EditText相关-

catchphrase.addTextChangedListener(object:TextWatcher{
            override fun afterTextChanged(s: Editable?) {
                if(s?.length?:0>20){
                    KApp.toast(R.string.share_edit_number_over100)
                    catchphrase.setText(catchphrase.text.toString().substring(0,20))
                    catchphrase.setSelection(catchphrase.text.toString().length)
                }
            }

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

            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            }

        })

设置输入类型为数字

extendEdit.inputType = EditorInfo.TYPE_CLASS_NUMBER

限制输入字数

extendEdit.setFilters(arrayOf(InputFilter.LengthFilter(length)))