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);

    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);

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>

我只是在onCreate()函数中做了以下工作:

TypefaceSpan typefaceSpan = new TypefaceSpan("font_to_be_used");
SpannableString str = new SpannableString("toolbar_text");
str.setSpan(typefaceSpan,0, str.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
getSupportActionBar().setTitle(str);

我正在使用支持库，如果你不使用它们，我猜你应该切换到getActionBar()而不是getSupportActionBar()。

在Android Studio 3中，您可以按照以下说明添加自定义字体https://developer.android.com/guide/topics/ui/look-and-feel/fonts-in-xml.html，然后在“font_to_be_used”中使用您新添加的字体

如果你想在整个活动中设置所有textview的字体，你可以使用这样的东西:

public static void setTypefaceToAll(Activity activity)
{
    View view = activity.findViewById(android.R.id.content).getRootView();
    setTypefaceToAll(view);
}

public static void setTypefaceToAll(View view)
{
    if (view instanceof ViewGroup)
    {
        ViewGroup g = (ViewGroup) view;
        int count = g.getChildCount();
        for (int i = 0; i < count; i++)
            setTypefaceToAll(g.getChildAt(i));
    }
    else if (view instanceof TextView)
    {
        TextView tv = (TextView) view;
        setTypeface(tv);
    }
}

public static void setTypeface(TextView tv)
{
    TypefaceCache.setFont(tv, TypefaceCache.FONT_KOODAK);
}

TypefaceCache:

import java.util.TreeMap;

import android.graphics.Typeface;
import android.widget.TextView;

public class TypefaceCache {

    //Font names from asset:
    public static final String FONT_ROBOTO_REGULAR = "fonts/Roboto-Regular.ttf";
    public static final String FONT_KOODAK = "fonts/Koodak.ttf";

    private static TreeMap<String, Typeface> fontCache = new TreeMap<String, Typeface>();

    public static Typeface getFont(String fontName) {
        Typeface tf = fontCache.get(fontName);
        if(tf == null) {
            try {
                tf = Typeface.createFromAsset(MyApplication.getAppContext().getAssets(), fontName);
            }
            catch (Exception e) {
                return null;
            }
            fontCache.put(fontName, tf);
        }
        return tf;
    }

    public static void setFont(TextView tv, String fontName)
    {
        tv.setTypeface(getFont(fontName));
    }
}

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!!