Android ActivityGroup

Question

我知道ActivityGroup在过去，但我想学习如何使用它。因此，我编写了一个简单的TabHost，并希望使用ActivityGroup显示不同的活动。以下是代码的部分

Player.java

package player.org;

import android.app.Activity;
import android.app.TabActivity;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TabHost;
import android.widget.TabWidget;
import android.widget.TextView;

public class Player extends TabActivity {
    /** Called when the activity is first created. */
    private MediaPlayer media=null;
    private SeekBar progress;
    private View play;
    private Progress p;
     TabHost tabhost;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tabs);
        Resources res=getResources();
        //TabHost tabhost=(TabHost) findViewById(R.id.tabhost);
       // tabhost.setup();
         tabhost=getTabHost();
        TabHost.TabSpec spec;
        Intent intent;
        intent=new Intent(this,Progress.class);
        spec=tabhost.newTabSpec("now playing").setIndicator("Now playing", res.getDrawable(R.drawable.icon))
        .setContent(intent);
        tabhost.addTab(spec);
        intent=new Intent(this,Group.class);
       spec=tabhost.newTabSpec("all_songs").setIndicator("All songs", res.getDrawable(R.drawable.songs))
        .setContent(intent);
        tabhost.addTab(spec);
        //intent=new Intent(this,Progress.class);
        spec=tabhost.newTabSpec("artists").setIndicator("Artists", res.getDrawable(R.drawable.icon))
        .setContent(intent);
        tabhost.addTab(spec);
        spec=tabhost.newTabSpec("alboom").setIndicator("Alboom", res.getDrawable(R.drawable.icon))
                .setContent(intent);
        tabhost.addTab(spec);
        tabhost.setCurrentTab(0);
    }
}

Group.java

import android.os.Bundle;
import android.view.View;

public class Group extends ActivityGroup
    {
        @Override
        public void onCreate(Bundle savedInstanceStated)

        {
            super.onCreate(savedInstanceStated);

             View view = getLocalActivityManager().startActivity("AllSongs",
             new Intent(this, AllSongs.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();


 setContentView(view);
        }

AllSongs.java

package player.org;
import java.util.ArrayList;

import android.R.id;
import android.app.ActivityGroup;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TabHost;

public class AllSongs extends ListActivity{
    ArrayList<String> listItem=new ArrayList<String>();
    ArrayAdapter<String> adapter;
    ListView listView;
    //Player p;
    TabHost tab;
    public void onCreate(Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            //p=new Player();

            adapter=new ArrayAdapter<String>(this,R.layout.list_item,listItem);
            setListAdapter(adapter);
            listView=getListView();
            listView.setTextFilterEnabled(true);
            listView.setOnItemClickListener(listener);

            addItem("vahag");
            addItem("vahagvahag");



        }
    private OnItemClickListener listener=new OnItemClickListener()
    {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub


            Intent intent = new Intent(AllSongs.this,Progress.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            Group group= (Group) getParent();
            View view=group.getLocalActivityManager().startActivity("Progress",intent).getDecorView();

            setContentView(view);

        }


    };
    public void addItem(String s)
        {
            listItem.add(s);
            adapter.notifyDataSetChanged();
        }

}

和Progress.java

package player.org;
import android.app.Activity;
import android.app.ActivityGroup;
import android.app.Dialog;
import android.app.TabActivity;
import android.content.Context;
 public class Progress extends Activity {
    // Called when the activity is first created.     
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
}
}

因此，AllSongs.java试图用进度活动更改当前活动，但是当我按下列表项时，程序已关闭，logChat说

"08-17 12:49:26.471: ERROR/AndroidRuntime(1500)：java.lang.RuntimeException:您的内容必须具有id属性为‘android.R.id.list’的ListView“

我想不出怎么解决这个问题，有人能帮忙吗？

Answer 1

问题似乎是您使用的是ListActivity，但没有按照ListActivity希望它出现的方式定义您的ListView。

来自ListActivity的文档(重点为我)：

ListActivity有一个默认的布局，该布局由屏幕中央的一个全屏列表组成。但是，如果您愿意，可以通过在setContentView()中使用onCreate()设置自己的视图布局来自定义屏幕布局。为此，您自己的视图必须包含一个id "@android:id/list"的ListView对象。