关于给textview设置字体间的间距

通过自定义textview实现方法如下

public class MTextView extends TextView{

    private float spacing = Spacing.NORMAL;
    private CharSequence originalText = "";

    public MTextView(Context context) {
        super(context);
    }

    public MTextView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public MTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    /*
    * 通过自定义属性来实现
    * */
    private void init(Context context, AttributeSet attrs) {
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.LetterSpacingTextView);
        originalText = array.getString(R.styleable.LetterSpacingTextView_text);
        setSpacing(array.getFloat(R.styleable.LetterSpacingTextView_textSpacing, 0));
        array.recycle();
    }
    public float getSpacing() {
        return this.spacing;
    }


    public void setSpacing(float spacing) {
        this.spacing = spacing;
        applySpacing();
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        originalText = text;
        applySpacing();
    }

    @Override
    public CharSequence getText() {
        return originalText;
    }
    private void applySpacing() {
        if (this == null || this.originalText == null) return;
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < originalText.length(); i++) {
            builder.append(originalText.charAt(i));
            if (i + 1 < originalText.length()) {
                builder.append("\u00A0");
            }
        }
        SpannableString finalText = new SpannableString(builder.toString());
        if (builder.toString().length() > 1) {
            for (int i = 1; i < builder.toString().length(); i += 2) {
                finalText.setSpan(new ScaleXSpan((spacing + 1) / 10), i, i + 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
        super.setText(finalText, BufferType.SPANNABLE);
    }

    public class Spacing {
        public final static float NORMAL = 0;
    }

 在values文件夹下对应的attrs文件为

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="LetterSpacingTextView">
        <attr name="textSpacing" format="float"/>
        <attr name="text" format="string"/>
    </declare-styleable>
</resources>

在xml文件中的使用

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:zch="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >

   <com.xt.cq3000.view.MTextView
       android:textSize="23sp"
       zch:text="这是一段很长的文字哦"
       zch:textSpacing="5"
       android:background="@drawable/txt_click_selector"
       android:clickable="true"
       android:layout_width="140dp"
       android:layout_height="140dp"
       android:gravity="center"
       android:layout_centerInParent="true"
       android:textColor="#ffffff"/>

</RelativeLayout>