flutter TextField只输入数字，包括小数,限制位数

TextField本身就可以添加一些限制条件.keyboardType: TextInputType.number,这样就只有数字和小数点了,但是在安卓里,有一些奇奇怪怪的键盘,所以我们就需要做一些判断和限制.

添加限制条件

keyboardType: TextInputType.number,
inputFormatters: [
// FilteringTextInputFormatter.digitsOnly,//数字，只能是整数
 LengthLimitingTextInputFormatter(15), //限制长度
 FilteringTextInputFormatter.allow(RegExp("[0-9.]")),//数字包括小数
//FilteringTextInputFormatter.allow(RegExp("[a-zA-Z]")),//只允许输入字母
],

限制位数,但是每次从新赋值的时候,光标都会跑到第一位去,这时候我们就需要手动把光标放到最后.priceCon.selection = TextSelection.fromPosition(TextPosition(offset: priceCon.text.length)); 这个就是移动光标的方法.也可以写在TextEditingController里.

onChanged: (value) {
  if (value.contains(".")) {
    var vv = value.split('.');
    if (vv.length > 2) {
      priceCon.text = '${vv[0]}.${vv[1]}';
    } else if (vv.length == 2) {
      if (vv[1].length > 4) {
        priceCon.text = moneyDoubleOrInt(
            double.parse(priceCon.text),
            postion: 4);
      }
    }
    priceCon.selection =
        TextSelection.fromPosition(TextPosition(
            offset: priceCon.text.length));
  }
},

全部代码

TextField(
  controller: priceCon,
  style: TextStyle(
    color: getBlackColor(),
    fontSize: SAdapt.size(15),
    fontWeight: FontWeight.bold,
    fontFamily: getSegoeUISemibold(),
  ),
  keyboardType:
      const TextInputType.numberWithOptions(
          decimal: true),
  onEditingComplete: () {
    ///点击发送调用
  },
  onChanged: (value) {
    if (value.contains(".")) {
      var vv = value.split('.');
      if (vv.length > 2) {
        priceCon.text = '${vv[0]}.${vv[1]}';
      } else if (vv.length == 2) {
        if (vv[1].length > 4) {
          priceCon.text = moneyDoubleOrInt(
              double.parse(priceCon.text),
              postion: 4);
        }
      }
      priceCon.selection =
          TextSelection.fromPosition(TextPosition(
              offset: priceCon.text.length));
    }
  },
  decoration: InputDecoration(
    hintText: 'Price'.tr,
    hintStyle: TextStyle(
      color: get999999Color(),
      fontSize: SAdapt.size(15),
      fontWeight: FontWeight.w400,
      fontFamily: getSegoeUISemibold(),
    ),
    isDense: true,
    contentPadding: EdgeInsets.only(
        left: SAdapt.width(17.5),
        top: 5,
        bottom: 5,
        right: 10),
    border: const OutlineInputBorder(
      gapPadding: 0,
      borderSide: BorderSide(
        width: 0,
        style: BorderStyle.none,
      ),
    ),
  ),
  inputFormatters: [
    LengthLimitingTextInputFormatter(15), //限制长度
    FilteringTextInputFormatter.allow(
        RegExp("[0-9.]")),
  ],
  // minLines: 1,
),