flutter TextField 键盘弹出和隐藏,限制仅英文输入, 禁止联想输入

var focusNode = FocusNode(); RegExp englishRegExp = RegExp(r'(^[a-zA-Z]*$)'); String inputText = ''; showKeyboard() { focusNode.requestFocus(); } dismissKeyboard() { focusNode.unfocus(); } getTextField() { var currentModel = currentItem(); return TextField( controller: controller, focusNode: focusNode, style: TextStyle(color: Colors.transparent), //字体透明 showCursor: false, enableInteractiveSelection: false, keyboardType: TextInputType.visiblePassword, decoration: InputDecoration( ///边框不可见 border: InputBorder.none, ), onChanged: (value) { ///禁止联想输入 var length = value.length - inputText.length; if (length > 1) { controller.value = TextEditingValue( text: inputText, selection: TextSelection.collapsed(offset: inputText.length)); return; } ///禁止非英文输入（不要用inputFormatters:[WhitelistingTextInputFormatter(xxx)]，空格输入，最后一个字符删除等有问题）； if (!englishRegExp.hasMatch(value)) { controller.value = TextEditingValue( text: inputText, selection: TextSelection.collapsed(offset: inputText.length)); return; } setState(() { ///删除键差值是-1（没有删除键的回调，只能用-1来做校验，可能会有联想输入刚好差值为-1的情况） if (length == -1 || length == 1) { inputText = value; } controller.value = TextEditingValue( text: inputText, selection: TextSelection.collapsed(offset: inputText.length)); }); ///判断是否输入完成(达到输入上限) inputWordCompleted(); }, ); }