展示效果：

image.png

/**
 * 將給定的字符串給定的長度兩端對齊
 *
 * @param str 待對齊字符串
 * @param size 漢字個數(shù)，eg:size=5，則將str在5個漢字的長度里兩端對齊
 * @param isAddColon 是否添加冒號
 * @return 調(diào)整后的字符串
 */
public static SpannableStringBuilder justifyString(String str, int size, boolean isAddColon) {
    SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder();
    if (TextUtils.isEmpty(str)) {
        return spannableStringBuilder;
    }
    char[] chars = str.toCharArray();
    if (chars.length >= size || chars.length == 1) {
        spannableStringBuilder.append(str);
        if (isAddColon){
            spannableStringBuilder.append("：");
        }
        return spannableStringBuilder;
    }
    int l = chars.length;
    float scale = (float) (size - l) / (l - 1);
    for (int i = 0; i < l; i++) {
        spannableStringBuilder.append(chars[i]);
        if (i != l - 1) {
            // 全角空格;
            SpannableString s = new SpannableString("　");
            s.setSpan(new ScaleXSpan(scale), 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            spannableStringBuilder.append(s);
        }
    }
    if (isAddColon){
        spannableStringBuilder.append("：");
    }
    return spannableStringBuilder;
}