flutter TextFormField验证显示对齐错误

Question

我有一个 TextFormField 验证为空。

为了控制高度，TextFormField 嵌套在 Container 小部件中。

这会导致显示错误消息与附加图片重叠的意外副作用。

要测试示例代码，请按“提交”查看错误。

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: SimpleForm(),
    );
  }
}

class SimpleForm extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final formKey = GlobalKey<FormState>();
    return SafeArea(
      child: Scaffold(
//          primary: true,
          body: Form(
            key: formKey,
            child: Column(
              children: [
                SizedBox(
                  height: 0,
                ),
//            Container(height: 0,),
                Container(
                  height: 38,
                  margin: EdgeInsets.all(6),
                  child: TextFormField(
                    maxLines: 1,
                    decoration: InputDecoration(
                      border: OutlineInputBorder(),
                      hintText: 'Name',
//                  errorStyle: TextStyle(fontSize: 0, height: 0),
                    ),
                    validator: (value) => (value.isEmpty) ? '**' : null,
                  ),
                ),
                FlatButton(
                  child: Text('Submit'),
                  onPressed: () {
                    formKey.currentState.validate();
                  },
                )
              ],
            ),
          )),
    );
  }
}

Answer 1

你可以用这个

   TextFormField(
  decoration: new InputDecoration(
  enabledBorder: OutlineInputBorder(                     //change border of enable textfield
  borderRadius: BorderRadius.all(Radius.circular(40.0)),
  borderSide: BorderSide(color: colorValue),),
        focusedBorder: OutlineInputBorder(        //focus boarder
          borderRadius: BorderRadius.all(Radius.circular(40.0)),
          borderSide: BorderSide(color: colorValue),
        ),
                 focusedBorder: OutlineInputBorder(
      borderRadius: BorderRadius.all(Radius.circular(4)),
      borderSide: BorderSide(width: 1,color: Colors.red),
    ),
    disabledBorder: OutlineInputBorder(
      borderRadius: BorderRadius.all(Radius.circular(4)),
      borderSide: BorderSide(width: 1,color: Colors.orange),
    ),
    enabledBorder: OutlineInputBorder(
      borderRadius: BorderRadius.all(Radius.circular(4)),
      borderSide: BorderSide(width: 1,color: Colors.green),
    ),
    border: OutlineInputBorder(
      borderRadius: BorderRadius.all(Radius.circular(4)),
      borderSide: BorderSide(width: 1,)
    ),
    errorBorder: OutlineInputBorder(.                              //error boarder
      borderRadius: BorderRadius.all(Radius.circular(4)),
      borderSide: BorderSide(width: 1,color: Colors.black)
    ),

        isDense: true,
        counterText: "",
        contentPadding: EdgeInsets.fromLTRB(10, 20, 10, 0),  //padding according to your need
        hintText: "create new",
        hintStyle: TextStyle(color: colorValue, fontSize: 13)),
  )),

Answer 2

解决方案1.可以为TextField的decoration设置helperText，增加Container的身高：

Container(
  height: 60,
  child: TextFormField(
    maxLines: 1,
    decoration: InputDecoration(
      border: OutlineInputBorder(),
      hintText: 'Name',
      helperText: ' ', // this is new
    ),
    validator: (value) => (value.isEmpty) ? '**' : null,
  ),
),

解决方法2.可以将报错信息的行高设置为0（会显示在文本框上方）：

Container(
  height: 38,
  child: TextFormField(
    maxLines: 1,
    decoration: InputDecoration(
      border: OutlineInputBorder(),
      hintText: 'Name',
      errorStyle: TextStyle(height: 0), // this is new
    ),
    validator: (value) => (value.isEmpty) ? '**' : null,
  ),
),

Answer 3

感谢您的回答Mobina,

问题似乎是 flutter 限制。暂时..

带边框我决定在顶部显示错误消息。（您的解决方案：1）

没有边框我可以像往常一样显示错误信息。（您的解决方案：2）

// with border
            Container(
              height: 38,
              margin: EdgeInsets.all(6),
              child: TextFormField(
                textAlignVertical: TextAlignVertical.bottom,
                style: TextStyle(fontSize: 14),
                decoration: InputDecoration(
                  border: OutlineInputBorder(),
                  hintText: 'Name',
                  errorStyle: TextStyle(height: 0),
                ),
                validator: (value) => (value.isEmpty) ? 'hide overlap' : null,
              ),
            ),
// without border
            Container(
              height: 38,
              margin: EdgeInsets.all(6),
              child: TextFormField(
                textAlignVertical: TextAlignVertical.bottom,
                style: TextStyle(fontSize: 14),
                decoration: InputDecoration(
                  hintText: 'Name',
                  helperText: ' ',   isDense: true,
                  counterText: "",
                  contentPadding: EdgeInsets.fromLTRB(10, 30, 10, 0),
                ),
                validator: (value) => (value.isEmpty) ? 'hide overlap' : null,
              ),
            ),

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