Android 自定义TextView 更改字体

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qin_shi/article/details/83717699

前言

项目中经常使用到自定义字体，如果每个都在代码中进行设置，就会比较麻烦，所以采用在xml中直接自定以设置字体。
最终调用效果：

  xmlns:app="http://schemas.android.com/apk/res-auto"
  //通过app:typeface 设置字体
  <americanshop.com.americanshop.view.AppTextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:typeface="sf_pro_regular" />

步骤

1. 把字体添加到assets目录下。
   

2. 修改atters.xml文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="CustomTextView">
        <attr name="typeface">
            <enum name="sf_pro_bold" value="0"/>
            <enum name="sf_pro_bold_italic" value="1"/>
            <enum name="sf_pro_heavy" value="2"/>
        </attr>
    </declare-styleable>
    </resources>

attr 的name 即是在xml时用的标签，declare-styleable 的name 用于获取在xml中设置的typeface值。

3. 创建自定义TextView

public class AppTextView extends AppCompatTextView {
	public static class TypefaceValue{
		public static final int Bold = 0;
		public static final int BoldItalic = 1;
		public static final int Heavy = 2;
	}

	@IntDef({TypefaceValue.Bold, TypefaceValue.BoldItalic, TypefaceValue.Heavy})
	@Retention(RetentionPolicy.SOURCE)
	public @interface TypeFace {
	}

	public AppTextView(Context context) {
		this(context,null);
	}

	public AppTextView(Context context, AttributeSet attrs) {
		this(context, attrs,0);
	}

	public AppTextView(Context context, AttributeSet attrs, int defStyleAttr) {
		super(context, attrs, defStyleAttr);
		init(context,attrs);
	}

	private void init(Context context, AttributeSet attrs) {
		Typeface typeface = null;
		if (!isInEditMode()){
			if(null != attrs){
			TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomTextView);
			typeface = typefaceFromAttrs(context,a);
			a.recycle();
			}
			if (typeface == null){
				typeface = FontUtils.getSFProRegular();
			}
			setTypeface(typeface);
		}
	}

	private Typeface typefaceFromAttrs(Context context, TypedArray a) {
		Typeface typeface = null;
		if (a.hasValue(R.styleable.CustomTextView_typeface)) {
			int typefaceValue = a.getInt(R.styleable.CustomTextView_typeface, TypefaceValue.Regular);
			switch (typefaceValue) {
				case TypefaceValue.Bold:
					typeface = FontUtils.getSFProBold();
					break;
				case TypefaceValue.BoldItalic:
					typeface = FontUtils.getSFProBoldItalic();
					break;
				case TypefaceValue.Heavy:
					typeface = FontUtils.getSFProHeavy();
					break;
				default:
					typeface = FontUtils.getSFProRegular();
			}
		}
		if (typeface == null) {
			typeface = FontUtils.getSFProRegular();
		}
		return typeface;
	}
}

4. FontUtils封装了对font的读取

public class FontUtils {

    private static final Map<String, Typeface> fontMap = new HashMap();
    private static Typeface getFontTypefaceFromAssert(String fontName) {
        try {
            synchronized (fontMap) {
                if (!fontMap.containsKey(fontName)) {
                    Typeface typface = Typeface.createFromAsset(App.getAppComponent().getContext().getAssets(), fontName);
                    fontMap.put(fontName, typface);
                }
                Typeface typface = fontMap.get(fontName);
                return typface;
            }
        } catch (Exception e) {
            return null;
        }
    }

    public static Typeface getFontTypefaceByName(String fontName) {
        return getFontTypefaceFromAssert(fontName);
    }

    public static Typeface getSFProBold() {
        return getFontTypefaceFromAssert("fonts/SF-Pro-Text-Bold.otf");
    }

    public static Typeface getSFProBoldItalic() {
        return getFontTypefaceFromAssert("fonts/SF-Pro-Text-BoldItalic.otf");
    }
    static public void changeFont(View element, Typeface tf){
        if (element instanceof TextView) {
            ((TextView) element).setTypeface(tf);
        }else if(element instanceof EditText){
            ((EditText)element).setTypeface(tf);
        }
    }
}