是的，可以将字体设置为整个应用程序。

实现这一点的最简单方法是将所需的字体打包到应用程序中。

要做到这一点，只需在项目根目录中创建一个assets/文件夹，并将您的字体(放在 TrueType，或TTF表单)。

例如，您可以创建资产/字体/并将您的TTF文件放在那里。

public class FontSampler extends Activity {
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
TextView tv=(TextView)findViewById(R.id.custom);

Typeface face=Typeface.createFromAsset(getAssets(), "fonts/HandmadeTypewriter.ttf");
tv.setTypeface(face);
}
}

Tom的解决方案很好，但只适用于TextView和EditText。

如果你想覆盖大部分的视图(RadioGroup, TextView，复选框…)，我创建了一个方法:

protected void changeChildrenFont(ViewGroup v, Typeface font){
    for(int i = 0; i < v.getChildCount(); i++){

        // For the ViewGroup, we'll have to use recursivity
        if(v.getChildAt(i) instanceof ViewGroup){
            changeChildrenFont((ViewGroup) v.getChildAt(i), font);
        }
        else{
            try {
                Object[] nullArgs = null;
                //Test wether setTypeface and getTypeface methods exists
                Method methodTypeFace = v.getChildAt(i).getClass().getMethod("setTypeface", new Class[] {Typeface.class, Integer.TYPE});
                //With getTypefaca we'll get back the style (Bold, Italic...) set in XML
                Method methodGetTypeFace = v.getChildAt(i).getClass().getMethod("getTypeface", new Class[] {});
                Typeface typeFace = ((Typeface)methodGetTypeFace.invoke(v.getChildAt(i), nullArgs));
                //Invoke the method and apply the new font with the defined style to the view if the method exists (textview,...)
                methodTypeFace.invoke(v.getChildAt(i), new Object[] {font, typeFace == null ? 0 : typeFace.getStyle()});
            }
            //Will catch the view with no such methods (listview...)
            catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

该方法将返回视图集的XML样式(粗体，斜体…)，并在它们存在时应用它们。

对于ListView，我总是创建一个适配器，并在getView中设置字体。

在API 26中使用build。Gradle 3.0.0及更高版本可以在res中创建字体目录 把这句话用在你的风格里

<item name="android:fontFamily">@font/your_font</item>

对于变更构建。Gradle在你的构建中使用这个。gradle dependecies

classpath 'com.android.tools.build:gradle:3.0.0'

我写了一个类，将字体分配给当前视图层次结构中的视图，并基于当前字体属性(粗体，正常，如果你想，你可以添加其他样式):

public final class TypefaceAssigner {

public final Typeface DEFAULT;
public final Typeface DEFAULT_BOLD;

@Inject
public TypefaceAssigner(AssetManager assetManager) {
    DEFAULT = Typeface.createFromAsset(assetManager, "TradeGothicLTCom.ttf");
    DEFAULT_BOLD = Typeface.createFromAsset(assetManager, "TradeGothicLTCom-Bd2.ttf");
}

public void assignTypeface(View v) {
    if (v instanceof ViewGroup) {
        for (int i = 0; i < ((ViewGroup) v).getChildCount(); i++) {
            View view = ((ViewGroup) v).getChildAt(i);
            if (view instanceof ViewGroup) {
                setTypeface(view);
            } else {
                setTypeface(view);
            }
        }
    } else {
        setTypeface(v);
    }
}

private void setTypeface(View view) {
    if (view instanceof TextView) {
        TextView textView = (TextView) view;
        Typeface typeface = textView.getTypeface();
        if (typeface != null && typeface.isBold()) {
            textView.setTypeface(DEFAULT_BOLD);
        } else {
            textView.setTypeface(DEFAULT);
        }
    }
}
}

现在，在onViewCreated或onCreateView的所有片段中，在onCreate中的所有活动中，在getView或newView中的所有视图适配器中，只需调用:

typefaceAssigner.assignTypeface(view);

为萨玛林工作。Android:

类:

public class FontsOverride
{
    public static void SetDefaultFont(Context context, string staticTypefaceFieldName, string fontAssetName)
    {
        Typeface regular = Typeface.CreateFromAsset(context.Assets, fontAssetName);
        ReplaceFont(staticTypefaceFieldName, regular);
    }

    protected static void ReplaceFont(string staticTypefaceFieldName, Typeface newTypeface)
    {
        try
        {
            Field staticField = ((Java.Lang.Object)(newTypeface)).Class.GetDeclaredField(staticTypefaceFieldName);
            staticField.Accessible = true;
            staticField.Set(null, newTypeface);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

应用程序实现:

namespace SomeAndroidApplication
{
    [Application]
    public class App : Application
    {
        public App()
        {

        }

        public App(IntPtr handle, JniHandleOwnership transfer)
            : base(handle, transfer)
        {

        }

        public override void OnCreate()
        {
            base.OnCreate();

            FontsOverride.SetDefaultFont(this, "MONOSPACE", "fonts/Roboto-Light.ttf");
        }
    }
}

风格:

<style name="Theme.Storehouse" parent="Theme.Sherlock">
    <item name="android:typeface">monospace</item>
</style>

package com.theeasylearn.demo.designdemo;
import android.content.Context;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.widget.TextView;

public class MyButton extends TextView {

    public MyButton(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    public MyButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MyButton(Context context) {
        super(context);
        init();
    }

    private void init() {

            Typeface tf =
                    Typeface.createFromAsset(
                            getContext().getAssets(), "angelina.TTF");
            setTypeface(tf);

    }

}