参数类型为“Map<String，dynamic>？”不能分配给参数类型'SiparisMaster?‘

Question

参数类型为“Map？”不能分配给参数类型'SiparisMaster?‘。

如何将类型的对象转换为我想要的类？

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import 'package:json_annotation/json_annotation.dart';
import 'package:freezed_annotation/freezed_annotation.dart';

part 'siparis_master.freezed.dart';
part 'siparis_master.g.dart';

@freezed
class SiparisMaster with _$SiparisMaster {
  const SiparisMaster._();

  factory SiparisMaster({
    int? field1,
    DateTime? field2,
    int? field3
    String? field4,
  }) = _SiparisMaster;

  factory SiparisMaster.fromJson(Map<String, dynamic> map) =>
      _$SiparisMasterFromJson(map);
}

​

Answer 1

您应该为类创建一个方法或更好的构造函数，该构造函数接受Map作为参数

class SiparisMaster {
   SiparisMaster.fromMap(Map<String, dynamic> map){
      attribute1 = map['attribute1'];
      attribute2 = map['attribute2'];
   }
}

然后在函数copyWith中调用它

teslimat.masterDetayTemp = teslimat.masterDetayTemp?.copyWith(
   master: SiparisMaster.fromMap(masterObj)
)