使用CSVHelper進行文件上傳

Question

我正在嘗試使用CSVhelper插件來讀取上傳的CSV文件。這裏是我的模型綁定器類：

public class SurveyEmailListModelsModelBinder : DefaultModelBinder 
{ 
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) 
    { 
     var csv = bindingContext.ValueProvider.GetValue(bindingContext.ModelName); 
     var file = ((csv.RawValue as HttpPostedFileBase[]) ?? Enumerable.Empty<HttpPostedFileBase>()).FirstOrDefault(); 

     if (file == null || file.ContentLength < 1) 
     { 
      bindingContext.ModelState.AddModelError(
       "", 
       "Please select a valid CSV file" 
      ); 
      return null; 
     } 

     using (var reader = new StreamReader(file.InputStream)) 
     using (var csvReader = new CsvReader(reader)) 
     { 
      return csvReader.GetRecords<SurveyEmailListModels>().ToArray(); 
     } 
    } 
} 

這些都是我試圖映射到對象：

• base {"You must call read on the reader before accessing its data."} CsvHelper.CsvHelperException {CsvHelper.CsvReaderException}：

  public class SurveyEmailListModels 
  { 
      [Key] 
      [CsvField(Ignore = true)] 
      public int SurveyEmailListId { get; set; } 
  
      [CsvField(Index = 0)] 
      public int ProgramId { get; set; } 
  
      [CsvField(Index = 1)] 
      public virtual SurveyProgramModels SurveyProgramModels { get; set; } 
  
      [CsvField(Index = 2)] 
      public string SurveyEmailAddress { get; set; } 
  
      [CsvField(Index = 3)] 
      public bool SurveyResponded { get; set; } 
  
  } 
  

  Visual Studio調試器，我得到一個錯誤內幕

Answer 1

不使用插件，但錯誤消息似乎很清楚。在訪問結果之前必須有一個Read()函數進行調用。嘗試將您的代碼更改爲如下所示：

using (var reader = new StreamReader(file.InputStream)) 
using (var csvReader = new CsvReader(reader)) 
{ 
    // Use While(csvReader.Read()); if you want to read all the rows in the records) 
    csvReader.Read(); 
    return csvReader.GetRecords<SurveyEmailListModels>().ToArray(); 
}