有标签和的ActivityGroup后退按钮行为 [英] Back button behavior with tabs and ActivityGroup

问题描述

我有一个活动（主），这表明标签是这样的：

I have an Activity (Main) which shows tabs like this:

private void initTabs(){
    mTabHost = getTabHost(); // The activity TabHost

    Intent intent;
    intent = new Intent().setClass(this, MyGroup.class);
    setupTab(intent, "tab");
}

private void setupTab(Intent intent, final String tag) {
    View tabview = createTabView(mTabHost.getContext(), tag);
    TabSpec setContent = mTabHost.newTabSpec(tag).setIndicator(tabview).setContent(intent);
    mTabHost.addTab(setContent);
}

private static View createTabView(final Context context, final String text) {
    View view = LayoutInflater.from(context).inflate(R.layout.tabs_bg, null);

    ((TextView) view.findViewById(R.id.tabsText)).setText(text);
    return view;
}

在 MYGROUP 类是一个的ActivityGroup，它执行以下操作：

The MyGroup class is an ActivityGroup, which does the following:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

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

            state = A;
}

public void openB() {
    Intent i = new Intent(this, ActivityB.class);

    View view = getLocalActivityManager().startActivity("activityB", i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
    this.setContentView(view);
            state = B;
}

所以主有一个 MYGROUP 标签。该 MYGROUP 开始 ActivityA 键，然后进入 ActivityB 。当我美元的 ActivityB 点$ PSS后退按钮，我想回去 ActivityA ，并在回$在 ActivityA 点$ PSS我想关闭该应用程序。

So Main has a tab with a MyGroup. The MyGroup starts with ActivityA and then goes to ActivityB. When I press the back button in ActivityB, I want to go back to ActivityA, and on back press in ActivityA I want to close the app.

这是我是如何做到这一点。在 ActivityB ：

This is how I've done that. In ActivityB:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    System.out.println("ActivityB PRESSED");
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        MyGroup mg = (MyGroup) getParent();
        return mg.onKeyDown(keyCode, event);
    }
    return super.onKeyDown(keyCode, event);
}

在 ActivityA 相同的：

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        System.out.println("ActivityA PRESSED");
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            MyGroup mg = (MyGroup) getParent();
            return mg.onKeyDown(keyCode, event);
        }
        return super.onKeyDown(keyCode, event);
    }

现在，在 MYGROUP ：

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            System.out.println("MG PRESSED");   
                if (state == A)
                return false;
            else if (state == B) {
            setContentView(getLocalActivityManager().startActivity("activityA", new Intent(this, ActivityA.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView());
                state = A;
                return true;
        }

        return false;
        }
        return super.onKeyDown(keyCode, event);
    }

最后，在主，只是一个System.out的：

Finally, in Main, just a system.out:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    System.out.println("MAIN PRESSED");
    return super.onKeyDown(keyCode, event);
}

现在，这是我目前的行为，我不想要的：

Now this is my current behavior, which I don't want:

• 当应用程序启动后，我在ActivityA。后退按钮 - >应用程序关闭。确定。
• 当应用程序启动后，ActivityA - > ActivityB - >后退按钮 - > ActivityA。确定。
• 当应用程序启动后，ActivityA - > ActivityB - >返回 - > ActivityA - > ActivityB - >返回 - >应用程序关闭。也不行！

• When app started, I'm in ActivityA. Backbutton -> app closes. OK.
• When app started, ActivityA -> ActivityB -> Back button -> ActivityA. OK.
• When app started, ActivityA -> ActivityB -> Back -> ActivityA -> ActivityB -> Back -> app closes. NOT OK!

显然，第二次ActivityB显示，后退按钮是由主，而不是 ActivityB 处理或 MYGROUP 。

Apparently, the second time ActivityB is shown, the back button is being handled by Main, instead of ActivityB or MyGroup.

我该如何解决这个问题？

How can I fix this?

修改

我添加了一个ActivityC。这似乎是在头两个活动的行为是正常的，从第三上的主活动处理的按钮preSS。

I've added an ActivityC. It seems like behaviour in the first two activities is normal, and from the third on, the Main activity handles the button press.

所以，A - > B - > A是被处理 - > B - >主

So A -> B -> A is handled by A -> B -> Main

和A - > B - > C由一个处理 - > B - >主

and A -> B -> C is handled by A -> B -> Main.

推荐答案

于是，我找到了答案。

我在主要，这似乎是这个问题的原因是AdMob的AD浏览报。这是XML：

I have an admob adview in my Main, which seems the cause of this problem. This is the xml:

    <?xml version="1.0" encoding="utf-8"?>
    <TabHost
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
        android:id="@android:id/tabhost"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"    
                    android:padding="0dp">
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true" />
        <com.google.ads.AdView
            android:id="@+id/adView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            ads:adUnitId="@string/adkey"
            ads:adSize="BANNER"
            ads:loadAdOnCreate="false"
            android:layout_alignParentBottom="true" 
            android:focusable="false"/>
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_above="@id/adView"
            android:layout_below="@android:id/tabs" />

    </RelativeLayout>
</TabHost>

当我删除AD浏览报，不会出现问题。

When I remove the adview, the problem doesn't occur.

现在要解决这个问题，我已经将XML变成这样：

Now to solve this, I've changed the xml into this:

<?xml version="1.0" encoding="utf-8"?>
<TabHost
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <FrameLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:padding="0dp">
            <TabWidget
                android:id="@android:id/tabs"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_alignParentTop="true" />

            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:layout_below="@android:id/tabs" />
        </RelativeLayout>
        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content">
            <com.google.ads.AdView
                android:id="@+id/adView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                ads:adUnitId="@string/adkey"
                ads:adSize="BANNER"
                ads:loadAdOnCreate="false"
                android:layout_alignParentBottom="true"
                android:focusable="false" />
        </RelativeLayout>
    </FrameLayout>
</TabHost>

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