Android studio中TextView改变字体的两种方式（如仿宋、隶书）

在Android中系统默认的字体有三种，通过在TextView中加上android:typeface=”sans”来改变，而sans就是三种当中的其中的一种，还有两种分别是“monospace”和“serif”；当我们不想用着三种方式的话还可以使用外在的字体—–导入字体文件

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使用外在字体的方式有很多，下面简单分享一下使用外在字体其中的两种方式，效果图：

第一种方式：在代码中定义TextView的字体
步骤：
1、我们首先在src/main文件下创建assets文件夹，为了规范起见，我们再在assets文件夹下创建font文件夹，然后将我们的字体文件(*.ttf)放进fonts文件夹下，如图所示：

2、在我们的布局文件中做准备工作，拖入一个TextView控件

3、在代码中找到我们导进来的字体并在TextView上使用

效果：

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第二种方式：写一个类继承TextView，所有的东西都放入到这个类里面，在要用到换字体的地方就使用这个类
步骤：
1，新建一个类，让这个类继承TextView

/**
 * 1.version:
 * 2.date:2017/1/13 15:26
 * 3.update:2017/1/13.
 * 4.autour:张玉杰
 */

import android.content.Context;
import android.content.res.TypedArray;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.widget.TextView;

/**
 * Created by Administrator on 2015/10/27.
 */
public class FontTextView extends TextView {
    /** The file name of the font data in the assets directory*/
    private String mFontPath = null;

    public FontTextView(Context context) {
        super(context);
        init(context, null, 0);
    }
    public FontTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }
    public FontTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    public String getFontPath() {
        return mFontPath;
    }

    /**
     * 
Set font file fontPath
     * @param fontPath The file name of the font data in the assets directory
     */
    public void setFontPath(String fontPath) {
        mFontPath = fontPath;

        if (!TextUtils.isEmpty(mFontPath)) {
            FontUtils.getInstance().replaceFontFromAsset(this, mFontPath);
        }
    }

    private void init(Context context, AttributeSet attrs, int defStyleAttr) {
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.FontTextView, defStyleAttr, 0);
        mFontPath = typedArray.getString(R.styleable.FontTextView_font_path);
        typedArray.recycle();

        if (!TextUtils.isEmpty(mFontPath)) {
            FontUtils.getInstance().replaceFontFromAsset(this, mFontPath);
        }
    }
}

2、在写一个类用来选择字体

/**
 * 1.version:
 * 2.date:2017/1/13 15:27
 * 3.update:2017/1/13.
 * 4.autour:张玉杰
 */

import android.content.Context;
import android.graphics.Typeface;
import android.support.annotation.NonNull;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.lang.ref.SoftReference;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;

public class FontUtils {
    private static final String TAG = FontUtils.class.getSimpleName();
    private Map> mCache = new HashMap<>();
    private static FontUtils sSingleton = null;

    public static Typeface DEFAULT = Typeface.DEFAULT;

    // disable instantiate
    private FontUtils() {
    }

    public static FontUtils getInstance() {
        // double check
        if (sSingleton == null) {
            synchronized (FontUtils.class) {
                if (sSingleton == null) {
                    sSingleton = new FontUtils();
                }
            }
        }
        return sSingleton;
    }

    public void replaceFontFromAsset(@NonNull View root, @NonNull String fontPath) {
        replaceFont(root, createTypefaceFromAsset(root.getContext(), fontPath));
    }

    public void replaceFontFromAsset(@NonNull View root, @NonNull String fontPath, int style) {
        replaceFont(root, createTypefaceFromAsset(root.getContext(), fontPath), style);
    }

    public void replaceFontFromFile(@NonNull View root, @NonNull String fontPath) {
        replaceFont(root, createTypefaceFromFile(fontPath));
    }

    public void replaceFontFromFile(@NonNull View root, @NonNull String fontPath, int style) {
        replaceFont(root, createTypefaceFromFile(fontPath), style);
    }

    private void replaceFont(@NonNull View root, @NonNull Typeface typeface) {
        if (root == null || typeface == null) {
            return;
        }

        if (root instanceof TextView) { // If view is TextView or it's subclass, replace it's font
            TextView textView = (TextView) root;
            // Extract previous style of TextView
            int style = Typeface.NORMAL;
            if (textView.getTypeface() != null) {
                style = textView.getTypeface().getStyle();
            }
            textView.setTypeface(typeface, style);
        } else if (root instanceof ViewGroup) { // If view is ViewGroup, apply this method on it's child views
            ViewGroup viewGroup = (ViewGroup) root;
            for (int i = 0; i < viewGroup.getChildCount(); ++i) {
                replaceFont(viewGroup.getChildAt(i), typeface);
            }
        } // else return
    }

    private void replaceFont(@NonNull View root, @NonNull Typeface typeface, int style) {
        if (root == null || typeface == null) {
            return;
        }
        if (style < 0 || style > 3) {
            style = Typeface.NORMAL;
        }

        if (root instanceof TextView) { // If view is TextView or it's subclass, replace it's font
            TextView textView = (TextView) root;
            textView.setTypeface(typeface, style);
        } else if (root instanceof ViewGroup) { // If view is ViewGroup, apply this method on it's child views
            ViewGroup viewGroup = (ViewGroup) root;
            for (int i = 0; i < viewGroup.getChildCount(); ++i) {
                replaceFont(viewGroup.getChildAt(i), typeface, style);
            }
        } // else return
    }

    private Typeface createTypefaceFromAsset(Context context, String fontPath) {
        SoftReference typefaceRef = mCache.get(fontPath);
        Typeface typeface = null;
        if (typefaceRef == null || (typeface = typefaceRef.get()) == null) {
            typeface = Typeface.createFromAsset(context.getAssets(), fontPath);
            typefaceRef = new SoftReference<>(typeface);
            mCache.put(fontPath, typefaceRef);
        }
        return typeface;
    }

    private Typeface createTypefaceFromFile(String fontPath) {
        SoftReference typefaceRef = mCache.get(fontPath);
        Typeface typeface = null;
        if (typefaceRef == null || (typeface = typefaceRef.get()) == null) {
            typeface = Typeface.createFromFile(fontPath);
            typefaceRef = new SoftReference<>(typeface);
            mCache.put(fontPath, typefaceRef);
        }
        return typeface;
    }

    public void replaceSystemDefaultFontFromAsset(@NonNull Context context, @NonNull String fontPath) {
        replaceSystemDefaultFont(createTypefaceFromAsset(context, fontPath));
    }

    public void replaceSystemDefaultFontFromFile(@NonNull Context context, @NonNull String fontPath) {
        replaceSystemDefaultFont(createTypefaceFromFile(fontPath));
    }

    private void replaceSystemDefaultFont(@NonNull Typeface typeface) {
        modifyObjectField(null, "MONOSPACE", typeface);
    }

    private void modifyObjectField(Object obj, String fieldName, Object value) {
        try {
            Field defaultField = Typeface.class.getDeclaredField(fieldName);
            defaultField.setAccessible(true);
            defaultField.set(obj, value);

        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
}

3、在布局文件里面直接用上类的全类名，这样在实时视图里面就能看到效果

效果图：

项目地址：
http://download.csdn.net/detail/lanrenxiaowen/9737027