尝试检查文件是否存在于路径中，但在 File 上出现构建错误。
File 是一种方法，不能在此上下文中使用。
if (!File.Exists(excelFilePath)) throw new FileNotFoundException(excelFilePath);
if (File.Exists(csvOutputFile)) throw new ArgumentException("File exists: " + csvOutputFile);
完整类代码
static void CovertExcelToCsv(string excelFilePath, string csvOutputFile, int worksheetNumber = 1)
{
if (!File.Exists(excelFilePath)) throw new FileNotFoundException(excelFilePath);
if (File.Exists(csvOutputFile)) throw new ArgumentException("File exists: " + csvOutputFile);
// connection string
var cnnStr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;IMEX=1;HDR=NO\"", excelFilePath);
var cnn = new System.Data.OleDb.OleDbConnection(cnnStr);
// get schema, then data
var dt = new DataTable();
try
{
cnn.Open();
var schemaTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
if (schemaTable.Rows.Count < worksheetNumber) throw new ArgumentException("The worksheet number provided cannot be found in the spreadsheet");
string worksheet = schemaTable.Rows[worksheetNumber - 1]["table_name"].ToString().Replace("'", "");
string sql = String.Format("select * from [{0}]", worksheet);
var da = new OleDbDataAdapter(sql, cnn);
da.Fill(dt);
}
catch (Exception e)
{
// ???
throw e;
}
finally
{
// free resources
cnn.Close();
}
// write out CSV data
using (var wtr = new StreamWriter(csvOutputFile))
{
foreach (DataRow row in dt.Rows)
{
bool firstLine = true;
foreach (DataColumn col in dt.Columns)
{
if (!firstLine) { wtr.Write(","); } else { firstLine = false; }
var data = row[col.ColumnName].ToString().Replace("\"", "\"\"");
wtr.Write(String.Format("\"{0}\"", data));
}
wtr.WriteLine();
}
}
}
如何解决这个问题？