更改表单中 TextFormField 的键盘类型

Question

我有一个接受字母和数字的文本表单，键盘会动态变化。它工作正常，但是当我删除代码时，数字键盘仍然存在这是示例

    final _controller = TextEditingController();
    var keyboardType = TextInputType.text;
    FocusNode _focusNode = FocusNode();
    
TextFormField(
    style: TextStyle(
    color: Colors.black,
    fontSize: 50,
    fontWeight: FontWeight.w700),
     decoration:
    InputDecoration(labelText: "code", hintText: 'ABC1234'),
    controller: _controller,
    focusNode: _focusNode,
    textCapitalization: TextCapitalization.characters,
    keyboardType: keyboardType,
    onChanged: (value) {
     if (value.length == 3) {
    FocusScope.of(context).unfocus();
     setState(() {
     keyboardType = TextInputType.number;
    });
    
     Future.delayed(Duration(milliseconds: 150)).then((value) {
     FocusScope.of(context).requestFocus();
    
    });
       } else {
        setState(() {
     keyboardType = TextInputType.text;
       });
       }
      }),

Answer 1

那是因为它已经开放了。您将必须执行与将其显示为数字键盘相同的步骤

即

else {
FocusScope.of(context).unfocus();
 setState(() {
 keyboardType = TextInputType.text;
});

 Future.delayed(Duration(milliseconds: 150)).then((value) {
 FocusScope.of(context).requestFocus();

});

另外，这种处理条件的方式在很多情况下会导致键盘的关闭和重新打开，您应该按如下方式进行

if (value.length == 3 && keyboardType == TextInputType.text) {
//....
} else if (value.length < 3 && keyboardType != TextInput.text) {

更改表单中 TextFormField 的键盘类型

Change the keyboard type for a TextFormField in a Form

dart

flutter