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我正在尝试根据 Android 设计指南 ( http://developer.android.com/design/patterns/navigation.html ) 实现 ActionBar UP 导航。

对于大多数用例来说，这很简单，但假设我有一个名为 Activity2A 的 Activity，我可以通过 2 条不同的路径到达：

MainActivity -> Activity1A -> Activity2A

MainActivity -> Activity1B -> Activity2A

Activity2A 的逻辑父级是 Activity1A，因此应该在从 Activity2A 向上导航时启动。我根据官方教程在清单中设置了这个：

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="17" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/Theme.Sherlock.Light" >

    <!-- Main menu -->
    <activity
        android:name="hu.scythe.upnavigation.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <!-- Level 1 -->
    <activity
        android:name="hu.scythe.upnavigation.Activity1A"
        android:label="@string/title_activity_activity1"
        android:parentActivityName="hu.scythe.upnavigation.MainActivity" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="hu.scythe.upnavigation.MainActivity" />
    </activity>
    <activity
        android:name="hu.scythe.upnavigation.Activity1B"
        android:label="@string/title_activity_activity1_b"
        android:parentActivityName="hu.scythe.upnavigation.MainActivity" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="hu.scythe.upnavigation.MainActivity" />
    </activity>

    <!-- Level 2 -->
    <activity
        android:name="hu.scythe.upnavigation.Activity2A"
        android:label="@string/title_activity_activity2"
        android:parentActivityName="hu.scythe.upnavigation.Activity1A" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="hu.scythe.upnavigation.Activity1A" />
    </activity>
</application>

我在 Activity2A 中使用以下代码进行向上导航：

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        // Respond to the action bar's Up/Home button
        case android.R.id.home:
            Intent upIntent = NavUtils.getParentActivityIntent(this);
            if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
                // This activity is NOT part of this app's task, so create a new
                // task
                // when navigating up, with a synthesized back stack.
                TaskStackBuilder.create(this)
                // Add all of this activity's parents to the back stack
                        .addNextIntentWithParentStack(upIntent)
                        // Navigate up to the closest parent
                        .startActivities();
            } else {
                // This activity is part of this app's task, so simply
                // navigate up to the logical parent activity.
                NavUtils.navigateUpTo(this, upIntent);
            }
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

如果我在第一条路径上导航到 Activity2A，它工作正常（所以它的逻辑父级已经在 Activity 堆栈上）。但是使用第二条路径，单击 UP 按钮会将我带到 MainActivity（根），而不是 Activity1A（逻辑父）。我正在 Android 4.2 上测试此代码。

我究竟做错了什么？

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0 回答 0