不能创建选项卡小部件

Question

我从教程学习后尝试创建选项卡视图。但是每当我运行这个应用程序时，它就会崩溃。我把代码写在这里。需要立即帮助

package com.example.androidtablayoutactivity;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;
@SuppressWarnings("deprecation")
public class AndroidTabLayoutActivity extends TabActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TabHost tabHost = getTabHost();
        // Tab for Photos
        TabSpec photospec = tabHost.newTabSpec("Photos");
        // setting Title and Icon for the Tab
        Intent photosIntent = new Intent(this, PhotosActivity.class);
        photospec.setContent(photosIntent);
        // Tab for Songs
        TabSpec songspec = tabHost.newTabSpec("Songs");        
        Intent songsIntent = new Intent(this, SongsActivity.class);
        songspec.setContent(songsIntent);
        // Tab for Videos
        TabSpec videospec = tabHost.newTabSpec("Videos");
        Intent videosIntent = new Intent(this, VideosActivity.class);
        videospec.setContent(videosIntent);
        // Adding all TabSpec to TabHost
        tabHost.addTab(photospec); // Adding photos tab
        tabHost.addTab(songspec); // Adding songs tab
        tabHost.addTab(videospec); // Adding videos tab
    }
}

布局文件= activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"/>
    </LinearLayout>
</TabHost>

SongsActivity.class

package com.example.androidtablayoutactivity;
import android.app.Activity;
import android.os.Bundle;
public class SongsActivity extends Activity {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.songs_layout);
    }
}

songs_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
  <!-- Screen Design for the SONGS -->
  <TextView android:text="SONGS HERE"
            android:padding="15dip"
            android:textSize="18dip"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>
</LinearLayout>

Logcat:

05-23 17:39:52.411: D/ActivityThread(20945): setTargetHeapConcurrentStart:2097152
05-23 17:39:52.741: D/AndroidRuntime(20945): Shutting down VM
05-23 17:39:52.761: W/dalvikvm(20945): threadid=1: thread exiting with uncaught exception (group=0x41744438)
05-23 17:39:52.781: E/AndroidRuntime(20945): FATAL EXCEPTION: main
05-23 17:39:52.781: E/AndroidRuntime(20945): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.androidtablayoutactivity/com.example.androidtablayoutactivity.MainActivity}: java.lang.ClassNotFoundException: com.example.androidtablayoutactivity.MainActivity
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2038)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2139)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread.access$700(ActivityThread.java:143)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.os.Looper.loop(Looper.java:137)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread.main(ActivityThread.java:4963)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at java.lang.reflect.Method.invokeNative(Native Method)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at java.lang.reflect.Method.invoke(Method.java:511)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at dalvik.system.NativeStart.main(Native Method)
05-23 17:39:52.781: E/AndroidRuntime(20945): Caused by: java.lang.ClassNotFoundException: com.example.androidtablayoutactivity.MainActivity
05-23 17:39:52.781: E/AndroidRuntime(20945):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.Instrumentation.newActivity(Instrumentation.java:1068)
05-23 17:39:52.781: E/AndroidRuntime(20945):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2029)
05-23 17:39:52.781: E/AndroidRuntime(20945):    ... 11 more

Answer 1

请看这个简单的例子，它会帮助你的

活动名称:

  public class TabHostActivity extends Activity {
/** Called when the activity is first created. */
  Button btn1, btn2;
  TabHost tabs;
  TabHost.TabSpec spec;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    tabs = (TabHost) findViewById(R.id.TabHost01);
    tabs.setup();
    Button btn1 = (Button) tabs.getCurrentView()
            .findViewById(R.id.Button01);
    Button btn2 = (Button) tabs.getCurrentView()
            .findViewById(R.id.Button02);
    btn1.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            // TODO Auto-generated method stub
            spec = tabs.newTabSpec("tab1");
            spec.setContent(R.id.tab1);
            spec.setIndicator("Clock");
            tabs.addTab(spec);
        }
    });
    btn2.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            // TODO Auto-generated method stub
            spec = tabs.newTabSpec("tab2");
            spec.setContent(R.id.tab2);
            spec.setIndicator("Button");
            tabs.addTab(spec);
        }
    });
    tabs.setCurrentTab(0);
    }
   }

XML目录:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
 <FrameLayout
    android:id="@+id/tabcontent1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
     <TabHost
        android:id="@+id/TabHost01"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >
         <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <Button
                android:id="@+id/Button01"
                android:layout_width="160dip"
                android:layout_height="65dip"
                android:text="CLOCK" >
            </Button>
            <Button
                android:id="@+id/Button02"
                android:layout_width="160dip"
                android:layout_height="65dip"
                android:text="BUTTON" >
            </Button>
         </TabWidget>
         <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:paddingTop="62px" >
            <AnalogClock
                android:id="@+id/tab1"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent" >
            </AnalogClock>
            <Button
                android:id="@+id/tab2"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:text="A semi_random button" >
            </Button>
         </FrameLayout>
     </TabHost>
  </FrameLayout>
  </LinearLayout>