序列化 DataTable 包括 RowError 和 "column errors"

Question

我想将带有 RowError 和列错误的 .NET DataTable 序列化为 JSON。我这样做：

var dt = new DataTable();
dt.Columns.Add("Col1");

dt.Rows.Add("A");

dt.Rows[0].RowError = "Test row error";
dt.Rows[0].SetColumnError(0, "Test column error");

var json = JsonConvert.SerializeObject(dt);

结果 JSON 如下所示：

[{"Col1":"A"}]

不包含行错误或列错误信息。

有没有办法序列化包含“错误”信息的 DataTable？

谢谢。

Answer 1

I want to serialize to JSON a .NET DataTable with RowError and column errors

如您所见，默认情况下，只有 ColumnName 及其值被序列化。要包含您想要的其他属性，您可以通过编写自己的 JsonConverter class 来实现，请参阅 Custom JsonConverter 了解更多信息。您需要两个转换器，一个用于 DataTable，另一个用于 DataRow。

*请注意，每个 class 都需要有这个命名空间：using Newtonsoft.Json;

CustomDataTableConverter

public class CustomDataTableConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType) => typeof(DataTable).IsAssignableFrom(objectType);

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            DataTable table = value as DataTable;
            CustomDataRowConverter converter = new CustomDataRowConverter();

            writer.WriteStartObject();

            writer.WritePropertyName("DataRows");
            writer.WriteStartArray();

            foreach (DataRow row in table.Rows)
            {
                converter.WriteJson(writer, row, serializer);
            }

            writer.WriteEndArray();
            writer.WriteEndObject();
        }
    }

CustomDataRowConverter

public class CustomDataRowConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType) => typeof(DataRow).IsAssignableFrom(objectType);

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            DataRow row = value as DataRow;
            JsonSerializer ser = new JsonSerializer();
            writer.WriteStartObject();

            // Serializes the row error property
            writer.WritePropertyName(nameof(row.RowError));
            ser.Serialize(writer, row.RowError);

            foreach (DataColumn column in row.Table.Columns)
            {
                writer.WritePropertyName(column.ColumnName);
                ser.Serialize(writer, row[column]);

                // Serialize the columns error description
                writer.WritePropertyName("ColumnError");
                ser.Serialize(writer, row.GetColumnError(column));
            }

            writer.WriteEndObject();
        }
    }

既然您已经有了所需的转换器，下面是您如何在您的案例中使用它们。请注意，我添加了另一个数据行以显示此处的差异。

 var dt = new DataTable();
 dt.Columns.Add("Col1");

 dt.Rows.Add("A");
 dt.Rows.Add("B");

 dt.Rows[0].RowError = "Test row error";
 dt.Rows[0].SetColumnError(0, "Test column error");

 dt.Rows[1].RowError = "Test row error B";
 dt.Rows[1].SetColumnError(0, "Test column error B");

 JsonSerializerSettings jsonSerializerSettings = new JsonSerializerSettings();
 jsonSerializerSettings.Converters.Add(new CustomDataTableConverter());
 jsonSerializerSettings.Converters.Add(new CustomDataRowConverter());

 var json = JsonConvert.SerializeObject(dt, Formatting.Indented, jsonSerializerSettings);

运行时，我的输出如下：

{
  "DataRows": [
    {
      "RowError": "Test row error",
      "Col1": "A",
      "ColumnError": "Test column error"
    },
    {
      "RowError": "Test row error B",
      "Col1": "B",
      "ColumnError": "Test column error B"
    }
  ]
}

还有一点要记住，我没有做这个的反序列化部分，只有序列化部分，但它是相似的。

序列化 DataTable 包括 RowError 和 "column errors"

Serialize DataTable including RowError and "column errors"

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