android架构师之路——修改app字体

android自带的字体

通过 android:typeface="normal" 或者 android:fontFamily="monospace"两种方式来设置字体，两者区别在于android:fontFamily是API16以后增加

具体字体样式可以参考下图

通过ttf自定义字体

在assets下新建一个fonts文件，把字体样式文件放进去

实现代码如下

/*** 自定义字体*/private void setMyFont() {TextView ttfTextView = findViewById(R.id.text_ttf);AssetManager mgr = getAssets();Typeface tf = Typeface.createFromAsset(mgr, "fonts/specified.ttf");ttfTextView.setTypeface(tf);}

批量修改字体

public class CustomTextView extends TextView
{public CustomTextView(Context context, AttributeSet attrs){super(context, attrs);}//重写设置字体方法@Overridepublic void setTypeface(Typeface tf){tf = Typeface.createFromAsset(getContext().getAssets(), "fonts/specified.ttf");super.setTypeface(tf);}
}

全局修改字体

全局修改原理，可以参考hongyang的博客

我们可以看一下setcontentview的源码，我这里是基于API28

   public void setContentView(@LayoutRes int layoutResID) {this.getDelegate().setContentView(layoutResID);}

进入this.getDelegate().setContentView

    public void setContentView(int resId) {this.ensureSubDecor();ViewGroup contentParent = (ViewGroup)this.mSubDecor.findViewById(16908290);contentParent.removeAllViews();LayoutInflater.from(this.mContext).inflate(resId, contentParent);this.mOriginalWindowCallback.onContentChanged();}

可以看出也是通过LayoutInflater.from(this.mContext).inflate(resId, contentParent);来加载的布局

下面这图，就是LayoutInflater.from(this.mContext).inflate(resId, contentParent)与factory的关系

我们截取最后一段代码

if (mFactory2 != null) {view = mFactory2.onCreateView(parent, name, context, attrs);} else if (mFactory != null) {view = mFactory.onCreateView(name, context, attrs);} else {view = null;}

所以我们可以调用LayoutInflaterCompat.setFactory2设置mFactory2 以达到调用我们重写的onCreateView

      LayoutInflaterCompat.setFactory2(LayoutInflater.from(this), new LayoutInflater.Factory2() {@Overridepublic View onCreateView(View parent, String name, Context context, AttributeSet attrs) {Log.e(TAG,"name= "+name);int n = attrs.getAttributeCount();for (int i = 0; i < n; i++) {Log.d(TAG,attrs.getAttributeName(i) + " , " + attrs.getAttributeValue(i));}return null;}@Overridepublic View onCreateView(String name, Context context, AttributeSet attrs) {return null;}});

可以看到的输出日志

E/MainActivity: name= TextView
D/MainActivity: layout_width , -2
D/MainActivity: layout_height , -2
D/MainActivity: text , serif-monospace 字体
D/MainActivity: fontFamily , serif-monospace

所以我们只需要在这里修改字体，就可以达到统一修改字体的目的，最终代码如下

    /*** 设置整体字体*/private void setTotalTypeFace() {if (typeface == null) {typeface = Typeface.createFromAsset(getAssets(), "fonts/specified.ttf");}LayoutInflater layoutInflater = LayoutInflater.from(this);try {Field mFactorySet = LayoutInflater.class.getDeclaredField("mFactorySet");mFactorySet.setAccessible(true);mFactorySet.setBoolean(layoutInflater, false);} catch (Exception e) {e.printStackTrace();}layoutInflater.setFactory2(new LayoutInflater.Factory2() {@Overridepublic View onCreateView(View parent, String name, Context context, AttributeSet attrs) {Log.e(TAG, "name= " + name);View view = getDelegate().createView(parent, name, context, attrs);//所以这里创建 View,从而修改View属性Log.e(TAG, "view = " + view);if (view instanceof TextView) {((TextView) view).setTypeface(typeface);}int n = attrs.getAttributeCount();for (int i = 0; i < n; i++) {Log.d(TAG, attrs.getAttributeName(i) + " , " + attrs.getAttributeValue(i));}return view;}@Overridepublic View onCreateView(String name, Context context, AttributeSet attrs) {return null;}});}

总结

修改字体大致流程就是这样，总共有四种方式

通过textview的android:typeface="normal"设置字体
通过textview的android:fontFamily="serif"设置字体
通过加载fonts/specified.ttf文件，调用setTypeface设置
在BaseActivity统一设置字体，需要每一个activity集成这个BaseActivity
在application里面通过registerActivityLifecycleCallbacks注册ActivityLifecycleCallbacks，然后在onActivityCreated方法中统一修改字体

这五种方式，都在demo中加以体现了，第四种与第五种都是全局修改字体，任选其一

demo下载