flutter - 如何在不显示键盘的情况下聚焦 TextField？

Question

我需要专注于 TextField 但不显示键盘。仅当用户点击 TextField时才需要显示键盘。

我尝试了两种方法。

第一次尝试：

这样键盘就会显示出来，并且在屏幕构建后隐藏起来，这不太好看。

生成器：

TextFormField(
    controller: barcodeStringController,
    focusNode: myFocusNode,
    autofocus: true,
    textAlign: TextAlign.right,
    textInputAction: TextInputAction.done,
    textCapitalization: TextCapitalization.characters,
    style: TextStyle(fontSize: 20),
    maxLines: null,
    onTap: () {
      SystemChannels.textInput.invokeMethod('TextInput.show');
    },
    //... Other event listeners to handle submit
),

并且在构建（）之外：

void _onAfterBuild(BuildContext context) {
  SystemChannels.textInput.invokeMethod('TextInput.hide');
}

第二次尝试：

这样键盘就被隐藏在了一个较低的层次，而且更容易看到。问题是永远不会调用 onTap，因此键盘永远不会显示，onTap 也不会。

生成器：

GestureDetector(
    onTap: () {
        SystemChannels.textInput.invokeMethod('TextInput.show');
    },
    child: TapOnlyFocusTextField(
        controller: barcodeStringController,
        focusNode: myFocusNode, //this is a TapOnlyFocusTextFieldFocusNode
        textAlign: TextAlign.right,
        textInputAction: TextInputAction.done,
        textCapitalization: TextCapitalization.characters,
        style: TextStyle(fontSize: 20),
        cursorColor: Colors.black,
        //... Other event listeners to handle submit
    ),
),

TapOnlyFocusTextField 类：

class TapOnlyFocusTextField extends EditableText {
  TapOnlyFocusTextField({
    @required TextEditingController controller,
    @required TextStyle style,
    @required Color cursorColor,
    bool autofocus = false,
    Color selectionColor,
    FocusNode focusNode,
    TextAlign textAlign,
    TextInputAction textInputAction,
    TextCapitalization textCapitalization,
    onSubmitted,
    onChanged,
  }) : super(
          controller: controller,
          focusNode: focusNode,
          style: style,
          cursorColor: cursorColor,
          autofocus: autofocus,
          selectionColor: selectionColor,
          textAlign: textAlign,
          textInputAction: textInputAction,
          textCapitalization: textCapitalization,
          maxLines: null,
          onSubmitted: onSubmitted,
          backgroundCursorColor: Colors.black,
          onChanged: onChanged,
        );

  @override
  EditableTextState createState() {
    return TapOnlyFocusTextFieldState();
  }
}

class TapOnlyFocusTextFieldState extends EditableTextState {
  @override
  void requestKeyboard() {
    super.requestKeyboard();
    //hide keyboard
    SystemChannels.textInput.invokeMethod('TextInput.hide');
  }
}

TapOnlyFocusTextFieldFocusNode 类：

class TapOnlyFocusTextFieldFocusNode extends FocusNode {
  @override
  bool consumeKeyboardToken() {
    // prevents keyboard from showing on first focus
    return false;
  }
}

我知道 Flutter Github 中已经有一个未解决的问题，但我需要找到解决方案： https ://github.com/flutter/flutter/issues/16863

标签： flutterdart

Answer 1

如此处所示：https ://stackoverflow.com/a/60392327/4693979

但我更喜欢在 initState 中执行此操作：

  void initState() {
    super.initState();
    Future.delayed(
      Duration(),
      () => SystemChannels.textInput.invokeMethod('TextInput.hide'),
    );
  }

不要忘记将自动对焦设置为 true。