为了补充@Sam_D的答案，我必须这样做才能使它工作:

this.setTitle("my title!");
((TextView)v.findViewById(R.id.title)).setText(this.getTitle());
TextView title = ((TextView)v.findViewById(R.id.title));
title.setEllipsize(TextUtils.TruncateAt.MARQUEE);
title.setMarqueeRepeatLimit(1);
// in order to start strolling, it has to be focusable and focused
title.setFocusable(true);
title.setSingleLine(true);
title.setFocusableInTouchMode(true);
title.requestFocus();

这似乎有点过分-两次引用v.f entviewbyid (R.id.title)) -但这是唯一的方法，它会让我这样做。

以下代码将适用于所有版本。我确实在gingerbread设备和JellyBean设备上检查了这一点

 private void actionBarIdForAll()
    {
        int titleId = 0;

        if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.HONEYCOMB)
        {
            titleId = getResources().getIdentifier("action_bar_title", "id", "android");
        }
        else
        {
          // This is the id is from your app's generated R class when ActionBarActivity is used for SupportActionBar

            titleId = R.id.action_bar_title;
        }

        if(titleId>0)
        {
            // Do whatever you want ? It will work for all the versions.

            // 1. Customize your fonts
            // 2. Infact, customize your whole title TextView

            TextView titleView = (TextView)findViewById(titleId);
            titleView.setText("RedoApp");
            titleView.setTextColor(Color.CYAN);
        }
    }

这是一个丑陋的黑客，但你可以这样做(因为action_bar_title是隐藏的):

    try {
        Integer titleId = (Integer) Class.forName("com.android.internal.R$id")
                .getField("action_bar_title").get(null);
        TextView title = (TextView) getWindow().findViewById(titleId);
        // check for null and manipulate the title as see fit
    } catch (Exception e) {
        Log.e(TAG, "Failed to obtain action bar title reference");
    }

这段代码适用于后姜饼设备，但也可以很容易地扩展到动作栏Sherlock

附注:基于@pjv评论，有一个更好的方法找到操作栏标题id

final int titleId = 
    Resources.getSystem().getIdentifier("action_bar_title", "id", "android");

    ActionBar actionBar = getSupportActionBar();
    TextView tv = new TextView(getApplicationContext());
    Typeface typeface = ResourcesCompat.getFont(this, R.font.monotype_corsiva);
    RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.MATCH_PARENT, // Width of TextView
            RelativeLayout.LayoutParams.WRAP_CONTENT); // Height of TextView
    tv.setLayoutParams(lp);
    tv.setText("Your Text"); // ActionBar title text
    tv.setTextSize(25);
    tv.setTextColor(Color.WHITE);
    tv.setTypeface(typeface, typeface.ITALIC);
    actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
    actionBar.setCustomView(tv);

从Android支持库v26 + Android Studio 3.0起，这个过程变得简单如轻弹!!

按照以下步骤更改工具栏标题的字体:

Read Downloadable Fonts & select any font from the list (my recommendation) or load a custom font to res > font as per Fonts in XML In res > values > styles, paste the following (use your imagination here!) <style name="TitleBarTextAppearance" parent="android:TextAppearance"> <item name="android:fontFamily">@font/your_desired_font</item> <item name="android:textSize">23sp</item> <item name="android:textStyle">bold</item> <item name="android:textColor">@android:color/white</item> </style> Insert a new line in your Toolbar properties app:titleTextAppearance="@style/TextAppearance.TabsFont" as shown below <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:background="?attr/colorPrimary" app:titleTextAppearance="@style/TitleBarTextAppearance" app:popupTheme="@style/AppTheme.PopupOverlay"/> Enjoy Custom Actionbar Title font styling!!

我同意这不是完全支持的，但以下是我所做的。您可以为操作栏使用自定义视图(它将显示在图标和操作项之间)。我正在使用一个自定义视图，我已经禁用了本机标题。我所有的活动都继承自一个活动，它在onCreate中有这样的代码:

this.getActionBar().setDisplayShowCustomEnabled(true);
this.getActionBar().setDisplayShowTitleEnabled(false);

LayoutInflater inflator = LayoutInflater.from(this);
View v = inflator.inflate(R.layout.titleview, null);

//if you need to customize anything else about the text, do it here.
//I'm using a custom TextView with a custom font in my layout xml so all I need to do is set title
((TextView)v.findViewById(R.id.title)).setText(this.getTitle());

//assign the view to the actionbar
this.getActionBar().setCustomView(v);

我的layout xml (R.layout。标题视图在上面的代码)看起来像这样:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent" >

<com.your.package.CustomTextView
        android:id="@+id/title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginLeft="10dp"
            android:textSize="20dp"
            android:maxLines="1"
            android:ellipsize="end"
            android:text="" />
</RelativeLayout>