我们可以用以下两种方式之一更改动作栏标题:

In the Manifest: in the manifest file, set the label of each Activity. android:label="@string/TitleWhichYouWantToDisplay" In code: in code, call the setTitle() method with a String or the id of String as the argument. public class MainActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { setTitle(R.string.TitleWhichYouWantToDisplay); // OR You can also use the line below // setTitle("MyTitle") setContentView(R.layout.activity_main); } }

年纪大一点，但也有同样的问题。我是这样做的:

strings.xml

<字符串

确保你在AndroidManifest.xml中设置了这个:

<activity
            ...
            android:label="@string/title_awesome_app" >
            ...
</activity>

这很简单，你不必担心空引用和其他东西。

getActionBar().setTitle("edit your text"); 

ActionBar ab = getActionBar();
TextView tv = new TextView(getApplicationContext());

LayoutParams lp = new RelativeLayout.LayoutParams(
        LayoutParams.MATCH_PARENT, // Width of TextView
        LayoutParams.WRAP_CONTENT);
tv.setLayoutParams(lp);
tv.setTextColor(Color.RED);
ab.setCustomView(tv);

欲了解更多信息，请查看此链接:

http://android--code.blogspot.in/2015/09/android-how-to-change-actionbar-title_21.html

只需在onCreate方法中添加此代码。

setTitle("new title");

在onCreateView中添加这个:

(activity as AppCompatActivity).supportActionBar?.title ="My APP Title"