Android系统。 如何更改选项卡中的活动

Question

Following situation: I have TabActivity with eg three tabs, TabA, TabB, TabC.

There are a button in activity (Act_C_1) of TabC. So if the user clicks on that button, another activity (Act_C_2) should occur in TabC.

I thank you in advance for any suggestions / or ideas.

Mur

UPD:

Here is my code

TabActivity with three Activities:

public class TabScreen extends TabActivity
{
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.tab_menu);

        TabHost tabHost = getTabHost();  // The activity TabHost
        TabHost.TabSpec spec;  // Resusable TabSpec for each tab
        Intent intent;  // Reusable Intent for each tab

        intent = new Intent().setClass(this, SecondActivity.class);

        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabHost.newTabSpec("tab_1").setIndicator("Tab1",null).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, ThirdActivity.class);
        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabHost.newTabSpec("tab_2").setIndicator("Tab2",null).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, FourthActivity.class);
        spec = tabHost.newTabSpec("tab_3").setIndicator("Tab3",null).setContent(intent);
        tabHost.addTab(spec);
    }

}

Activity 'Act_C_1' or FourthActivity.java:

public class FourthActivity extends Activity implements OnClickListener
{
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fourth);

        Button BtnWeiter = (Button)findViewById(R.id.BtnWeiter);
        BtnWeiter.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) 
    {                    
        // I also tried to use LocalActivityManager
        // TabActivity parentTabActivity = (TabActivity) getParent();            
        // LocalActivityManager manager = parentTabActivity.getLocalActivityManager();
        // manager.destroyActivity("tab_3", true);
        // manager.startActivity("tab_3", new Intent(this, FourthActivity.class));
        finish();
        startActivity(new Intent(this, FourthActivity.class));            
    }        
}

Answer 1

The Activities in the tab can be switched in the following manner.

First Let us understand the flow:

1. We have in a Tab host , activity (say a list) from which we need to go to the next Activity (say details for the clicked item) under the same tab. For this we can use the concept of replacing the activity.Also setting the flags for the tab selected and other for knowing that details are being shown now

2. When we press back we should get the previous activity under the same tab.For this instead of again replacing the activity we can refresh the tab while using the particular flag for tab which was selected. Also if flag for show details is true we'll go the the list in the same tab or else we will go the activity before the tabwidget (normal use of onBackPressed)

The code can be as follows..

1. For going from list to details...

(This can be in the onClickListener)

private OnClickListener textListener = new OnClickListener() {

    @Override
    public void onClick(View v) {
        Constants.SHOW_DETAILS = true;
        Intent intent = new Intent(context, DetailsActivity.class);
        replaceContentView("activity3", intent);
        }
};

public void replaceContentView(String id, Intent newIntent) {
    View view = ((ActivityGroup) context)
            .getLocalActivityManager()
            .startActivity(id,
                    newIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))
            .getDecorView();
    ((Activity) context).setContentView(view);

}

1. When back pressed is done we override on BackPressed in each of the Activity under the tab to go to the list again from the details screen

    @Override public void onBackPressed() { // TODO Auto-generated method stub super.onBackPressed(); if (MathHelper.SHOW_DETAILS) { Log.e("back", "pressed accepted"); Constants.LIST_ACTIVITY = 1; Constants.SHOW_DETAILS = false; Intent intent = new Intent(this, Tab_widget.class); startActivity(intent); finish(); } } 

The most important part here is Constants.LIST_ACTIVITY = 1; it indicates which tab we are in. so the corresponding activities will have its value as 0,1,2...etc

Again to load the correct list (Activty) when the tab activity is refreshed we have to include this in the TabWidget onCreate after the creation of the tabs

tabHost.setCurrentTab(Constants.LIST_ACTIVITY);

Answer 2

Just use Intent.FLAG_ACTIVITY_CLEAR_TOP flag to replace an activity for necessary tab.

intent = new Intent().setClass(this, YourActivity.class);
spec   = tabHost.newTabSpec("tab1").setIndicator("Tab1",null)
        .setContent(intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
tabHost.addTab(spec);

Answer 3

Just add this for all tabs:

yourTabHost.getChildAt(0).setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        getTabHost().setCurrentTab(0);
    }
});

Answer 4

Handle the onClick event for button

finish() the activity Add startActivity method to start another activity.

Thanks