如何对操作栏上的后退按钮进行编程以返回到上一个 activity？

Question

我想知道如何对操作栏中的后退按钮进行编程以恢复到之前的 activity 并完成刚刚显示的 activity？

About.class

public class About extends FragmentActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.about);
        getActionBar().setDisplayHomeAsUpEnabled(true);
// Get tracker.
        Tracker t = ((AnalyticsTracker) getApplication()).getTracker(AnalyticsTracker.TrackerName.APP_TRACKER);

// Enable Display Features so you can see demographics in Google Analytics
        t.enableAdvertisingIdCollection(true);

// Set screen name.
        t.setScreenName("About");

// Send a screen view.
        t.send(new HitBuilders.AppViewBuilder().build());
        FragmentManager fragmentManager = getFragmentManager();
        android.app.FragmentTransaction fragmentTransaction =
                fragmentManager.beginTransaction();

        adView ls_fragment = new adView();
        fragmentTransaction.replace(android.R.id.content, ls_fragment);

        AdView mAdView = (AdView) findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().build();
        mAdView.loadAd(adRequest);

    }

}

关于页面的布局。 about.xml

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:ads="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id = "@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/black"
        >


    <RelativeLayout
            android:background="@mipmap/home"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <ImageView
                android:layout_width="200dp"
                android:layout_height="200dp"
                android:id="@+id/imageView"
                android:background="@mipmap/ic_launcher"
                android:layout_alignParentTop="true"
                android:layout_centerHorizontal="true" />

        <TextView
            android:layout_width="300dp"
            android:layout_height="250dp"
            android:id="@+id/textView9"
            android:gravity="center"
            android:textSize="16dp"
            android:text="@string/aboutText"
            android:background="@drawable/text"
            android:layout_below="@+id/imageView"
            android:layout_centerHorizontal="true" />

        <fragment
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:name="course.labs.converjz.adView"
            android:id="@+id/fragment"
            tools:layout="@layout/adview"
            android:layout_gravity="center|bottom"
            android:layout_alignWithParentIfMissing="false"
            android:layout_alignParentBottom="true"
            android:layout_alignParentStart="true" />

    </RelativeLayout>
</RelativeLayout>

创建操作栏并向其添加后退按钮的特定样式。 Styles.xml

 <style name= "MenuBar" parent="@style/AppBaseTheme">
        <item name = "android:homeAsUpIndicator">@mipmap/back</item>

</style>

后退按钮图像位于 mipmap 图标文件夹中。

Answer 1

试试这个

@Override
        public boolean onOptionsItemSelected(MenuItem item) {
                switch (item.getItemId()) {
                case android.R.id.home:
                       finish();
                   break;
                }
                return true;
        }

Answer 2

只需将 getActionBar 更改为 getSupportActionBar 如图：

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

如何对操作栏上的后退按钮进行编程以返回到上一个 activity？

How can I program the back button on the action bar to go back to the previous activity?

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back-button

android-actionbar