也许可以简单一点:

public class Fonts {
  public static HashSet<String,Typeface> fonts = new HashSet<>();

  public static Typeface get(Context context, String file) {
    if (! fonts.contains(file)) {
      synchronized (this) {
        Typeface typeface = Typeface.createFromAsset(context.getAssets(), name);
        fonts.put(name, typeface);
      }
    }
    return fonts.get(file);
  }
}

// Usage
Typeface myFont = Fonts.get("arial.ttf");

(请注意，此代码未经测试，但通常这种方法应该工作良好。)

以上答案是正确的。只要确保你在“assets”文件夹下创建了一个名为“fonts”的子文件夹，如果你正在使用这段代码。

它有点老，但我改进了类CustomFontLoader一点点，我想分享它，所以它可以很有帮助。只需用这段代码创建一个新类。

 import android.content.Context;
 import android.graphics.Typeface;

public enum FontLoader {

ARIAL("arial"),
TIMES("times"),
VERDANA("verdana"),
TREBUCHET("trbuchet"),
GEORGIA("georgia"),
GENEVA("geneva"),
SANS("sans"),
COURIER("courier"),
TAHOMA("tahoma"),
LUCIDA("lucida");   


private final String name;
private Typeface typeFace;


private FontLoader(final String name) {
    this.name = name;

    typeFace=null;  
}

public static Typeface getTypeFace(Context context,String name){
    try {
        FontLoader item=FontLoader.valueOf(name.toUpperCase(Locale.getDefault()));
        if(item.typeFace==null){                
            item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");                 
        }           
        return item.typeFace;
    } catch (Exception e) {         
        return null;
    }                   
}
public static Typeface getTypeFace(Context context,int id){
    FontLoader myArray[]= FontLoader.values();
    if(!(id<myArray.length)){           
        return null;
    } 
    try {
        if(myArray[id].typeFace==null){     
            myArray[id].typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+myArray[id].name+".ttf");                       
        }       
        return myArray[id].typeFace;    
    }catch (Exception e) {          
        return null;
    }   

}

public static Typeface getTypeFaceByName(Context context,String name){      
    for(FontLoader item: FontLoader.values()){              
        if(name.equalsIgnoreCase(item.name)){
            if(item.typeFace==null){
                try{
                    item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");     
                }catch (Exception e) {          
                    return null;
                }   
            }
            return item.typeFace;
        }               
    }
    return null;
}   

public static void loadAllFonts(Context context){       
    for(FontLoader item: FontLoader.values()){              
        if(item.typeFace==null){
            try{
                item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");     
            }catch (Exception e) {
                item.typeFace=null;
            }   
        }                
    }       
}   
}

然后使用这段代码在你的textview:

 Typeface typeFace=FontLoader.getTypeFace(context,"arial");  
 if(typeFace!=null) myTextView.setTypeface(typeFace);

另一种巩固字体创建的方法…

public class Font {
  public static final Font  PROXIMA_NOVA    = new Font("ProximaNovaRegular.otf");
  public static final Font  FRANKLIN_GOTHIC = new Font("FranklinGothicURWBoo.ttf");
  private final String      assetName;
  private volatile Typeface typeface;

  private Font(String assetName) {
    this.assetName = assetName;
  }

  public void apply(Context context, TextView textView) {
    if (typeface == null) {
      synchronized (this) {
        if (typeface == null) {
          typeface = Typeface.createFromAsset(context.getAssets(), assetName);
        }
      }
    }
    textView.setTypeface(typeface);
  }
}

然后在你的活动中使用…

myTextView = (TextView) findViewById(R.id.myTextView);
Font.PROXIMA_NOVA.apply(this, myTextView);

请注意，这种带有volatile字段的双重检查锁定习惯用法仅适用于Java 1.5+中使用的内存模型。

我终于找到了一个非常简单的解决方法。

use these Support libraries in app level gradle, compile 'com.android.support:appcompat-v7:26.0.2' compile 'com.android.support:support-v4:26.0.2' then create a directory named "font" inside the res folder put fonts(ttf) files in that font directory, keep in mind the naming conventions [e.g.name should not contain any special character, any uppercase character and any space or tab] After that, reference that font from xml like this <Button android:id="@+id/btn_choose_employee" android:layout_width="140dp" android:layout_height="40dp" android:layout_centerInParent="true" android:background="@drawable/rounded_red_btn" android:onClick="btnEmployeeClickedAction" android:text="@string/searching_jobs" android:textAllCaps="false" android:textColor="@color/white" android:fontFamily="@font/times_new_roman_test" />

在本例中，times_new_roman_test是该字体目录中的字体ttf文件

当你的字体存储在res/asset/fonts/Helvetica.ttf中时，使用以下方法:

Typeface tf = Typeface.createFromAsset(getAssets(),"fonts/Helvetica.ttf"); 
txt.setTypeface(tf);

或者，如果你的字体文件存储在res/font/helvetica.ttf中，使用以下方法:

Typeface tf = ResourcesCompat.getFont(this,R.font.helvetica);
txt.setTypeface(tf);