How to set custom typeface to items in NavigationView?

just add following class file to your project.

import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.TextPaint;
import android.text.style.TypefaceSpan;

public class CustomTypefaceSpan extends TypefaceSpan {

    private final Typeface newType;

    public CustomTypefaceSpan(String family, Typeface type) {
        super(family);
        newType = type;
    }

    @Override
    public void updateDrawState(TextPaint ds) {
        applyCustomTypeFace(ds, newType);
    }

    @Override
    public void updateMeasureState(TextPaint paint) {
        applyCustomTypeFace(paint, newType);
    }

    private static void applyCustomTypeFace(Paint paint, Typeface tf) {
        int oldStyle;
        Typeface old = paint.getTypeface();
        if (old == null) {
            oldStyle = 0;
        } else {
            oldStyle = old.getStyle();
        }

        int fake = oldStyle & ~tf.getStyle();
        if ((fake & Typeface.BOLD) != 0) {
            paint.setFakeBoldText(true);
        }

        if ((fake & Typeface.ITALIC) != 0) {
            paint.setTextSkewX(-0.25f);
        }

        paint.setTypeface(tf);
    }
}

then create following method to your activity

private void applyFontToMenuItem(MenuItem mi) {
        Typeface font = Typeface.createFromAsset(getAssets(), "ds_digi_b.TTF");
        SpannableString mNewTitle = new SpannableString(mi.getTitle());
        mNewTitle.setSpan(new CustomTypefaceSpan("" , font), 0 , mNewTitle.length(),  Spannable.SPAN_INCLUSIVE_INCLUSIVE);
        mi.setTitle(mNewTitle);
}

and call it from activity.

navView = (NavigationView) findViewById(R.id.navView);
        Menu m = navView.getMenu();
        for (int i=0;i<m.size();i++) {
            MenuItem mi = m.getItem(i);

            //for aapplying a font to subMenu ...
            SubMenu subMenu = mi.getSubMenu();
            if (subMenu!=null && subMenu.size() >0 ) {
                for (int j=0; j <subMenu.size();j++) {
                    MenuItem subMenuItem = subMenu.getItem(j);
                    applyFontToMenuItem(subMenuItem);
                }
            }

            //the method we have create in activity
            applyFontToMenuItem(mi);
        }

and here is my output