在我的应用程序中，我在底部有四个选项卡。每个选项卡都有多个活动。为了在单个选项卡中维护多个活动，我使用了 TabGroupActivity 的概念。我的问题是，当我单击特定选项卡时，它的起始活动有在该选项卡的某些子活动处于 onResume() 状态时重新启动。为了清楚地理解，
Tab1-A-->B-->C-->D-->E.
Tab2-M-->N-->B-->C-->D-->E.
Tab3-P.
Tab4-X-->Y-->B-->C-->D-->E.
当我按下 Tab1 时，必须重新启动 A 活动，而 B 或 C 或 D 或 E 活动之一处于 onresume() 状态。同样，Tab2、Tab4 也必须完成。请有人提供我有示例代码，因为我是一个新人。在此先感谢。
我找到了我的问题的解决方案，我只是覆盖了 TabGorupActivity 中的 onResume() 方法。我的 TabGroupActivity 是
package com.rmn.hrt;
import java.util.ArrayList;
import android.app.Activity;
import android.app.ActivityGroup;
import android.app.AlertDialog;
import android.app.LocalActivityManager;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Window;
/**
* The purpose of this Activity is to manage the activities in a tab.
* Note: Child Activities can handle Key Presses before they are seen here.
* @author Eric Harlow
*/
public class TabGroupActivity extends ActivityGroup {
private ArrayList<String> mIdList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (mIdList == null) mIdList = new ArrayList<String>();
}
/**
* This is called when a child activity of this one calls its finish method.
* This implementation calls {@link LocalActivityManager#destroyActivity} on the child activity
* and starts the previous activity.
* If the last child activity just called finish(),this activity (the parent),
* calls finish to finish the entire group.
*/
@Override
public void finishFromChild(Activity child) {
LocalActivityManager manager = getLocalActivityManager();
int index = mIdList.size()-1;
if (index < 1) {
finish();
return;
}
manager.destroyActivity(mIdList.get(index), true);
mIdList.remove(index); index--;
String lastId = mIdList.get(index);
Intent lastIntent = manager.getActivity(lastId).getIntent();
Window newWindow = manager.startActivity(lastId, lastIntent);
setContentView(newWindow.getDecorView());
}
/**
* Starts an Activity as a child Activity to this.
* @param Id Unique identifier of the activity to be started.
* @param intent The Intent describing the activity to be started.
* @throws android.content.ActivityNotFoundException.
*/
public void startChildActivity(String Id, Intent intent) {
Window window = getLocalActivityManager().startActivity(Id,intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
if (window != null) {
mIdList.add(Id);
setContentView(window.getDecorView());
}
}
/**
* The primary purpose is to prevent systems before android.os.Build.VERSION_CODES.ECLAIR
* from calling their default KeyEvent.KEYCODE_BACK during onKeyDown.
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//preventing default implementation previous to android.os.Build.VERSION_CODES.ECLAIR
return true;
}
return super.onKeyDown(keyCode, event);
}
/**
* Overrides the default implementation for KeyEvent.KEYCODE_BACK
* so that all systems call onBackPressed().
*/
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
onBackPressed();
return true;
}
return super.onKeyUp(keyCode, event);
}
/**
* If a Child Activity handles KeyEvent.KEYCODE_BACK.
* Simply override and add this method.
*/
@Override
public void onBackPressed () {
int length = mIdList.size();
if ( length > 1) {
Activity current = getLocalActivityManager().getActivity(mIdList.get(length-1));
current.finish();
}
}
//Removing all string identifiers for the child activities
// except the first activity from mIdList and showing it's view
@Override
protected void onResume() {
LocalActivityManager startManager=getLocalActivityManager();
int index = mIdList.size() - 1;
while(index>=1){
startManager.destroyActivity(mIdList.get(index), true);
mIdList.remove(index);
index--;
}
String lastId = mIdList.get(index);
Intent lastIntent = startManager.getActivity(lastId).getIntent();
Window newWindow =startManager.startActivity(lastId, lastIntent);
setContentView(newWindow.getDecorView());
super.onResume();
}
}
试试这个
TabWidget twidget = mTabHost.getTabWidget();
twidget.getChildAt(0).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//Start you base activity
mTabHost.setCurrentTab(0);
}
});