我正在使用Android中的“TabHost”小部件来解决我的第一个应用程序。
我已将XML布局定义为：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginRight="5dp"
android:orientation="horizontal"
tools:context=".fragments.ConditionsDialogFragment" >
<TextView
android:id="@+id/name_banner"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/rounded_corner_button"
android:text="ddddd"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="#ffffff" />
<TextView
android:id="@+id/name_lbl0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/name_banner"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
android:text="Display Prompts"
android:textAppearance="?android:attr/textAppearanceMedium" />
<View
android:id="@+id/firstDivider"
android:layout_width="fill_parent"
android:layout_height="2dp"
android:layout_below="@id/name_lbl0"
android:layout_marginBottom="3dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_marginTop="3dp"
android:background="#BFBDBE" />
<TextView
android:id="@+id/name_lbl1"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_below="@+id/firstDivider"
android:layout_marginLeft="10dp"
android:layout_marginTop="3dp"
android:gravity="right"
android:text="Order Placer :"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/cond_c01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/firstDivider"
android:layout_marginLeft="10dp"
android:layout_marginTop="3dp"
android:layout_toRightOf="@+id/name_lbl1"
android:text="XXXX"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/name_lbl2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/name_lbl1"
android:layout_below="@+id/name_lbl1"
android:text="Specimen Taker :"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/cond_c02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/name_lbl1"
android:layout_marginLeft="10dp"
android:layout_toRightOf="@+id/name_lbl2"
android:text="XXXX"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_marginBottom="15dp"
android:layout_marginRight="10dp"
android:text="OK" />
<TabHost
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/button1"
android:layout_alignLeft="@+id/name_lbl1"
android:layout_below="@+id/cond_c02"
android:layout_marginTop="6dp" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TabWidget
android:id="@android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</TabWidget>
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="@+id/tab1"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</LinearLayout>
<LinearLayout
android:id="@+id/tab2"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</LinearLayout>
<LinearLayout
android:id="@+id/tab3"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</LinearLayout>
</FrameLayout>
</LinearLayout>
</TabHost>
</RelativeLayout>
布局在DialogFragment中使用，代码如下：
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View thisView = inflater.inflate(R.layout.nlmc_conditions, container, false);
TextView bannerName = (TextView)thisView.findViewById(R.id.name_banner);
TextView c01 = (TextView)thisView.findViewById(R.id.cond_c01);
TextView c02 = (TextView)thisView.findViewById(R.id.cond_c02);
c01.setText(cursor.getString(cursor.getColumnIndex("CHOICEORDERDISPLAY")));
c02.setText(cursor.getString(cursor.getColumnIndex("CHOICETAKERDISPLAY")));
TabHost tabHost = (TabHost)thisView.findViewById(android.R.id.tabhost);
TabSpec ts = tabHost.newTabSpec("tag1");
ts.setContent(R.id.tab1);
ts.setIndicator("Tab one");
tabHost.addTab(ts);
bannerName.setText(conditions.Specimen + " specimen preconditions");
return thisView;
}
当它运行时，屏幕不显示且应用程序失败，日志在此处：
03-20 13:35:48.129: E/AndroidRuntime(17149): FATAL EXCEPTION: main
03-20 13:35:48.129: E/AndroidRuntime(17149): java.lang.NullPointerException
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.widget.TabHost$ViewIdContentStrategy.<init>(TabHost.java:629)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.widget.TabHost$ViewIdContentStrategy.<init>(TabHost.java:624)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.widget.TabHost$TabSpec.setContent(TabHost.java:473)
03-20 13:35:48.129: E/AndroidRuntime(17149): at com.apps4care.nlmcbrowser.fragments.ConditionsDialogFragment.onCreateView(ConditionsDialogFragment.java:69)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.os.Handler.handleCallback(Handler.java:615)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.os.Handler.dispatchMessage(Handler.java:92)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.os.Looper.loop(Looper.java:137)
03-20 13:35:48.129: E/AndroidRuntime(17149): at android.app.ActivityThread.main(ActivityThread.java:4745)
03-20 13:35:48.129: E/AndroidRuntime(17149): at java.lang.reflect.Method.invokeNative(Native Method)
03-20 13:35:48.129: E/AndroidRuntime(17149): at java.lang.reflect.Method.invoke(Method.java:511)
03-20 13:35:48.129: E/AndroidRuntime(17149): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
03-20 13:35:48.129: E/AndroidRuntime(17149): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-20 13:35:48.129: E/AndroidRuntime(17149): at dalvik.system.NativeStart.main(Native Method)
03-20 13:40:48.179: I/Process(17149): Sending signal. PID: 17149 SIG: 9
任何帮助表示赞赏
答案 0 :(得分：1)
为了其他人的利益，我发现了这个问题。
在使用TabHost类之前，我忘了添加以下内容。
tabHost.setup();