Flutter中首字符限制为“0”

Question

如何限制在Flutter的文本框中不应该将“0”放在第一个字符位置？下面是示例dart代码。

TextField(
                                          inputFormatters: <TextInputFormatter>[
                                            FilteringTextInputFormatter.allow(
                                                RegExp("[0-9\u0660-\u0669]")),
                                          ],
                                          keyboardType: TextInputType.number,
                                          focusNode: _nodeText1,
                                          controller: mobileNumber,
                                          decoration: InputDecoration.collapsed(
                                              fillColor: TuxedoColor.whiteColor,
                                              hintText: "5xxxxxxxx"),
                                        ),

- Mohammed Nabil

Answer 1

使用此代码：

   inputFormatters: <TextInputFormatter>[
                                FilteringTextInputFormatter.allow(
                                  RegExp(r'[0-9]'),
                                ),
                                FilteringTextInputFormatter.deny(
                                  RegExp(
                                      r'^0+'), //users can't type 0 at 1st position
                                ),
                              ],

- Arijeet

Answer 2

尝试使用以下代码，使用 FilteringTextInputFormatter.deny：

TextField(
      inputFormatters: <TextInputFormatter>[
        FilteringTextInputFormatter.allow(RegExp("[0-9\u0660-\u0669]")),
        FilteringTextInputFormatter.deny(RegExp(r'^0+')),
      ],
      keyboardType: TextInputType.number,
      decoration: InputDecoration.collapsed(hintText: "5xxxxxxxx"),
    ),

- Ravindra S. Patil