R.id.article_fragment);
if (articleFrag != null) {
// If article frag is available, we're in two-pane layout...
// Call a method in the ArticleFragment to update its content
articleFrag.updateArticleView(position);
} else {
// If the frag is not available, we're in the one-pane layout and must swap frags...
// Create fragment and give it an argument for the selected article
ArticleFragment newFragment = new ArticleFragment();
Bundle args = new Bundle();
args.putInt(ArticleFragment.ARG_POSITION, position);
newFragment.setArguments(args);
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack so the user can navigate back
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
}
}
TabPagerAdapter.java
package com.learn2crack.tab;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class TabPagerAdapter extends FragmentStatePagerAdapter {
public TabPagerAdapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
@Override
public Fragment getItem(int i) {
switch (i) {
case 0:
//Fragement for Android Tab
return new HeadlinesFragment();
case 1:
//Fragment for Ios Tab
return new Windows();
case 2:
//Fragment for Windows Tab
return new Windows();
}
return null;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return 3; //No of Tabs
}
}
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
article_view.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/article"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:textSize="18sp" />
news_article.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
</LinearLayout>
布局 - 大文件夹
new_articles.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment android:name="com.example.android.fragments.HeadlinesFragment"
android:id="@+id/headlines_fragment"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
<fragment android:name="com.example.android.fragments.ArticleFragment"
android:id="@+id/article_fragment"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.learn2crack.tab"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<!-- The following two permissions are not required to use
Google Maps Android API v2, but are recommended. -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.learn2crack.tab.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.android.maps.v2.AIzaSyDtQiCXQAlaNJTjyxy-gHqSg7ROD4tm8hQ"
android:value="AIzaSyDtQiCXQAlaNJTjyxy-gHqSg7ROD4tm8hQ"/>
</application>
</manifest>
答案 0 :(得分：0)
您的主要活动：
public class MainActivity extends FragmentActivity { //..
必须实现OnHeadlineSelectedListener：
public class MainActivity extends FragmentActivity implements HeadlinesFragment.OnHeadlineSelectedListener { //..
因为你的onAttach方法在这里：
mCallback = (OnHeadlineSelectedListener) activity;
您正尝试将其投放到OnHeadlineSelectedListener
另请参阅android文档的链接：http://developer.android.com/training/basics/fragments/communicating.html#Implement
public static class MainActivity extends FragmentActivity
implements HeadlinesFragment.OnHeadlineSelectedListener{
//your other activity code here...
public void onArticleSelected(int position) {
// The user selected the headline of an article from the HeadlinesFragment
// Do something here to display that article
}
}