c# - 检查 CSV 文件是否为空/避免抛出异常

Question

如果我在一个完全为空的 CSV 文件上调用 csv.Read()，我会得到一个异常。有没有一种方法可以检查 CSV 而不必退回到 Catch block ？

var csv = new CsvReader(csvFile);

try
{
    while (csv.Read())
    {
        // process the CSV file...
    }
}
catch (CsvReaderException)
{
    // Handles this error (when attempting to call "csv.Read()" on a completely empty CSV):
    // An unhandled exception of type 'CsvHelper.CsvReaderException' occurred in CsvHelper.dll
    // Additional information: No header record was found.
    MessageBox.Show(MessageBoxErrorMessageExpectedColumns, MessageBoxErrorMessageCaption, MessageBoxButtons.OK, MessageBoxIcon.Error);
    return null;
}

Answer 1

您可以简单地检查文件长度是否为零

var csvFileLenth = new System.IO.FileInfo(path).Length;

if( csvFileLenth != 0)
{
  try
  {
    while (csv.Read())
    {
      // process the CSV file...
    }
  }
  catch (CsvReaderException)
  {
    // Handles this error (when attempting to call "csv.Read()" on a completely empty CSV):
    // An unhandled exception of type 'CsvHelper.CsvReaderException' occurred in CsvHelper.dll
    // Additional information: No header record was found.
    MessageBox.Show(MessageBoxErrorMessageExpectedColumns,              MessageBoxErrorMessageCaption, MessageBoxButtons.OK, MessageBoxIcon.Error);
    return null;
  }

}