flutter 数字键盘、自定义键盘

有些特殊的场景 会遇到使用数字键盘的特殊场景，例如输入金额、数量

number_keypan.dart =》文件内容如下：


import 'package:flutter/material.dart';

/// <summary>
/// todo: 数字键盘
/// author：zwb
/// dateTime：2021/7/19 10:25
/// filePath：lib/widgets/number_keypan.dart
/// desc: 示例
/// <summary>
// OverlayEntry overlayEntry;
// TextEditingController controller = TextEditingController();
//
// numberKeypan(
//   initialization: (v){
//     /// 初始化
//     overlayEntry = v;
//     /// 唤起键盘
//     openKeypan(context: context);
//   },
//   onDel: (){
//     delCursor(textEditingController: controller);
//   },
//   onTap: (v){
//     /// 更新输入框的值
//     controller.text += v;
//     /// 保持光标
//     lastCursor(textEditingController: controller);
//   },
// );
OverlayEntry overlayEntry;
NumberKeypan({@required Function(OverlayEntry) initialization,@required Function(String) onTap,Function onCommit,Function onDel,}){
  overlayEntry = OverlayEntry(builder: (context) {
    List<String> list = ['1','2','3','4','5','6','7','8','9','','0','删除'];
    return new Positioned(
        bottom: 0,
        child: new Material(
          child: new Container(
            width: MediaQuery.of(context).size.width,
            alignment: Alignment.center,
            color: Colors.grey[200],
            child: Row(
              children: [
                Expanded(
                  child: Wrap(
                    alignment: WrapAlignment.spaceBetween,
                    children: List.generate(list.length, (index) {
                      return Material(
                        color: Colors.white,
                        child: Ink(
                          child: InkWell(
                            child: Container(
                              decoration: BoxDecoration(
                                border: Border.all(color: Colors.grey[200],width: 0.25),
                              ),
                              alignment: Alignment.center,
                              height: 50,
                              width: (MediaQuery.of(context).size.width) / 3,
                              child: Text("${list[index]}",style: TextStyle(fontSize: 18,fontWeight: FontWeight.bold),),
                            ),
                            onTap: index == 11 ? onDel : (){
                              if(list[index] != "" && list[index] !="删除"){
                                onTap(list[index]);
                              }
                            },
                          ),
                          color: Colors.white,
                        ),
                      );
                    }),
                  ),
                ),
                // Column(
                //   children: [
                //     SizedBox(
                //       width: 60,
                //       height: 50 * 1.5,
                //       child: MaterialButton(
                //         onPressed:  onDel ?? (){},
                //         child: Text("删除",style: TextStyle(color: Colors.black,fontWeight: FontWeight.bold)),
                //         color: Colors.grey[100],
                //         elevation: 0,
                //         padding: EdgeInsets.all(0),),
                //     ),
                //     SizedBox(
                //       width: 60,
                //       height: 50 * 2.5,
                //       child: MaterialButton(
                //         onPressed: (){
                //           disKeypan();
                //           if(onCommit != null ) onCommit();
                //         },
                //         child: Text("确认",style: TextStyle(color: Colors.white,fontWeight: FontWeight.bold),),
                //         color: Colors.blue,
                //         elevation: 0,
                //         padding: EdgeInsets.all(0),
                //       ),
                //     ),
                //   ],
                // ),
              ],
            ),
          ),
        ));
  });
  initialization(overlayEntry);
}

/// <summary>
/// todo: 保持光标在最后
/// author: zwb
/// date: 2021/7/19 11:43
/// param: 参数
/// return: void
/// <summary>
///
lastCursor({@required TextEditingController textEditingController}){
  /// 保持光标在最后
  final length = textEditingController.text.length;
  textEditingController.selection = TextSelection(baseOffset:length , extentOffset:length);
}

/// <summary>
/// todo: 自定义键盘的删除事件
/// author: zwb
/// date: 2021/7/19 11:45
/// param: 参数
/// return: void
/// <summary>
///
delCursor({@required TextEditingController textEditingController}){
  if(textEditingController != null && textEditingController.value.text != "") textEditingController.text = textEditingController.text.substring(0,textEditingController.text.length - 1);
}

/// <summary>
/// todo: 打开键盘
/// author: zwb
/// date: 2021/7/19 12:04
/// param: 参数
/// return: void
/// <summary>
///
openKeypan({BuildContext context}){
  Overlay.of(context).insert(overlayEntry);
}

/// <summary>
/// todo: 销毁键盘
/// author: zwb
/// date: 2021/7/19 12:03
/// param: 参数
/// return: void
/// <summary>
///
disKeypan(){
  if(overlayEntry!=null) overlayEntry.remove();
}