综上所述：
选项1： 使用反射来应用字体（结合weston和Roger Huang的答案）：
import java.lang.reflect.Field;
import android.content.Context;
import android.graphics.Typeface;
public final class FontsOverride {
public static void setDefaultFont(Context context,
String staticTypefaceFieldName, String fontAssetName) {
final Typeface regular = Typeface.createFromAsset(context.getAssets(),
fontAssetName);
replaceFont(staticTypefaceFieldName, regular);
}
protected static void replaceFont(String staticTypefaceFieldName,final Typeface newTypeface) {
if (isVersionGreaterOrEqualToLollipop()) {
Map<String, Typeface> newMap = new HashMap<String, Typeface>();
newMap.put("sans-serif", newTypeface);
try {
final Field staticField = Typeface.class.getDeclaredField("sSystemFontMap");
staticField.setAccessible(true);
staticField.set(null, newMap);
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
} else {
try {
final Field staticField = Typeface.class.getDeclaredField(staticTypefaceFieldName);
staticField.setAccessible(true);
staticField.set(null, newTypeface);
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
}
在应用程序类中的用法：
public final class Application extends android.app.Application {
@Override
public void onCreate() {
super.onCreate();
FontsOverride.setDefaultFont(this, "DEFAULT", "MyFontAsset.ttf");
FontsOverride.setDefaultFont(this, "MONOSPACE", "MyFontAsset2.ttf");
FontsOverride.setDefaultFont(this, "SERIF", "MyFontAsset3.ttf");
FontsOverride.setDefaultFont(this, "SANS_SERIF", "MyFontAsset4.ttf");
}
}
设置一种样式来强制整个字体应用程序（基于lovefish）：
棒棒糖前：
<resources>
<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
</style>
<!-- Application theme. -->
<style name="AppTheme" parent="AppBaseTheme">
<item name="android:typeface">monospace</item>
</style>
</resources>
棒棒糖（API 21）：
<resources>
<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
</style>
<!-- Application theme. -->
<style name="AppTheme" parent="AppBaseTheme">
<item name="android:textAppearance">@style/CustomTextAppearance</item>
</style>
<style name="CustomTextAppearance">
<item name="android:typeface">monospace</item>
</style>
</resources>
选项2： 将需要自定义字体的每个View子类化。ListView，EditTextView，Button等（Palani的答案）：
public class CustomFontView extends TextView {
public CustomFontView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
public CustomFontView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public CustomFontView(Context context) {
super(context);
init();
}
private void init() {
if (!isInEditMode()) {
Typeface tf = Typeface.createFromAsset(getContext().getAssets(), "Futura.ttf");
setTypeface(tf);
}
}
选项3： 实现一个遍历当前屏幕的视图层次结构的View Crawler：
变化＃1（汤姆的答案）：
public static final void setAppFont(ViewGroup mContainer, Typeface mFont, boolean reflect)
{
if (mContainer == null || mFont == null) return;
final int mCount = mContainer.getChildCount();
// Loop through all of the children.
for (int i = 0; i < mCount; ++i)
{
final View mChild = mContainer.getChildAt(i);
if (mChild instanceof TextView)
{
// Set the font if it is a TextView.
((TextView) mChild).setTypeface(mFont);
}
else if (mChild instanceof ViewGroup)
{
// Recursively attempt another ViewGroup.
setAppFont((ViewGroup) mChild, mFont);
}
else if (reflect)
{
try {
Method mSetTypeface = mChild.getClass().getMethod("setTypeface", Typeface.class);
mSetTypeface.invoke(mChild, mFont);
} catch (Exception e) { /* Do something... */ }
}
}
}
用法：
final ViewGroup mContainer = (ViewGroup) findViewById(
android.R.id.content).getRootView();
HomeActivity.setAppFont(mContainer, Typeface.createFromAsset(getAssets(),
"fonts/MyFont.ttf"));
版本2：https： //coderwall.com/p/qxxmaa/android-use-a-custom-font-everywhere。
选项4： 使用称为书法的 3rd Party Lib 。
就个人而言，我建议使用Option＃4，因为它可以省去很多麻烦。