您好我正在尝试将意图传递给FragmentActivity，但它无效。活动在FragmentActivity的初始化中关闭。这是活动：
public class ProcuraPontoActivity extends Activity implements OnClickListener, OnItemClickListener {
/** EditText da procura do ponto. Geralmente o input é o ID ou nome do ponto */
private EditText procura;
/** ListView que mostra todos os pontos encontrados */
private ListView lv;
/** DAO do Ponto para procurar pontos */
private PontoDAO dao;
/** ArrayList de Pontos encontrados */
private ArrayList<Ponto> AL = null;
/** ArrayList que vai pegar a ID do ponto encontrado com o nome do Ponto para mostrar na lv */
private ArrayList<HashMap<String,String>> lista;
/** Adaptador utilizado */
private SimpleAdapter adapter;
/** O usuário atual */
private Usuario user;
/**
* Inicia a activity de procura de pontos.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.procura_ponto);
lista = new ArrayList<HashMap<String,String>>();
AL = new ArrayList<Ponto>();
user = Usuario.toUser(getIntent().getBundleExtra("user"));
/*
* Widgets
*/
procura = (EditText) findViewById(R.id.procura_ponto_et);
Button achar = (Button) findViewById(R.id.procura_ponto_achar);
TextView ppSigla = (TextView) findViewById(R.id.ppSigla);
ppSigla.setText(user.getSigla());
achar.setOnClickListener(this);
dao = new PontoDAO(this);
/*
* ListView
*/
lv = (ListView) findViewById(R.id.procura_ponto_lv);
String[] from = new String[] { "a", "b"};
int[] to = new int[] { R.id.pp_tv1, R.id.pp_tv2 };
int layout = R.layout.procura_ponto_list;
adapter = new SimpleAdapter(this ,lista, layout, from, to);
lv.setAdapter(adapter);
lv.setOnItemClickListener(this);
}
/**
* Faz a verificação da procura e exibe resultados.
*/
public void onClick(View v) {
if (!(procura.getText().toString().equals(""))) {
lista.clear();
FiltroPonto fp = new FiltroPonto();
fp.setNomePonto(procura.getText().toString());
fp.setValor(1);
AL = dao.procuraPonto(user.getSigla(),fp);
Log.i("ProcuraPontoActivity",
"Número de pontos encontrados: " + AL.size());
for (Ponto p : AL) {
HashMap<String, String> hm = new HashMap<String, String>();
if (p.getIdPonto().equals(null)) {
hm.put("a", user.getSigla()+p.getPontoNome());
} else {
hm.put("a", p.getIdPonto());
}
hm.put("b",
"[UTM] E: [" + p.getUTMEste() + "] N: ["
+ p.getUTMNorte() + "] Fuso: ["
+ p.getUTMFuso() + "]");
lista.add(hm);
}
adapter.notifyDataSetChanged();
}
}
/**
* Método chamado cada vez que um click é feito na listview percorrida
* que vai chamar uma nova intent para iniciar o Ponto (PontoTabActivity)
*/
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
PontoDAO pdao = new PontoDAO(this);
String max = pdao.maxIdPonto(user.getIdUsuario(), user.getSigla());
if (AL.get(arg2).getIdPonto().equals(max)) {
Intent i = new Intent(this, PontoTabActivity.class);
i.putExtra("id", AL.get(arg2).getIdPonto());
i.putExtra("user", getIntent().getBundleExtra("user"));
i.putExtra("cria", 1);
startActivity(i);
finish();
} else {
Intent i2 = new Intent(this, RelatorioPontos.class);
i2.putExtra("id", AL.get(arg2).getIdPonto());
startActivity(i2);
}
}
}
这是RelatorioPontos.class：
public class RelatorioPontos extends FragmentActivity implements TabHost.OnTabChangeListener {
private TabHost mTabHost;
private HashMap mapTabInfo = new HashMap();
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;
/**
* @param context
*/
public TabFactory(Context context) {
mContext = context;
}
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.relatorio_layout);
initialiseTabHost(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
}
}
protected void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); //salva a tabela selecionada
super.onSaveInstanceState(outState);
}
private void initialiseTabHost(Bundle args) {
String id = getIntent().getExtras().getString("id");
args.putString("id", id);
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Dados").setIndicator("Dados"),
(tabInfo = new TabInfo("Dados", DadosPonto.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Analises").setIndicator("Analises"),
(tabInfo = new TabInfo("Analises", AnalisesPonto.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Multimidia").setIndicator("Multimidia"),
(tabInfo = new TabInfo("Multimidia", ArquivosMultimidia.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
}
/**
* @param activity
* @param tabHost
* @param tabSpec
* @param clss
* @param args
*/
private static void addTab(RelatorioPontos 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 = (TabInfo) 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();
}
}
}
这是LogCat：
06-06 11:45:20.661: E/AndroidRuntime(905): java.lang.RuntimeException: Unable to start activity ComponentInfo{caderneta.main.activity/caderneta.main.activity.RelatorioPontos}: java.lang.NullPointerException
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.os.Handler.dispatchMessage(Handler.java:99)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.os.Looper.loop(Looper.java:137)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-06 11:45:20.661: E/AndroidRuntime(905): at java.lang.reflect.Method.invokeNative(Native Method)
06-06 11:45:20.661: E/AndroidRuntime(905): at java.lang.reflect.Method.invoke(Method.java:511)
06-06 11:45:20.661: E/AndroidRuntime(905): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-06 11:45:20.661: E/AndroidRuntime(905): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-06 11:45:20.661: E/AndroidRuntime(905): at dalvik.system.NativeStart.main(Native Method)
06-06 11:45:20.661: E/AndroidRuntime(905): Caused by: java.lang.NullPointerException
06-06 11:45:20.661: E/AndroidRuntime(905): at caderneta.main.activity.RelatorioPontos.initialiseTabHost(RelatorioPontos.java:74)
06-06 11:45:20.661: E/AndroidRuntime(905): at caderneta.main.activity.RelatorioPontos.onCreate(RelatorioPontos.java:61)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.Activity.performCreate(Activity.java:5104)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-06 11:45:20.661: E/AndroidRuntime(905): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
06-06 11:45:20.661: E/AndroidRuntime(905): ... 11 more
答案 0 :(得分：3)
简单：RelatorioPontos #initialise ...参数args为null！首次创建Activity时，bundle savedInstanceState为null。当活动重新创建任何原因（配置更改或返回它）时，savedInstance将不为null。
修改（根据以下评论）： 我没有清楚地了解你的代码应该做什么（这是你的责任）而且它不具有建设性;但我会删除那个参数。
根据目前的实施情况，接近工作的是：
private void initialiseTabHost() {
String id = getIntent().getExtras().getString("id");
Bundle args = new Bundle();
args.putString("id", id);
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Dados").setIndicator("Dados"),
(tabInfo = new TabInfo("Dados", DadosPonto.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Analises").setIndicator("Analises"),
(tabInfo = new TabInfo("Analises", AnalisesPonto.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
RelatorioPontos.addTab(this, this.mTabHost, this.mTabHost.newTabSpec("Multimidia").setIndicator("Multimidia"),
(tabInfo = new TabInfo("Multimidia", ArquivosMultimidia.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
}
答案 1 :(得分：2)
Caused by: java.lang.NullPointerException at initialiseTabHost(RelatorioPontos.java:74) and onCreate(RelatorioPontos.java:61)。
尝试调试代码，您将了解传递的位置和值null