flutter实现验证码自动填充

UI效果图

实现思路

1、使用Stack层叠布局

2、创建 4 个 Container 作为显示 4个验证码的 视图

3、创建TextField覆盖在 Container 上面 设置字体位透明颜色

 4、监听TextField 输入  填充 4 个 Container 刷新UI

具体代码如下

import 'package:flutter/material.dart';
import 'package:z_chat_flutter/tools/CustomStyle.dart';
import 'package:z_chat_flutter/tools/ImageConfig.dart';

import '../tools/ColorConfig.dart';

class CodeAutoFillWidget extends StatefulWidget {
  const CodeAutoFillWidget({Key? key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _CodeAutoFillWidget();
}

class _CodeAutoFillWidget extends State<CodeAutoFillWidget> {

  TextEditingController? control;
  //定义4个长度的验证码
  int maxWord = 4;

  @override
  void initState() {
    super.initState();
    control = TextEditingController();
  }

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    var codeText = "${control?.value.text}";
    return Container(
      height: 50,
      width: 304,
      child: Stack(
        children: [
          Row(
            children: [
              Container(
                alignment: AlignmentDirectional.center,
                width: 50,
                height: 50,
                margin: EdgeInsets.only(left: 15),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    border: Border.all(color: Color0FE9EA)),
                child: Text(
                  codeText.length > 0 ? codeText.substring(0, 1) : "",
                  style: CText(
                    s: 24.0,
                  ),
                ),
              ),
              Container(
                alignment: AlignmentDirectional.center,
                width: 50,
                height: 50,
                margin: EdgeInsets.only(left: 25),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    border: Border.all(color: Color0FE9EA)),
                child: Text(
                  codeText.length > 1 ? codeText.substring(1, 2) : "",
                  style: CText(
                    s: 24.0,
                  ),
                ),
              ),
              Container(
                alignment: AlignmentDirectional.center,
                width: 50,
                height: 50,
                margin: EdgeInsets.only(left: 25),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    border: Border.all(color: Color0FE9EA)),
                child: Text(
                  codeText.length > 2 ? codeText.substring(2, 3) : "",
                  style: CText(
                    s: 24.0,
                  ),
                ),
              ),
              Container(
                alignment: AlignmentDirectional.center,
                width: 50,
                height: 50,
                margin: EdgeInsets.only(left: 25),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    border: Border.all(color: Color0FE9EA)),
                child: Text(
                  codeText.length > 3 ? codeText.substring(3, 4) : "",
                  style: CText(
                    s: 24.0,
                  ),
                ),
              ),
            ],
          ),
          Padding(
            padding: EdgeInsets.only(left: 0),
            child: TextField(
              controller: control,
              textAlign: TextAlign.start,
              maxLength: 4,
              onChanged: (value) {
                setState(() {});
              },
              showCursor: false,
              style: TextStyle(
                color: Colors.transparent,
                fontWeight: FontWeight.bold,
                fontSize: 24,
                letterSpacing: 36,
              ),
              decoration: InputDecoration(
                  hintText: "",
                  border: InputBorder.none,
                  contentPadding: EdgeInsets.only(left: 30)),
              // )
            ),
          )
        ],
      ),
    );
  }
}