[移动开发]Android EditText使得输入默认两位小数

       val textWatcher: TextWatcher = object : TextWatcher {
            override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
                var s = s
                if (s.toString().contains(".")) {
                    if (s.length - 1 - s.toString().indexOf(".") > 2) {
                        s = s.toString().subSequence(0,
                                s.toString().indexOf(".") + 3)
                        et_course_price.setText(s)
                        et_course_price.setSelection(s.length)
                    }
                }
                if (s.toString().trim { it <= ' ' }.substring(0) == ".") {
                    s = "0$s"
                    et_course_price.setText(s)
                    et_course_price.setSelection(2)
                }
                if (s.toString().startsWith("0")
                        && s.toString().trim { it <= ' ' }.length > 1) {
                    if (s.toString().substring(1, 2) != ".") {
                        et_course_price.setText(s.subSequence(0, 1))
                        et_course_price.setSelection(1)
                        return
                    }
                }
            }

            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int){}

            override fun afterTextChanged(s: Editable?) {}
        }
        et_course_price.addTextChangedListener(textWatcher)