System.Text.Json.JsonSerializer 自定义实现序列化 DataSet、DataTable

System.Text.Json（从 .NET Core 3.1 开始），为了能够序列化这些类型，您需要为JsonConverter<T>您需要的类型实现自己的类型并在JsonSerializerOptions. 为您要求的特定类型编写一个序列化程序应该相当容易。

如果您不想自己实现，有简便的方法，请参考另一篇文章： JsonException: A possible object cycle was detected which is not supported 检测到可能的对象循环，这是不受支持的-CSDN博客

适用于序列化的示例（省略了反序列化组件）代码如下：

public class DataTableConverter : JsonConverter<DataTable>
{
public override DataTable Read(ref Utf8JsonReader reader, Type typeToConvert,
JsonSerializerOptions options)
{
throw new NotImplementedException();
}

public override void Write(Utf8JsonWriter writer, DataTable value,
JsonSerializerOptions options)
{
writer.WriteStartArray();

foreach (DataRow row in value.Rows)
{
writer.WriteStartObject();
foreach (DataColumn column in row.Table.Columns)
{
object columnValue = row[column];

// If necessary:
if (options.IgnoreNullValues)
{
// Do null checks on the values here and skip writing.
}

writer.WritePropertyName(column.ColumnName);
JsonSerializer.Serialize(writer, columnValue, options);
}
writer.WriteEndObject();
}

writer.WriteEndArray();
}
}

public class DataSetConverter : JsonConverter<DataSet>
{
public override DataSet Read(ref Utf8JsonReader reader, Type typeToConvert,
JsonSerializerOptions options)
{
throw new NotImplementedException();
}

public override void Write(Utf8JsonWriter writer, DataSet value,
JsonSerializerOptions options)
{
writer.WriteStartObject();
foreach (DataTable table in value.Tables)
{
writer.WritePropertyName(table.TableName);
JsonSerializer.Serialize(writer, table, options);
}
writer.WriteEndObject();
}
}

private static void DataSet_Serialization_WithSystemTextJson()
{
var options = new JsonSerializerOptions()
{
Converters = { new DataTableConverter(), new DataSetConverter() }
};

(DataTable table, DataSet dataSet) = GetDataSetAndTable();

string jsonDataTable = JsonSerializer.Serialize(table, options);
// [{"id":0,"item":"item 0"},{"id":1,"item":"item 1"}]
Console.WriteLine(jsonDataTable);

string jsonDataSet = JsonSerializer.Serialize(dataSet, options);
// {"Table1":[{"id":0,"item":"item 0"},{"id":1,"item":"item 1"}]}
Console.WriteLine(jsonDataSet);

// Local function to create a sample DataTable and DataSet
(DataTable, DataSet) GetDataSetAndTable()
{
dataSet = new DataSet("dataSet");

table = new DataTable();
DataColumn idColumn = new DataColumn("id", typeof(int))
{
AutoIncrement = true
};

DataColumn itemColumn = new DataColumn("item");

table.Columns.Add(idColumn);
table.Columns.Add(itemColumn);

dataSet.Tables.Add(table);

for (int i = 0; i < 2; i++)
{
DataRow newRow = table.NewRow();
newRow["item"] = "item " + i;
table.Rows.Add(newRow);
}

dataSet.AcceptChanges();

return (table, dataSet);
}
}

查看微软文档，可能会提供更多指导：

How to write custom converters for JSON serialization - .NET | Microsoft Learn

希望本文对你有帮助。