inputTextForm 字段和底部边框之间的颤动空间

Question

除了元素/用户输入和底栏之间的空间外，一切正常。我尝试了不同的方法来摆脱那个空间：内容填充、框约束、前缀图标约束等。没有一个工作。最终我限制了这个小部件的高度，但随后我的错误消息被放置在用户输入之上，我收到了这条消息Another exception was thrown: BoxConstraints has a negative minimum height.
代码如下：

 Widget _emailField(FormBloc formBloc) {
    return StreamBuilder(
        stream: formBloc.email,
        builder: (context, AsyncSnapshot<String> snapshot) {
          return TextFormField(
            autofocus: false,
            keyboardType: TextInputType.emailAddress,
            autovalidateMode: AutovalidateMode.onUserInteraction,
            validator: (value) {
              if (value == null) {
                return "Email cannot be empty";
              } else {
                if (value.isEmpty) {
                  return "Email cannot be empty";
                }
              }
            },
            onChanged: formBloc.changeEmail,
            textInputAction: TextInputAction.next,
            decoration: InputDecoration(
              prefixIcon: const Icon(
                Icons.email,
                size: 15,
              ),
              contentPadding: const EdgeInsets.all(0),
              labelText: "Email",
              labelStyle: const TextStyle(fontSize: 14),
              errorText:
                  snapshot.error != null ? snapshot.error as String : null,
            ),
          );
        }
      );
  }

我需要让一切都像以前一样工作，除了这次我确实需要在底部边框和输入元素之间没有空间，我该怎么做？

Answer 1

首先进入InputDecoration()，您可以将zero padding 给您的prefix icon。 然后将prefixIconConstraints 设置为BoxConstraints(maxHeight:0) 仍然不够你可以给contentPadding: EdgeInsets.only(bottom:-5), 负值。

InputDecoration(
          prefixIcon: Padding(
            padding: EdgeInsets.only(right:10),
            child:const Icon(
              Icons.email,
              size: 15,
            ),
          ),
          prefixIconConstraints: BoxConstraints(maxHeight:0),
          contentPadding: EdgeInsets.only(bottom:-5),
          labelText: "Email",
          labelStyle: const TextStyle(fontSize: 14),
          errorText:"error",
        )