Android 在片段选项卡中插入listview后应用程序崩溃
我找到了一个代码来实现带有片段的tab。我试图将listview放入片段中,但应用程序因以下错误而崩溃。你能看一下密码并给我指路吗。多谢各位Android 在片段选项卡中插入listview后应用程序崩溃,android,android-listview,android-fragmentactivity,Android,Android Listview,Android Fragmentactivity,我找到了一个代码来实现带有片段的tab。我试图将listview放入片段中,但应用程序因以下错误而崩溃。你能看一下密码并给我指路吗。多谢各位 01-18 11:44:49.130: E/AndroidRuntime(1908): FATAL EXCEPTION: main 01-18 11:44:49.130: E/AndroidRuntime(1908): java.lang.RuntimeException: Unable to start activity ComponentInfo{co
01-18 11:44:49.130: E/AndroidRuntime(1908): FATAL EXCEPTION: main
01-18 11:44:49.130: E/AndroidRuntime(1908): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.abe/com.example.abe.TabsFragmentActivity}: java.lang.NullPointerException
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread.access$600(ActivityThread.java:130)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.os.Handler.dispatchMessage(Handler.java:99)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.os.Looper.loop(Looper.java:137)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread.main(ActivityThread.java:4745)
01-18 11:44:49.130: E/AndroidRuntime(1908): at java.lang.reflect.Method.invokeNative(Native Method)
01-18 11:44:49.130: E/AndroidRuntime(1908): at java.lang.reflect.Method.invoke(Method.java:511)
01-18 11:44:49.130: E/AndroidRuntime(1908): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
01-18 11:44:49.130: E/AndroidRuntime(1908): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-18 11:44:49.130: E/AndroidRuntime(1908): at dalvik.system.NativeStart.main(Native Method)
01-18 11:44:49.130: E/AndroidRuntime(1908): Caused by: java.lang.NullPointerException
01-18 11:44:49.130: E/AndroidRuntime(1908): at com.example.abe.Tab1Fragment.onCreateView(Tab1Fragment.java:44)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1070)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1861)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:547)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1163)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.Activity.performStart(Activity.java:5018)
01-18 11:44:49.130: E/AndroidRuntime(1908): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2032)
01-18 11:44:49.130: E/AndroidRuntime(1908): ... 11 more
TABFRAGMENTACTIVITY类:
import java.util.HashMap;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.widget.TabHost;
import android.widget.TabHost.TabContentFactory;
public class TabsFragmentActivity extends FragmentActivity implements TabHost.OnTabChangeListener {
private TabHost mTabHost;
private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, TabsFragmentActivity.TabInfo>();
private TabInfo mLastTab = null;
private class TabInfo {
private String tag;
private Class<?> clss;
private Bundle args;
private Fragment fragment;
TabInfo(String tag, Class<?> clazz, Bundle args) {
this.tag = tag;
this.clss = clazz;
this.args = args;
}
}
class TabFactory implements TabContentFactory {
private final Context mContext;
public TabFactory(Context context)
{
mContext = context;
}
public View createTabContent(String tag)
{
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabs_layout);
initialiseTabHost(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); //set the tab as per the saved state
}
}
protected void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); //save the tab selected
super.onSaveInstanceState(outState);
}
private void initialiseTabHost(Bundle args) {
mTabHost = (TabHost)findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
TabsFragmentActivity.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab1").setIndicator("Tab 1"), ( tabInfo = new TabInfo("Tab1", Tab1Fragment.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsFragmentActivity.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab2").setIndicator("Tab 2"), ( tabInfo = new TabInfo("Tab2", Tab2Fragment.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsFragmentActivity.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab 3"), ( tabInfo = new TabInfo("Tab3", Tab3Fragment.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
this.onTabChanged("Tab1");
mTabHost.setOnTabChangedListener(this);
}
private static void addTab(TabsFragmentActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) {
tabSpec.setContent(activity.new TabFactory(activity));
String tag = tabSpec.getTag();
tabInfo.fragment = activity.getSupportFragmentManager().findFragmentByTag(tag);
if (tabInfo.fragment != null && !tabInfo.fragment.isDetached()) {
FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction();
ft.detach(tabInfo.fragment);
ft.commit();
activity.getSupportFragmentManager().executePendingTransactions();
}
tabHost.addTab(tabSpec);
}
public void onTabChanged(String tag) {
TabInfo newTab = this.mapTabInfo.get(tag);
if (mLastTab != newTab) {
FragmentTransaction ft = this.getSupportFragmentManager().beginTransaction();
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(this,
newTab.clss.getName(), newTab.args);
ft.add(R.id.realtabcontent, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
ft.commit();
this.getSupportFragmentManager().executePendingTransactions();
}
}
}
import java.util.HashMap;
导入android.content.Context;
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.support.v4.app.FragmentActivity;
导入android.support.v4.app.FragmentTransaction;
导入android.view.view;
导入android.widget.TabHost;
导入android.widget.TabHost.TabContentFactory;
公共类TabsFragmentActivity扩展FragmentActivity实现TabHost.OnTabChangeListener{
私有TabHost-mTabHost;
私有HashMap mapTabInfo=新HashMap();
private TabInfo mLastTab=null;
私有类TabInfo{
私有字符串标签;
私家级CLS;
私有包args;
私有片段;
TabInfo(字符串标记、类clazz、包参数){
this.tag=tag;
this.clss=clazz;
this.args=args;
}
}
类TabFactory实现TabContentFactory{
私有最终上下文mContext;
公共选项卡工厂(上下文)
{
mContext=上下文;
}
公共视图createTabContent(字符串标记)
{
视图v=新视图(mContext);
v、 设置最小宽度(0);
v、 设置最小高度(0);
返回v;
}
}
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.tabs\u布局);
initialiseTabHost(savedInstanceState);
如果(savedInstanceState!=null){
mTabHost.setCurrentTabByTag(savedInstanceState.getString(“tab”);//根据保存的状态设置选项卡
}
}
SaveInstanceState上受保护的无效(束超出状态){
outState.putString(“tab”,mTabHost.getCurrentTabTag());//保存选定的选项卡
super.onSaveInstanceState(超出状态);
}
私有void initialiseTabHost(Bundle args){
mTabHost=(TabHost)findViewById(android.R.id.TabHost);
mTabHost.setup();
TabInfo TabInfo=null;
TabsFragmentActivity.addTab(this,this.mTabHost,this.mTabHost.newTabSpec(“Tab1”).setIndicator(“Tab1”),(tabInfo=new tabInfo(“Tab1”,Tab1Fragment.class,args));
this.mapTabInfo.put(tabInfo.tag,tabInfo);
TabsFragmentActivity.addTab(this,this.mTabHost,this.mTabHost.newTabSpec(“Tab2”).setIndicator(“Tab2”),(tabInfo=new tabInfo(“Tab2”,Tab2Fragment.class,args));
this.mapTabInfo.put(tabInfo.tag,tabInfo);
TabsFragmentActivity.addTab(this,this.mTabHost,this.mTabHost.newTabSpec(“Tab3”).setIndicator(“Tab3”),(tabInfo=new tabInfo(“Tab3”,Tab3Fragment.class,args));
this.mapTabInfo.put(tabInfo.tag,tabInfo);
本表已更改(“表1”);
mTabHost.setOnTabChangedListener(此);
}
私有静态void addTab(TabsFragmentActivity活动,TabHost TabHost,TabHost.TabSpec TabSpec,TabInfo TabInfo){
tabSpec.setContent(activity.new TabFactory(activity));
String tag=tabSpec.getTag();
tabInfo.fragment=activity.getSupportFragmentManager().findFragmentByTag(标记);
if(tabInfo.fragment!=null&&!tabInfo.fragment.isDetached()){
FragmentTransaction ft=activity.getSupportFragmentManager().beginTransaction();
ft.detach(tabInfo.fragment);
ft.commit();
activity.getSupportFragmentManager().executePendingTransactions();
}
tabHost.addTab(tabSpec);
}
已更改的公用void onTabChanged(字符串标记){
TabInfo newTab=this.mapTabInfo.get(标记);
如果(mLastTab!=newTab){
FragmentTransaction ft=this.getSupportFragmentManager().beginTransaction();
如果(mLastTab!=null){
if(mLastTab.fragment!=null){
ft.分离(mLastTab.碎片);
}
}
if(newTab!=null){
if(newTab.fragment==null){
newTab.fragment=fragment.instantiate(这个,
newTab.clss.getName(),newTab.args);
ft.add(R.id.realtabcontent,newTab.fragment,newTab.tag);
}否则{
ft.attach(newTab.fragment);
}
}
mLastTab=newTab;
ft.commit();
此.getSupportFragmentManager().executePendingTransactions();
}
}
}
TABFRAGMENT类-这是我试图放置listview的地方:
import android.annotation.TargetApi;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
public class Tab1Fragment extends ListFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ListView lv = (ListView)getView().findViewById(R.id.listView1);
String android_array1[] = new String[50];
for(int i=0;i<50;i++)
{
android_array1[i]="ab"+i;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity().getBaseContext(), android.R.layout.simple_list_item_1, android_array1);
lv.setAdapter(adapter);
return (LinearLayout)inflater.inflate(R.layout.tab_frag1_layout, container, false);
}
}
导入android.annotation.TargetApi;
导入android.os.Build;
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.support.v4.app.ListFragment;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ArrayAdapter;
导入android.widget.LinearLayout;
导入android.widget.ListView;
公共类Tab1Fragment扩展了ListFragment{
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
ListView lv=(ListView)getView().findViewById(R.id.listView1);
字符串android_array1[]=新字符串[50];
对于(int i=0;i注:
如果在选项卡1片段中扩展列表片段
那就不用用了
ListView lv=(ListView)root.findviewbyd(R.id.listView1);
把它拿走
最后,您的onCreateView(..)
方法如下所示:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
String android_array1[] = new String[50];
for(int i=0;i<50;i++)
{
android_array1[i]="ab"+i;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity().getBaseContext(), android.R.layout.simple_list_item_1, android_array1);
setListAdapter(adapter);
return super.onCreateView(inflater, container, savedInstanceState);
}
@覆盖
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
字符串android_array1[]=新字符串[50];
对于(int i=0;i注:
如果在选项卡1片段中扩展列表片段
那就不用用了
ListView lv=(ListView)root.findviewbyd(R.id.listView1);
把它拿走
最后,您的onCreateView(..)
方法如下所示:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
String android_array1[] = new String[50];
for(int i=0;i<50;i++)
{
android_array1[i]="ab"+i;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity().getBaseContext(), android.R.layout.simple_list_item_1, android_array1);
setListAdapter(adapter);
return super.onCreateView(inflater, container, savedInstanceState);
}
@覆盖
创建视图上的公共视图(布局、充气机、视图组)