Question

我如何解释我的问题？

我有一个使用标签的应用程序（通过Intents，而不是视图）。我已经在每个视图中实现了导航而没有遇到任何麻烦，但是我需要从全屏和横向模式中的一个Activity中的ListView中启动视频播放器（所以没有标签）。但是当我想要播放播放器时（通过按回或调用finish（）;），我的应用程序将关闭（LogCat中没有例外）并返回主屏幕。所以我需要的是当我退出全屏活动（为播放器启动）时，回到我的应用程序，与选项卡一起。

这是我的代码：

//Main activity : 

package com.ccn;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class CCNMain extends TabActivity {
    public static TabHost tabHost;
    static CCNMain  myActivity = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myActivity = this;

        Resources res = getResources();
        tabHost = getTabHost();
        TabHost.TabSpec spec; // reusable tabspec for each tab
        Intent intent;

        intent = new Intent().setClass(this, NewsGroup.class);
        spec = tabHost.newTabSpec("nnews")
        .setIndicator("A la une",res.getDrawable(R.drawable.home))
        .setContent(intent);
        tabHost.addTab(spec);

        /*intent = new Intent().setClass(this, ArticlesGroup.class);
        spec = tabHost.newTabSpec("aarticles")
        .setIndicator("Articles",res.getDrawable(R.drawable.articles))
        .setContent(intent);
        tabHost.addTab(spec);*/

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("vvideos")
        .setIndicator("Vidéos",res.getDrawable(R.drawable.video))
        .setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("ccontact")
        .setIndicator("Contact",res.getDrawable(R.drawable.contact))
        .setContent(intent);
        tabHost.addTab(spec);

        tabHost.setCurrentTab(0);
    }
}

//ContactGroup : 
package com.ccn;

import java.util.ArrayList;


import android.app.ActivityGroup;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class ContactGroup extends ActivityGroup {
    // Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view  
    public static ContactGroup groupContact;  

        // Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.  
    private ArrayList<View> history;  
  @Override
    protected void onCreate(Bundle savedInstanceState) {  
          super.onCreate(savedInstanceState);  
          this.history = new ArrayList<View>();  
          groupContact = this;  

              // Start the root activity within the group and get its view  
          View view = getLocalActivityManager().startActivity("idHoraireActivity", new  
                                            Intent(this,ContactActivity.class)  
                                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))  
                                            .getDecorView();  

              // Replace the view of this ActivityGroup  
          replaceView(view);  

       }  

    public void replaceView(View v) {  
                // Adds the old one to history  
        history.add(v);  
                // Changes this Groups View to the new View.  
        setContentView(v);  
    }  

    public void back() {  
        if(history.size() > 1) {  
            history.remove(history.size()-1);  
            setContentView(history.get(history.size()-1));  
        }else {  
            finish();  
        }  
    }  
    //@Override  
    public void onBackPressed() {  
        ContactGroup.groupContact.back();  
        return;  
    }

}

//ContactActivity:
package com.ccn;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;

public class ContactActivity extends Activity {
    static ContactActivity bidule = null;
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);
        bidule = this;
        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent i = new Intent();
                i.setClass(getApplicationContext(), videoPlayerActivity.class);
                //i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                bidule.startActivity(i);
                ContactActivity.this.startActivityForResult(i, 0);
            }
        });

    }

}

//VideoPlayerActivity:
package com.ccn;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.VideoView;


public class videoPlayerActivity extends Activity {

    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);


        //the VideoView will hold the video
        String url = // Video url;

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                finish();
            }
        });
    }


}

在这里我的清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.ccn"
      android:versionCode="1"
      android:versionName="1.0">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>


    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".CCNMain"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="ArticlesGroup"></activity>
        <activity android:name="ContactGroup"></activity>
        <activity android:name="NewsGroup"></activity>
        <activity android:name="NewsActivity"></activity>
        <activity android:name="ArticlesAvtivity"></activity>
        <activity android:name="ContactActivity"></activity>
        <activity android:name="videoPlayerActivity" android:theme="@android:style/Theme.NoTitleBar.Fullscreen" android:screenOrientation="landscape"></activity>

    </application>
</manifest>

感谢您的帮助。我的猜测：它与我调用startActivity和Intent标志的地方有关。你觉得怎么样？

Answer 1

<强>被修改

/Main activity : 

package com.ccn;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class CCNMain extends TabActivity {
    public static TabHost tabHost;
    static CCNMain  myActivity = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myActivity = this;

        Resources res = getResources();
        tabHost = getTabHost();
        TabHost.TabSpec spec; // reusable tabspec for each tab
        Intent intent;

        intent = new Intent().setClass(this, NewsGroup.class);
        spec = tabHost.newTabSpec("nnews")
        .setIndicator("A la une",res.getDrawable(R.drawable.home))
        .setContent(intent);
        tabHost.addTab(spec);

        /*intent = new Intent().setClass(this, ArticlesGroup.class);
        spec = tabHost.newTabSpec("aarticles")
        .setIndicator("Articles",res.getDrawable(R.drawable.articles))
        .setContent(intent);
        tabHost.addTab(spec);*/

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("vvideos")
        .setIndicator("Vidéos",res.getDrawable(R.drawable.video))
        .setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("ccontact")
        .setIndicator("Contact",res.getDrawable(R.drawable.contact))
        .setContent(intent);
        tabHost.addTab(spec);

        tabHost.setCurrentTab(0);
    }
}

//ContactGroup : 
package com.ccn;

import java.util.ArrayList;


import android.app.ActivityGroup;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class ContactGroup extends ActivityGroup {
    // Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view  
    public static ContactGroup groupContact;  

        // Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.  
    private ArrayList<View> history;  
  @Override
    protected void onCreate(Bundle savedInstanceState) {  
          super.onCreate(savedInstanceState);  
          this.history = new ArrayList<View>();  
          groupContact = this;  

              // Start the root activity within the group and get its view  
          View view = getLocalActivityManager().startActivity("idHoraireActivity", new  
                                            Intent(this,ContactActivity.class)  
                                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))  
                                            .getDecorView();  

              // Replace the view of this ActivityGroup  
          replaceView(view);  

       }  

    public void replaceView(View v) {  
                // Adds the old one to history  
        history.add(v);  
                // Changes this Groups View to the new View.  
        setContentView(v);  
    }  

    public void back() {  
        if(history.size() > 1) {  
            history.remove(history.size()-1);  
            setContentView(history.get(history.size()-1));  
        }else {  
            finish();  
        }  
    }  
    //@Override  
    public void onBackPressed() {  
        ContactGroup.groupContact.back();  
        return;  
    }

}

//ContactActivity:
package com.ccn;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;

public class ContactActivity extends Activity {
    //static ContactActivity bidule = null;
      ContactGroup contactGroup = null;
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);
        //bidule = this;
        contactGroup = new ContactGroup();

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                View view = getLocalActivityManager().startActivity("videoPlayerActivity", new  
                                            Intent(this,videoPlayerActivity.class)  
                                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))  
                                            .getDecorView();
                contactGroup.replaceView(view);
            }
        });

    }

}

//VideoPlayerActivity:
package com.ccn;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.VideoView;


public class videoPlayerActivity extends Activity {
     ContactGroup contactGroup = null;

    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);
         ContactGroup contactGroup = new  ContactGroup();

        //the VideoView will hold the video
        String url = // Video url;

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                 contactGroup.back();
            }
        });
    }

摘要：

您必须调用您的活动组的repalaceView和back方法。当您想要开始新活动时使用replaceView()，当您想要完成活动时，请使用back()

Answer 2

我已经实施了同样的案例。但是没有使用ActivityGroup。在测试中，很明显它的反应并不防水。当我启动Mediaplayer活动并在堆栈中放入新活动时，操作系统正确处理后台事件。

public class VideoActivity extends Activity {
private ListView mListView;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...
    mListView = (ListView)findViewById(R.id.list);
    mListView.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent().setClass(view.getContext(), ViewVideoActivity.class);
            startActivity(intent);
        }
    });
}

VieoVideoActivity是横向强制的全屏活动，没有重写的关键事件实现。

Answer 3

我希望我能正确理解你的查询（请纠正我）。 TabActivity中有多个选项卡，除了一个与另一个Activity相关联的选项卡外，其中一个选项卡应位于TabActivity的“内部”。对于视频，您希望它在TabActivity的相同级别（不在内部）启动。这样系统就可以处理VideoActivity的后台事件。

|     |
|     |
|T (1)| <- tab activity with tab#1
-------

选择标签＃2：

|     |
|     |
|T (2)| <- tab activity with tab#2
-------

选择标签＃video：

|     |
|Video| <- video activity
|T (2)| <- tab activity with tab#2
-------

由于您可以毫无问题地创建“子活动”，这里我只是向您展示如何创建外部活动意图：

private void createExternalTab(Class clazz, String tag, String label, int iconResId) {
    // intent to launch the activity externally
    final Intent intent = new Intent(this, clazz);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    tabHost.addTab(tabHost.newTabSpec(tag)
            .setContent(R.id.dummy)
            .setIndicator(label, iconResId));
    // find the recently added tab
    TabWidget w = tabHost.getTabWidget();
    View view = w.getChildAt(w.getChildCount() - 1);
    // here is the magic!
    view.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(intent);
        }
    });
}

以下是TabActivity布局：

<?xml version="1.0" encoding="utf-8"?>

<TabHost
    android:id="@android:id/tabhost"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <View
                android:id="@+id/dummy"
                android:layout_width="0dp"
                android:layout_height="0dp"/>

            </FrameLayout>

        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:orientation="horizontal"
            android:showDividers="none"/>
    </RelativeLayout>

</TabHost>

注1：我的代码适用于FragmentActivity

注意2：这里的关键点是：将标签内容映射到R.id.tabcontent中的不可见元素。然后修改选项卡的onClickListener，以便在TabActivity下调用Intent，而不是由TabWidget / TabHost启动。

回到之前的TabActivity

3 个答案: