Question

我尝试动态创建csv文件并将流输出到浏览器。

这是我的api终点：

    [System.Web.Http.HttpGet]
    [System.Web.Http.Route("export-to-csv")]
    public FileStreamResult ExportDeposits([FromUri(Name = "")]DepositSearchParamsVM depositSearchParamsVM)
        {
            if (depositSearchParamsVM == null)
            {
                depositSearchParamsVM = new DepositSearchParamsVM();
            }
            var records = _DepositsService.SearchDeposits(depositSearchParamsVM);
            var result = _DepositsService.WriteCsvToMemory(records);
            var memoryStream = new MemoryStream(result);

            return new FileStreamResult(memoryStream, "text/csv") { FileDownloadName = "export.csv" };
    }

这是我的服务方法：

public byte[] WriteCsvToMemory(IEnumerable<DepositSummaryVM> records)
        {
            using (var stream = new MemoryStream())
            using (var reader = new StreamReader(stream))
            using (var writer = new StreamWriter(stream))
            using (var csv = new CsvWriter(writer))
            {
                csv.WriteRecords(records);
                writer.Flush();
                stream.Position = 0;
                var text = reader.ReadToEnd();

                return stream.ToArray();

}

以下是错误消息：

{＆＃34; message＆＃34;：＆＃34;发生错误。＆＃34;，＆＃34; exceptionMessage＆＃34;：＆＃34;错误   从“读取时间”中获取价值＆＃39; on＆＃39; System.IO.MemoryStream＆＃39;。＆＃34;，
  ＆＃34; exceptionType＆＃34;：＆＃34; Newtonsoft.Json.JsonSerializationException＆＃34;，
  ＆＃34; stackTrace＆＃34;：＆＃34;在   Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue（对象   目标）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues（JsonWriter   writer，Object value，JsonContainerContract contract，JsonProperty   成员，JsonProperty财产，JsonContract＆amp; memberContract，Object＆amp;   memberValue）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject（JsonWriter   writer，Object value，JsonObjectContract契约，JsonProperty   成员，JsonContainerContract collectionContract，JsonProperty   containerProperty）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue（JsonWriter   writer，Object value，JsonContract valueContract，JsonProperty成员，   JsonContainerContract containerContract，JsonProperty   containerProperty）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject（JsonWriter   writer，Object value，JsonObjectContract契约，JsonProperty   成员，JsonContainerContract collectionContract，JsonProperty   containerProperty）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue（JsonWriter   writer，Object value，JsonContract valueContract，JsonProperty成员，   JsonContainerContract containerContract，JsonProperty   containerProperty）\ r \ n at   Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize（JsonWriter   jsonWriter，Object value，Type objectType）\ r \ n at   Newtonsoft.Json.JsonSerializer.SerializeInternal（JsonWriter   jsonWriter，Object value，Type objectType）\ r \ n at   System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream（类型   type，Object value，Stream writeStream，Encoding   有效编码）\ r \ n at   System.Net.Http.Formatting.JsonMediaTypeFormatter.WriteToStream（类型   type，Object value，Stream writeStream，Encoding   有效编码）\ r \ n at   System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream（类型   type，Object value，Stream writeStream，HttpContent content）\ r \ n at   System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStreamAsync（类型   type，Object value，Stream writeStream，HttpContent内容，   TransportContext transportContext，CancellationToken   cancellationToken）\ r \ n ---从前一个位置开始的堆栈跟踪结束   抛出异常的地方--- \ r \ n at   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务   任务）\ r \ n at   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务   任务）\ r \ n at   System.Web.Http.Owin.HttpMessageHandlerAdapter.d__13.MoveNext（）＆＃34 ;,   ＆＃34; innerException＆＃34;：{       ＆＃34; message＆＃34;：＆＃34;发生了错误。＆＃34;，       ＆＃34; exceptionMessage＆＃34;：＆＃34;此流不支持超时。＆＃34;，       ＆＃34; exceptionType＆＃34;：＆＃34; System.InvalidOperationException＆＃34;，       ＆＃34; stackTrace＆＃34;：＆＃34;在System.IO.Stream.get_ReadTimeout（）\ r \ n在GetReadTimeout（Object）\ r \ n at   Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue（对象   目标）＆＃34; }}

Answer 1

Api正试图将<%@page import="java.sql.DriverManager"%> <%@page import="com.mysql.jdbc.Connection"%>序列化为json。那么，您是否会尝试更改MemoryStream;

ContentType

C＃MemoryStream - 此流不支持超时

1 个答案: